From Olympic Run coach Bobby McGee- A few pointers on training in the heat, “Here are a few things, both scientific & more esoteric to consider:
As we get older we tend to be able to hold onto bio water less effectively.
- We need to drink quality water more frequently & accept that we’ll pee more as we’ll lose more of it. Water must be cool but not too cold to have it absorb best. It needs electrolytes so as to be better absorbed & to stay away from hyponatremia, hyper-hydrosis (increased fluid uptake) is good before long workouts & races (despite increased desire & need to urinate), hyponatremia is a dangerous condition caused by dilution of electrolytes through excess water consumption. This is why electrolytes are essential. Normally a condition that occurs with less fit athletes racing long distances on cool days & who are having a bad day & going easier than their relative fitness would normally allow & they are drinking habitually & thus too much too frequently.
- A touch of CHO also helps absorption it seems. Especially during WOs. Research here can be a bit confusing. Intensity is the critical factor when it comes to fat & CHO absorption & utilization as fuel.
Central cooling, I.e. From the inside, would seem more effective than from the outside, I.e. Cool drinks do more than cool application to skin. A light electrolyte solution in slushy form is good, Mitigating heat is easier than mitigating humidity. To mitigate these factors gradually increase exposure, BUT with increased fluid intake. Also minimize core temp build-up during warm up on these days: shorten WU, stay in shade, cool core through icee ingestion, do dynamic mobility drills & activation work in the shade rather than an aero WU in the direct sunlight. Use early part of running race, or bike in tri (if water is cool) to warm up. All this will delay core temp increase.
- Hats trap heat, hair traps heat… So hair should be up off neck or short & spiky, i.e. open to airflo. If eyes need help wear visor. Wear vented sunglasses that allow air flow. Sunblock can block pores, so consider chemical blocks versus mechanical blocks like zinc or magnesium dioxide. Mechanical blocks seem best for sunblock purposes, but may be warmer?
- Exfoliate regularly to remove dead skin to open pores to allow sweating. Do this before longer hot & humid races especially.
- Clothing must cool the skin & not the clothing – i.e. sweat must be evaporating from the skin & not the clothing.
In humid conditions carrying a sponge to continually wipe big surface areas is useful to allow for optimized evaporation.
- Lastly, in terms of absorption it would seem that less frequent larger amounts of fluid per ingestion are better absorbed than frequent smaller amounts. However the critical factor is mechanical comfort, i.e. can the athlete tolerate this amount of fluid per bout?”