Episode 39 - How to maximise your triathlon performance in the heat with Physiologist Avish Sharma

How to maximise your triathlon performance in the heat with Physiologist Avish Sharma

Have you got a hot race coming up? Here’s some practical heat adaptation advice from Physiologist, Avish Sharma. He was the lead Physiologist for Triathlon Australia in the preparation for the Tokyo 2020 Olympics which was always set to be a hot environment. 

In this episode we talk about:

• Why would you want to heat adapt yourself?
• Are there any negative implications of heat adaptation?
• How do you heat adapt yourself and how long do the performance gains last for?
• Practical suggestions if you have a hot race coming up like Cairns or Kona
• What to do if you live in a cooler environment but have to travel to a hot race? 
• Some suggestions for pre-cooling strategies you can implement to keep your core temperature down
  
  

Avish has so many practical, evidence-based ideas here to help you with racing and training in the heat.

Links:

To connect with Avish, follow him on Twitter

For further reading on heat acclimation, here are a few papers of interest:

Costa et al. 2012. Heat acclimation responses of an ultra-endurance running group preparing for hot desert-based competition. European Journal of Sports Science.
https://pubmed.ncbi.nlm.nih.gov/24444197/

Saunders et al, 2019. Special Environments: Altitude and Heat. International Journal of Sports Nutrition and Exercise Metabolism, 29: 210-219.
https://pubmed.ncbi.nlm.nih.gov/30676138/

Daane et al. 2017. Heat Acclimation Decay and Re-Induction: A Systematic Review and Meta-Analysis. Sports Medicine 48; 409-430
https://link.springer.com/article/10.1007/s40279-017-0808-x

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Episode Transcription

Episode 39 - How to maximise your triathlon performance in the heat with Physiologist Avish Sharma 

Taryn Richardson  00:00
Welcome to the Triathlon Nutrition Academy podcast, the show designed to serve you up evidence-based sports nutrition advice from the experts. Hi, I'm your host Taryn, Accredited Practicing Dietitian, Advanced Sports Dietitian, and founder of Dietitian Approved. Listen as I break down the latest evidence to give you practical, easy to digest strategies to train hard, recover faster and perform at your best. You have so much potential, and I want to help you unlock that with the power of nutrition. Let's get into it. 

Taryn Richardson  00:44
On today's episode of the podcast, I'm joined by Physiologist, Avish Sharma. He has done his PhD in Altitude Training at the Uni of Canberra and the Australian Institute of Sport. I had the pleasure of working with Avish in my role at Triathlon Australia and as part of data collection for some of the racewalker studies down at the AIS in Canberra. He took a lead role heading into the Tokyo Olympics for the triathlon team.

Taryn Richardson  01:09
He did a lot of work getting them to heat acclimatised and heat adapted for what was set to be a really hot environment. So he's perfect to join us on the podcast today to talk about heat acclimation and how to do it properly. He's moved on from Triathlon Australia days and is currently working with the athletics program down at the Victorian Institute of Sport. He's always a good chat. Avish loves a good laksa and I hope you enjoy the conversation today.  Alright, welcome to the podcast Avish.

Avish Sharma  01:40
Hi, Taz. How are you?

Taryn Richardson  01:41
I'm good. Thank you.

Avish Sharma  01:42

That's good.

Taryn Richardson  01:43
I miss working with you at Triathlon Australia. Those were good times, weren't they?

Avish Sharma  01:47
You were the first fun dietitian that I worked with. Actually, no, that's not true. I've worked with a lot of great dietitians, but I feel like we connected early on. Was it Supernova One I think, with the race walkers - maybe you came down for a little bit?

Taryn Richardson  01:59
Yeah, that's right. I helped with a race walker study - because you're an awesome human and we bonded over laksa.

Avish Sharma    02:05
Yes, that is one of many noodles that I enjoy eating.

Taryn Richardson  02:08
So I wanted to get you on the podcast today Avish because you are the master in physiology for heat adaptation. And you had some pretty good practice in the Olympics, heading into Tokyo with our triathlon team. But I wanted to give the age group triathletes listening, some tips for racing in the heat. Because in Australia, our age group season is very much in the hot part of the year. And even Cairns Ironman, which is in the middle of winter - it’s June for us - is still always a really, really hot race.

Taryn Richardson  02:41
And then this year, we've got Kona back on a timetable too which is in October, and that race is spicy hot. So I'd love to get people to start thinking ahead - to prepare what they're going to do for racing in the heat, and also their training leading up to stuff. Because it is a completely different kettle of fish compared to more of a cooler temperate environment. Before we get too deep into it, I do want people to go and listen to my 7 Tips for Exercising in the Heat episode. If you haven't listened to it already, it's episode number 16. It's got some really good nutritional tips for what to do if you're trying to train in the heat. But I've got Avish on today to go a bit deeper into, you know, how we heat adapt and the benefits of doing it. So that is why you're here, mate!

Avish Sharma  03:27
I'll do my best and give your listeners some practical advice and things that they can use in their own prep to help them race as fast as possible in some of their races coming up.

Taryn Richardson  03:36
Thank you. That is exactly what this podcast is about - translating that deep science into something that's practical, easy to understand that anyone can walk away with. So, thank you.

Avish Sharma  03:45
No dramas.

Taryn Richardson  03:46
Alright, let's get into it. Why, firstly, would someone even want to heat adapt themselves?

Avish Sharma  03:51
So usually, when you exercise, most of the blood that's flowing in your body is directed to your working muscles. But when you exercise in the heat, exercising normally, unadapted, will cause you to produce more heat than usual and faster. And so that can become quite detrimental to performance. And so one of the ways your body compensates initially is by directing more blood flow to your skin, so you can dissipate off more heat. But then, as a flow-on consequence of that, that affects your exercise performance. 

Avish Sharma  04:21
So basically, one of the reasons you heat adapt is to facilitate that process. And then over time, as your body adapts physiological processes will occur and then more blood flow will be directed to your muscle. And there'll be another series of adaptations such as reduced heart rate, skin, blood flow to help you dissipate heat better, sweat rates, and things like that, that'll help you thermoregulate better in the heat and preserve your exercise performance.

Avish Sharma  04:44
So hopefully that's a simplistic reason why you should heat adapt. And there are several different protocols that anyone (from an everyday athlete to professional athletes) can use to prepare themselves for such things. Also, there's actually quite a bit of research coming out now around, you know, doing heat training just to get fitter - not necessarily to prepare for exercise in the heat. Because a lot of the adaptations that occur through heat training are kind of similar to endurance training in terms of the same pathways that occur. We don't really have to get into it, but one of the ways we use heat training is to just add an extra stress into training for a variety of reasons.

Taryn Richardson  05:22
So heat adaptation is trying to get your body to exercise better in a hot environment. So it does all of these things to help your body cool itself down and make sure you still survive that process and don't die. Is there particular types of people or even perhaps different distances of triathlon, that it would be better for?

Avish Sharma  05:41
So for the listeners - I worked a bit with the Australian Triathlon team in the lead up to Tokyo. And so, given that most of the athletes on the team had two events, the relay and the individual - in a hypothetical world even if we had athletes just preparing for a 20-minute relay event, it would still be relevant for them to do some sort of heat preparation in the lead up to that event. Definitely for even a sprint distance and Olympic distance. And then, as the duration gets longer, it becomes even more relevant still. 

Avish Sharma  06:09
So half Ironman, Ironman distance, I mean, it's a very individual thing - who's susceptible to the heat. But thinking about other sports that are kind of outdoors, you're probably looking at that 5 to 10-minute duration and up, to do some level of heat preparation. But then for the shorter heat events, it's probably more about your thermal perception -  because even just feeling hot, if nothing is actually happening internally, that'll send signals to your brain to kind of slow down. Whereas, as the duration of the event gets longer your core temperature actually will be rising so it becomes relevant to put things into place to sort of help with that. 

Avish Sharma  06:48
So yeah, I would say if you’re in that shorter range - 5 to 20 minutes or 30 minutes, it's probably more about your thermal perception - that you need to find strategies to feel cool, because your core temperature won't get so high within that short timeframe to actually be that detrimental. But if once you get longer than that, you probably need to start more traditional heat prep and cooling strategies to actually lower your core temperature, either before the event or kind of mitigate the rise in core temp during events to help you perform a little bit.

Taryn Richardson  07:20
So some of those cooling strategies that you're alluding to would be ice slushie ingestion to do some internal cooling, some external cooling, like jumping in an ice bath, menthol - there's some research in that. Is there any other cooling strategies that I've missed?

Avish Sharma  07:34
No, not really, I mean, we can get into this now around our cooling strategies that we used in Tokyo. It was pretty mixed-method, sort of a combination of internal cooling strategies i.e like consuming something that will make you cold from the inside. External cooling strategies - so applying things on to you like an ice bath, a cold shower, ice vest towels, fans, all sorts of things like that. 

Avish Sharma  07:56
So we took the combined approach to get double the effect, I guess. And also that I think the main thing that we did was everything grounded in science, but a lot of rehearsal. A lot of athlete choice in what they did. Some athletes don't like having a high volume of fluid before they race so they focus more on their external cooling. Vice versa - I mean, no lean triathlete loves sitting in an ice bath for that long because you can get really cold. So we, through trial and error, found a water temperature that worked for us, but still had the physiological benefits, and then practice with varying lengths of immersion and things like that pre-race. And got people to do a full warm-up practice, so they'd be really comfortable doing it by the time we got to the Olympics and Paralympics.

Taryn Richardson  08:38
Did I see Emma Jeffcoat wearing an ice vest thing on the bike in her race?

Avish Sharma  08:42
No, I don't think so. But a lot of them would have warmed up with either an ice vest in some cases, or even just towels around their neck, under their armpits and things like that. So a lot of athletes, especially on stationary bikes would have had some sort of external cooling and combining that with either sipping on a slushie or having it more in like bolus form. So a large quantity at once, rather than sort of sipping it over time. But we can get into sort of the specifics of some of that later in the conversation if you'd like, Taz.

Taryn Richardson  09:09
Yeah, maybe I saw an image of her in her warm up with it on - that could have been what it was. Interesting to, kind of, not be there for once, but then, kind of, see all the stuff that was happening from the perspective of knowing roughly what was going on. Yeah, it's hard to sit in the sidelines in Australia, actually. Okay, so in terms of heat adaptation, we're trying to get the body to perform better in a hot environment. And we can help that process by doing heat adaptation strategies, plus some cooling strategies. Are there any negatives and any particular people that need to potentially not play with this sort of stuff?

Avish Sharma  09:48
Yeah, so like on the gender differences,I think that research is still emerging. So I don't think it's set enough yet that you’d be fully comfortable making an evidence-based recommendation off it. I think the main thing that we were concerned about with the heat training is just how much it takes out of you in a sport that's already pretty high volume. The elite athletes on the Olympic team and their colleagues that are representing Australia, they're training, I don’t know, 25 to 35 hours a week as a guide. There’s already a lot of physiological and physical stress on the body, and then you're adding in something else, again, which, in athletes that already find it hard to recover, pretty much do most of their sessions with non-optimal fuelling because it's physically impossible to get enough food in the hours in the day to fuel that many sessions. 

Avish Sharma  10:35
So anytime you add something on top of that really, without getting too kind of population specific here between different people, that's going to impair their ability to recover again. So it was something that we grappled with quite a lot, because we couldn't compromise the normal physical and physiological preparation of the athletes just to get heat training in. And so that's probably something that's probably important to remember, for the listeners - it's definitely important to integrate some sort of heat preparation for Cairns or Kona, or whatever race it is in the heat that you're preparing for, but don't do it such that it compromises your normal training. Because at the end of the day, the best thing you can do to perform well in the heat is be really fit in general. And then on top of that, add in some of these strategies that can give you that extra, you know, 1 - 5% improvement as well. 

Avish Sharma  10:46
So I probably don't have an answer in terms, of you know, which specific groups might be more susceptible. But the main thing to look out for is, in an already high volume sport, adding on an extra stress that can make people more susceptible to low energy availability and more susceptible to under recovery, and under fuelling, and all these other things that can be red flags to having a good performance.

Taryn Richardson  11:46
That's an excellent point, thank you. Because I know that people listening will be like, Yep, I'm definitely going to do this! Triathletes like shiny objects and like to be across all the things. So just a little, you know, stop point or check point in your thinking that if you haven't got all of that nutritional side of stuff optimised; you haven't got your nutrition periodised; your energy availability is on the sketchy side of things; then you don't play with something like this. This is when you've got all the other stuff dialled in - the sprinkles on the icing on the cake, right? It's the little top tier things that we can utilise when you've got that really solid cake foundation made first. 

Avish Sharma  12:23
Yeah, absolutely. And I think even within the modalities of heat preparation and cooling that you do, there are some that are probably lesser impact than others and more practically achievable.

Taryn Richardson  12:33
What would they be?

Avish Sharma  12:34
Even in preparation for Tokyo, I mean the COVID games as everyone knows! A lot of the athletes, as listeners would know, were sort of spread around Australia - if not spread around the world - in the lead up to a major competition. So we were buying Bunnings tents and setting up heaters inside those, spas and saunas post sessions, extra clothing indoors without a fan. Which is kind of an interesting one, because the two things you want when you're adapting to the heat is an increase in core temperature, and you want to sweat heaps, but the thing with the sweat response is you kind of want to facilitate it to evaporate because when it evaporates, you sweat more, whereas if you sweat and it just pulls on your skin, it dampens a sweat response. 

Avish Sharma  13:18
So quite often, people exercising to prepare for the heat won't exercise with a fan. And so what I would say is that's fine at the start - to get hot, quicker, but at a certain point, ideally, you want to promote airflow and promote evaporation of sweat off the skin to, again, promote that sweat response as much as you can. So even though we had access to things like testing in the lab and measuring heat responses in a bit more detail a lot of the techniques we use were pretty simple. Some of the athletes, literally, I had them, you know, either I went to Bunnings and bought a tent or had them go to Bunnings and buy a tent and set it up in a garage and had multiple gas and radiant heaters and things like that going. So it was pretty rudimentary a lot of the time. But you don't need much to be able to build a bit of a home setup and you can do it for less than 200 bucks, really.

Taryn Richardson  14:06
So is something like a sauna then not effective, because you're getting that heat, but then you don't have the evaporation of that sweat?

Avish Sharma  14:14
I wouldn't say that. I mean, it's like all of this stuff - as soon as you start increasing core temperature and producing sweat, they're going to be effective to a degree right? I wouldn't go and say it's not effective, but because we use a mixed methods thing and had to fit it in around people that are training sort of 30 hours a week, it was finding the most appropriate stimulus at a given time. 

Avish Sharma  14:35
So sometimes that would involve exercising in a heat chamber. Sometimes it involves sitting in a spa or a sauna, etc, etc. So as long as you’re heating most of those things at some point in a periodised way I think it's fine. Like some athletes all they'll have access to is a spa so I wouldn't not recommend they use that because they're going to be immersed the whole time and don't get as much evaporation as you know other modalities of heat - but they're still getting the core temperature increase, really. 

Avish Sharma  15:02
So, yeah, the first barrier to a lot of the listeners will be what can you actually access that's practical, and you can achieve in a timely manner, and then layering on some of the ‘need to haves’ versus the ‘nice to haves’ on top of that to get what works for you.

Taryn Richardson  15:17
How do you actually heat adapt yourself then? Like, we've talked about lots of different options and lots of different methods. But what is the protocol? Like how long does it take? What do you actually need to do to know that you've done some heat adaptation?

Avish Sharma  15:29
In terms of the timeframes, it kind of depends. So a lot of the research has been obviously in lab settings to measure responses and things like that. And it's going to be broken down into short-, medium- and long-term heat adaptation or heat acclamation. And so if you're doing consecutive days of heat stress, which again, we'll get to the fact that that's not necessarily practical for everyone. But just as a starting point, if you're doing consecutive days, you'll start getting a reasonable amount of adaptation within five days. So some of the first adaptations that you'll get are a stabilisation in heart rate. 

Avish Sharma  16:04
So for the same intensity of exercise, your heart rate progressively will get less each day until it reaches a point of maximal adaptation - after about a week. Your plasma volume, which is a component of your blood, will expand within the first week as well. And there are a couple of other things like that. However, the sweat response i.e. to help you sweat a little bit more in the heat to dissipate more heat, when you're exercising in heat, that probably takes more in the 10 days to two weeks range. 

Avish Sharma  16:30
So the simple answer is, most of the adaptations you can get within a week to two weeks and you'll have pretty much all adaptations in two weeks to a little bit over two weeks. So that's if you do consecutive days of heat training - which in terms of in the Tokyo prep - how we approached it was, in order to get those full range of adaptations, working with the coaches, we came up with a period in the season, whether it was straight after a race, or where it could fit in with training where we did try and chase those consecutive days of heat stress. Obviously, probably not so much right in the lead up to the event with the exception of being in a hot environment in the lead up to the event. 

Avish Sharma  17:10
So you obviously get some incidental heat stress there. But in terms of an actual intervention, using chambers, by saunas and stuff, we’re talking more about doing some of the work early. So it's two, three, four months out from the major event that we're preparing for going after a real block of consecutive days training there. So you know, a couple of the athletes that went with that approach, probably around Easter time, like April-ish, were able to get either 10 days heat done in 12 days, or, nine days straight or things like that. In this time, when you're competing with regular competition and other priorities in training, you take what you can get. 

Avish Sharma  17:45
So that was that, but then probably what's going to be more common for people is an intermittent approach. So maybe there are two days a week or three days a week. But obviously, given you're not having the consecutive nature of that you have to do it for a longer period. But fortunately, there have been some pretty good studies showing three sessions a week for three to four weeks can have some pretty good results in terms of some of the adaptations we talked about before. So there was a study in New Zealand in some highly trained runners that showed they did, I think, three sauna sessions a week for four weeks, and what that entailed was 60 minutes of low intensity exercise before - so just running. 

Avish Sharma  18:21
And then immediately after the session, sitting in a sauna for 30 minutes. So what's that? 12 sessions and they showed good improvements in exercise performance. I think it was measured with a treadmill test or something like that, and some changes in plasma volume as well. So something like that is pretty practically achievable for most people. I mean, a lot of gyms have saunas these days, or if not a sauna, a spa, at your local swimming pool. So that's something that is quite a good option for a lot of people.

Taryn Richardson  18:48
So the slow track would be maybe three sessions a week over a month, say, and you still have the same adaptations as nine days in a row? 10 days in a row?

Avish Sharma  18:58
I mean, everyone's individual. Some people will get a faster response than others - so whether or not you'll actually get the exact same adaptation. But to be honest it's not really what we're here for. It's just doing whatever you need to prepare for your event that you can manage. And even with some of the athletes it's all very, very periodised. There'd be some times where, just to get a bit of a stimulus in, we've started the athletes with just one session a week in the chamber - one 90-minute bike ride in the chamber, and that'll progress into two, once they got into it and then three. With some of these environmental stresses, as Taryn mentioned at the top, though, my background is in altitude training, and a lot of the way you think about heat and altitude can be quite similar. 

Avish Sharma  19:38
And there's a lot of research in the altitude literature around a cumulative effect over a long period of time. So like with repeated exposures (and we sort of had a similar philosophy with the heat stuff for Tokyo) is that some of the athletes there from places like Victoria or Tasmania, or Southern Australia, where peak temperatures in the summer are only in the mid to high 20s a lot of the time. As compared to northern New South Wales and Queensland where it's a lot hotter. 

Avish Sharma  20:03
So logic would dictate that they probably need a bit more heat work to get ready for something like Tokyo. But then you have to balance that out about how tired heat training can make you and how the.. some of the detriments of it. So we almost tried to take a bit of a long term approach - in that it's not just getting some heat work done in the six weeks before an Olympics or Paralympics - it's more about starting the conversation two years out or 18 months out and saying “When can we get regular doses of just a little bit just to top up the system and stress the body to make new adaptations that it hasn't necessarily had before”. And to try simplifying and make sense in an intuitive way, right? If you spend a lot of time in hot conditions or hot weather, you're probably going to deal with it, more so than someone that's come from the snow or something like that.

Taryn Richardson  20:48
Yeah, totally. The people that live in Queensland and train in Queensland and then race in the heat, you know, it's just normal for us. It's crazy hot, like we've just had a really crazy heatwave go through Northern Queensland. But then it's more so for the people that travel up from say, Melbourne and do Cairns Ironman in June, which is spicy hot and really struggle. 

Taryn Richardson  21:07
So it's those sorts of people that need to start thinking about it early and often and building that into their training. But I love that you said to start as far away as possible, because it is really going to stress the body and you need to make sure that you can still recover from that otherwise, there's no point adding that into your periodisation if it's just going to smash you,

Avish Sharma  21:27
One of the athletes that I worked with, and that you would have worked with as well, Taryn - she, earlier in her career, had quite a few negative experiences in the heat - some races that she couldn't finish because of how hot it was. And she just took a really long-term methodical approach of probably two or three times a year doing two or three week blocks of just getting in the heat chamber. And a coach would write her sessions and she'd get them done down at the Sports Institute that she was working with. And that culminated in a world championship medal in quite a hot race. You know, the body is very malleable in terms of adaptations, right? If you expose it to a stressor, often enough and regularly, you'll get a response in time.

Taryn Richardson  22:04
That's really good advice. Thank you, Avish. So if somebody is heat acclimatised, how long do those adaptations last for?

Avish Sharma  22:12
So there's been some reasonably cool research done on that and it was quite influential for us people like myself that are coming up with these plans for athletes to get them ready for an Olympics and Paralympics. So there's some research out there that showed that if we had people that were fully heat adapted, i.e. you know, their heart rate for a certain intensity had stabilised again, they were sweating a lot more, plasma volume has expanded, and all that.

Taryn Richardson  22:39
Which you can test for in the lab - an age grouper can't do that sort of thing. But yes.

Avish Sharma  22:42
To be honest, though,I think one of the questions earlier was “How can we kind of know that it's actually working?” In something simple - like on day one of your heat session, if you want to just jump in, do something like ride really easy, but keep it fixed for 20 minutes and just measure your heart rate, and write down out of 10, how hard it is. And then after your sessions repeat the exact same thing, you shouldn't see a change. If you haven't seen a change there, that means that you probably haven't quite got it right. And maybe you can get some help from a physiologist or a dietitian about “What are the things that I'm doing that might not be optimal here?” 

Avish Sharma  23:18
So I think the main message here is you don't always need the shiniest lab facilities and things like that, to actually measure what you're doing. I think simple tools that are readily available, I would always recommend using that. But anyway, in terms of on decay, someone that's fully heated adapted, you need to maintain the stimulus every two to four weeks, depending on the individual. So someone's gone and done the seven days in a row heat prep, but then they do nothing for six weeks, he'll essentially probably have to start from zero again. Whereas if you do what's called a top up session - so you don't have to do a full seven days again. 

Avish Sharma  23:55
I think as long as it was within, yeah, that two to four weeks, depending on the individual, they retained a lot of the adaptations they've got the first time, so then you need to do less sessions to get back up to 100%. So that was how we did it - a longer block of three to four months out and then some maintenance. We spent a bit of time in Cairns, a couple of months out from the Olympics and Paralympics as well. And then the final lead up was really just one or two sessions a week. And then by virtue of COVID, we had to be in Tokyo five or six days before the event anyway, so then there's your natural heat stress there. So hopefully that sort of paints a picture to the listeners of a combination of different approaches over different times with ideally no more than a month in between exposures to help retain that stimulus and adaptation in the body.

Taryn Richardson  24:44
Some really good advice there for different ways that you can do it. There's no one fixed approach, but like you said earlier, it's got to be either a week or two every day - back to back or building up to three days a week over three to four weeks to try and get that same performance enhancements that we get from the solid block together.

Avish Sharma  25:03
For the listeners and the age group triathletes, I'd probably honestly start with what can you achieve that fits in with your training commitment to the lifestyle overall, etc, etc. Like the athletes in the past, not in triathlon, but in other sports, doing 10 weeks straight of heat prep, but only one or two sessions a week, because that's what worked in with all their other goals. So if you can only manage a lesser amount of sessions weekly, just do it for a longer period of time. But if you can actually say, "Oh, actually, you know, I can do probably five sessions this week." Well, then you probably only need to do one or two weeks of that.

Taryn Richardson  25:36
Or if you live in Queensland, it's just every day, so it's all good. 

Avish Sharma  25:38
Well, it was funny on that, because I think we got to a point that I was definitely recommending for the Queensland based athletes to almost get out of Queensland for a month in summer just to train in some cooler weather and actually be able to …

Taryn Richardson  25:53
Hit some targets?

Avish Sharma  25:53
Yeah, exactly. So it's almost like reverse heat training. And just training quality and things like that become quite difficult to time when you're getting these oppressive heat waves. And it's just so humid all the time in Queensland. So yeah, it's all about balance and getting everything you need, really.

Taryn Richardson  26:07
So if somebody lives in a cooler environment, but then has to travel for a hot race. Do you have any advice for them to try and maximise their heat adaptation heading in?

Avish Sharma  26:17
Yeah, I’d probably start at the event and work backwards, right? So the first step would be how long can you be in the venue before the actual race? If there's some people that can be in Kona for two weeks before the actual event, that lessens the amount that they need to do in the lead up, because they're going to get a hell of a lot of adaptation from being there - and doing their final preparation in those conditions. Even in that, one of the things that we had to consider was for athletes that hadn't had heat in a long time. And then, in our case, putting them in Cairns for three weeks, you almost have to prepare them for that, itself. Even those athletes still did a little bit of heat prep, just to kind of get that adaptive stimulus going and body used to some of those things. Because the last thing you want is to be able to go to a training camp and then you're so cooked all the time that you can't actually train properly and things like that. 

Avish Sharma  27:12
So it's a similar thing here with Kona, I think, for me, regardless of how much time you can spend there before the race, whether it's three days or 14 days, I'd probably still advocate for doing some sort of prep throughout the Australian winter - just because the more you get used to it, like the less of an impact it will have, at the time. Whereas if you're doing heat prep, for the first time ever, like less than three weeks out from the race, it's going to knock you around a fair bit. So it's almost like getting that really unfriendly period out of the way early so then you can actually focus on your training, that was probably the main philosophy we took with our heat preparation with the Olympic and Paralympic triathletes - was that the discussion with the coaches, "Alright, what are the key periods of training that you don't want, like any kind of interruptions in and you want them to be going really well?" And once you find out those ones, then it's, “Okay, well, you can't do any heat training there, really, unless you're kind of in a warm-ish environment”. 

Avish Sharma  28:09
So Cairns in winter is not too bad - it gets up to high 20s, low 30s, which is manageable. It's not oppressive, like it was in Japan. So the training quality still -  you're able to still get a fair bit done, but we looked at other periods that would be more suitable to really give the athletes stress, and we can build in more recovery and things like that. So where volume and intensity weren't really so much of a priority. And then we have to manage that with recovery as well. So it's a puzzle, but it doesn't need to be an overly complex puzzle. It's just like, listen to your body still, you know, support yourself well, with adequate nutrition and sleep and things like that. But yeah, it's just about sort of periodising in it when it will work.

Taryn Richardson  28:48
People hear me say the word periodised all the time. So I'm glad that you're saying it too. One of the things that is useful with triathlon, is you do a bit of pre-cooling by jumping into the swim, right? You get into a colder temperature than is your body temperature. So you can do a bit of pre-cooling that way. But what about for swimming in environments where the water is not actually cool - you get in and it's a bit of a bath?

Avish Sharma  29:09
Yes, that was probably one of the most unique challenges about Tokyo and something that we found interesting to work through. So I mean, intuitively, you'd be like, well, if it's hot outside, you’ll sort of do heat training with the heater and on a bike or running. So your logic might follow that “Oh the water’s going to be warm -  let's just do a ton of swimming in hot pools or learn to swim pools or swimming with a wetsuit."

Taryn Richardson  29:31
Not nice.

Avish Sharma  29:33
Actually, the physiological evidence for it isn't actually that strong. Whereas 14 days of heat training or sitting in a sauna and all that stuff works, and there's quite a lot of evidence for it. The studies that have shown a similar approach for swimming in water temperatures in the low 30s, which gets quite oppressive. The adaptations aren't as good. However, what you probably do need to do, and what we sort of tried to work on, was it's still going to feel terrible when you jump into the ocean or river or whatever it is, and it's like 32 degrees or 31 degrees or whatever. 

Avish Sharma  30:09
So what I would suggest is working on the perceptual side. So it becomes really familiar to you. So that way you can get your brain used to it and still push when you need to. So we had our athletes at various times, again, in a periodised way, completing some of their sessions in learn to swim pools or with a wetsuit on. Or if we were fortunate enough to have natural hot water, we would seek that out. 

Avish Sharma  30:32
So just to get that mental adaptation to "Okay, this is what it's going to be like". The first time you want to be swimming in 31 degree water is not the race - try and set yourself up to experience that beforehand. People seem to be really attuned to really small changes in water temp, and the difference between 27 and a half and 28 and a half is a lot different to the same difference in air temperature.

Avish Sharma  31:05
So even if you can get to a 30-degree pool, it might not be exactly the same as what you're going to be swimming in a race. But something is better than nothing. Some of our athletes probably did, in the couple of months leading up, maybe five or six swims in really uncomfortable water just to get used to the whole notion.

Taryn Richardson  31:14
Do you want to talk a bit more about pre-cooling? Like any specifics around what people could potentially do in that space at home, like slushies, ice vests, that sort of stuff? Like say somebody raising Cairns or racing Kona, or even just our, you know, short course race schedule in really hot environments. What sort of things could people practically do in that sense to keep their internal core temperature down?

Avish Sharma  31:37
So I guess the most basic one is slushies. And it's pretty easy. I'm sure you've got a killer slushy recipe Taryn, but the one we used was two parts ice, one part water, one scoop of whatever electrolytes/sports drink powder - is sort of having chucked that all into a NutriBullet. Give it a bit of a blitz. And that's the makings of a pretty basic slushy. Because Tokyo was so oppressive, we were adding things like glycerol or extra sodium into the slushies as well. 

Avish Sharma  32:02
Again, to the athlete’s taste - with a variety of different sports drinks that worked for them and came up with a formula that worked for each individual. So some athletes loved having a Red Bull before the race, so we'd make them a Red Bull slushie. Others we're pretty comfortable with whatever brand of sports drink that they were used to - so we'd make it out of that. So we've had a pretty bespoke way with our slushies, which I think worked quite well, and people were quite practiced with it. The thing that probably takes a little bit of getting used to with slushie is the manner in which you drink it. 

Avish Sharma  32:33
So the base recommendations from the literature are 7 grams, or meals per kilo of your bodyweight. So if you're a 60 kilo person, that's roughly 400 mls of slushie, that you want to be consuming. And I think to really get that drop in core temperature - you want to consume a lot quickly. What we would get our athletes to work towards was, generally pre-race for most of the athletes, centred around their swim warm up, which takes place at a fixed time, you always have to be out 30 minutes before or whatever it is before the race. And so we've got to put that in first and then schedule around that. And so what we generally advocated was try and drink half in one go right before you swim warm up, and then half, somewhere in between finishing your last bit of exercise, and then the race start. So that's something you definitely need to work towards - to get the maximal effect and just ingesting that much at a given time.

Taryn Richardson  33:34
So any tips on how to get that in quickly without getting a massive brain freeze?

Avish Sharma  33:30
No (haha). Literally, there's ‘try and not swirl it around in your mouth for too long’, just get it down. And we use spoons and straws and things like that. So even though you're taking in a lot over time, you're not taking massive gulps -  it’s lots of small gulps - if that makes sense? So that's probably the main one with the slushies. Ice vests are pretty self-explanatory to be honest. But if, I mean, ice vests aren't the most accessible things, but what’s something that we used with varying degrees of success (but it sort of depends on how you use them) is ice towels. And it's as simple as it sounds-  get a towel, fill it with ice or dunk it in ice water, wring it out and keep it around your neck, armpits, those sorts of areas. Between your legs.

Taryn Richardson  34:17
For the regular listener, that's where a lot of blood flow is - in those areas. So it's going to go right centrally, if you can put it under your armpits, in your groin. There's big blood vessels in there that'll take that back to the heart.

Avish Sharma  34:29
Absolutely. So that probably works best though if you've got time pre-race to just sit and relax. It doesn't work so well if you're trying to have an ice towel around your neck when you're walking around or like still exercising and things like that. So yeah, if you've got periods of time where you can just sit and relax, that's a good one - that's relatively easy to do on the fly with just a couple of towels that you've got from your hotel or your race pack or whatever. And hopefully there'll be plenty of hotel ice machines or something like that, that you can get a bit of ice from. 

Avish Sharma  35:00
Even with slushie - if you don't have a blender handy - freezing a Powerade or whatever drink of choice overnight and just smashing it up the morning of and consuming the ice. The key thing with the slushie is, that because the heat transfer from ice, when it changes to liquid, is a lot better than just having a cold liquid, it does make a difference - having an icy drink rather than just super cold liquid. Cold liquid will still help if that's all you can do. But yeah, the key really is to get that ice slurry. And then ice baths and things like that. Anything below, probably, I don't know, 21°, 20° is quite uncomfortable most of the time. But if you have a bit of time, you can have a progressively graded cold shower - gradually drop the temperature here and there. Plenty of little options there for people to have a play around with and find what works for them. But really what you want is to get a bit of a drop in core temperature before the race. So it almost gives you a bit more room. 

Avish Sharma  35:54
The difficult thing in triathlon is the front end of the swim is essentially a sprint - like it's full intensity. So you want to have a colder core temperature, but you don't want to compromise muscle temperature whatsoever. So as we got closer to race start, the internal cooling techniques took over as the dominant ones. Whereas pre warm-up, an hour to two hours before we'd have the ice bath and things like that if athletes wanted to use them, but then they'd still have time through the warmup to get back up to regular muscle temperatures and things like that. Whereas in other sports, it's a bit more of a graded intensity started at the beginning of a race. So having really high muscle temperatures probably isn't as critical as it is in triathlon. So the message here is you don't want to cool down so much when you're preparing for a triathlon just because of the nature of the swim. So that's something to keep in mind as well.

Taryn Richardson  36:44
Well for the short course racing like sprint and Olympic, where you want to sort of go guns blazing at the start compared to say a bit more like 70.3 Ironman distance where you're warming up as you go, because you're out there for so long - different strategy for those sort of different distances. Could you have a slushie on the bike in your bottle, if you can get it to stay that slushie consistency, that's the challenge.

Avish Sharma  37:05
In a word, yes, but the main challenge there is the actual logistics of getting it done. A lot of the athletes froze water bottles or drink bottles overnight. Because a lot of the time at ITU racing or World Triathlon or whatever it's called now you have to rack your bottles a predetermined time before. I'm assuming it's the same in age group racing. So if you're racking your bottles two hours before, within that two hours, it'll probably melt a little bit so you can get a nice little consistency there. And that seems to work quite well in hot races. We definitely invested a little bit in some insulated bottles, which are all commercially available for anyone who's interested - those seem to work reasonably well as well in terms of keeping the fluid, whatever was inside, reasonably cold.

Taryn Richardson  37:46
It's something that you could test out beforehand. Like if you know roughly what time it is between transition closing and when your wave start is - estimate when you'll then be on the bike, freeze your bottles overnight in like, Camelback do them, those insulated bottles, but there's other brands as well. And leave it out from that time and see what happens to it and see if it is still cool or if it's frozen in a brick. You don't want to get onto the bike and have your water or fluids or whatever, completely frozen, not consumable. But then you know, you're not getting any benefit, I guess if it's completely melted, too, but you know, you still need your liquid on the bike.

Taryn Richardson  38:19
So you can actually test that in a training situation and see what happens to it.

Avish Sharma  38:24
Absolutely.

Taryn Richardson  38:25
Well, thank you so much for joining me, Avish, so many awesome practical things that people can walk away with. Little bit of a word of caution, though, is that you wouldn't really dabble with stuff like this, unless you've got everything else nailed first. You know, you've got a really good training program, and you're absorbing your training, you're not just absolutely smashed at the end of the training week. And also that you've got your nutrition periodised to that - you know, you know how to eat for light days, you know how to eat for moderate days, you know how to eat for hard days. Because if you layer in these more performance enhancing strategies, your body needs to actually absorb them to get better. If you're not absorbing that, then you aren't really getting that benefit, are you? You're just smashing yourself and putting yourself into more of a hole, which is not ideal either.

Avish Sharma  39:09
I completely agree with all of that. And the good thing is that there are some less invasive, and less potentially risky, strategies. So a starting point might literally be considered doing your run early in the morning. Maybe try and fit it in, in your lunch hour instead, in the middle of the day. That could literally be step one - just a little bit of extra heat stress there and doing that consistently over a month - that will already have an effect. It's helpful to think about “What little things that I can do that won't cause that much of a threat to my overall training?” as a starting point. And then if you're handling all that really well and you find you're progressing then you can maybe add something in like a spa or sauna, or whatever. And, if that again goes well, then maybe you can buy an extra couple of heaters and chuck them in your laundry and go there as well. So plenty of different ways to approach the problem but/and whilst the heat training is an important aspect of preparing for competition in the heat, it's not going to replace being fit in the first place and healthy eating and having a good balance between all your training and everything else.

Taryn Richardson  40:11
Yeah, good advice. So if people want to hear more from you Avish, where do they find you?

Avish Sharma  40:16
I'm on Twitter. I think it's a @AvishSharma5, I mostly tweet about work related stuff and publications and things like that. But if people want to get in touch, I think they can probably send me a message on that or just follow what I'm interested in.

Taryn Richardson  40:30
Yeah, I might link a few papers in the show notes, too. If people do want to read a little bit further about heat adaptation and how to do it, and some pre-cooling stuff too. There's a few people that do want to read a little bit deeper. So I'll put some of those in the show notes too.

Avish Sharma  40:42
Absolutely.

Taryn Richardson  40:44
Thank you so much, Avish. Have a great day!

Avish Sharma  40:46
And you. See yah!

Taryn Richardson  26:56
Thanks for joining me for this episode of the Triathlon Nutrition Academy podcast. I would love to hear from you. If you have any questions or want to share with me what you've learned. Email me at [email protected]. You could also spread the word by leaving me a review and taking a screenshot of you listening to the show. Don't forget to tag me on social media at @dietitian.approved so I can give you a shout out too. If you want to learn more about what we do, head to dietitianapproved.com. And if you want to learn more about the Triathlon Nutrition Academy program, head to dietitianapproved.com/academy. Thanks for joining me and I look forward to helping you smash it in the fourth leg - nutrition!