With Cairns Ironman just around the corner, I’m deep into writing race nutrition plans for our athletes. This morning on Coffee & Questions I wanted to share with you some strategies to assist with training and racing in the heat.
One of the biggest impacts of heat exposure when exercising is its effects on the gut. This is exacerbated when our core temperature gets >39°C
All of this happens with exercise – the longer and more intense – the worse it is. And it is exacerbated by heat exposure
So what do we do about it?
Exposure to hot over 7-14 day period. 10-14 days optimal
Expands plasma volume – enhanced fluid balance – reduced HR – decreased rate of perceived exertion
Increased sweat rate – but interestingly sweat [sodium] decreases to conserve
Sweat sodium loss is the same or lower following acclimation
IT MAKES NO SENSE to start sucking back heaps of sports drink when you head north
All you’re doing is messing up your body’s natural adjustment
Increase sodium too early, increase filtration in the kidneys
Rate of decay ~2.5% per day without heat exposure
Better PV retention
Sports drink was originally designed to drives thirst – increases ad libitum fluid intake
Reminder – don't simply do what a packet tells you to – generally it's marketing designed to help you buy more of their product or stick with their brand
Seek professional advice when it comes to training and racing nutrition to find a holistic plan that's practical and evidence-based.
HOW MUCH SODIUM do you need?
It depends – you need to understand how you sweat.
You shouldn’t just take salt tablets because your training buddy told you to
Develop an Individualised protocol based on your sweat testing results in the same environmental conditions
If you're interested in doing sweat testing, learn more about how it works and when our next session is HERE.
<22°C will increase palatability – you’re more likely to consume
<10°C – additional benefit but NOT LIKELY TO BE PRACTICALLY POSSIBLE IN CAIRNS (without outside help)
There is no benefit in salt loading for multiple days before when you go to a hot environment
There is a benefit to acute loading – 1-2hrs prior to the race start
Highly individual – I’m not going to tell you how to do it in this forum as it’s not something to mess with
If you want an evidence-based plan specific to you – you can book a consultation with me HERE
3-carbon alcohol taken off the WADA banned list in 2018
Assist with fluid retention pre-event – expands PV and decreases urine output
This is a sprinkles on the icing on the cake strategy - nail all of the others above first before doing this one with a professional qualified to give you the right advice
Alters thermal sensation in the mouth
Activates oropharyngeal cold receptors – increases the threshold temperature for their activation – creates a feeling of coolness
DEFINITELY – test first
Use commercial products – risk for toxicity
Again, this is a sprinkles on the icing on the cake strategy – there are 5 strategies listed above to trial before you would even consider this one!
If you want help putting into practice any of the strategies above, or are looking for a Sports Dietitian to help you with training and racing nutrition, learn how you can work with me HERE