Working out in the heat

Working out in the heat.

Working out in the heat does put extra strain on the body and a few people have asked why. I have just read a pretty dry medical paper on this which I will try to explain.

What is happening in your body?

Firstly your core temperature rises rapidly which is coupled with the body’s main cooling system (the skin) being less effective. This is because usually the temperature of your skin is lower than the 37C average core body temp but when the heat is up the skin can be hotter than your core temp.

Blood is then diverted to the skin surface via capillaries to produce sweat which then evaporates to cool then skin and help reduce core temperature.  This results in less blood being available to the heart to pump to the muscles.  This blood carries oxygen which is vital for energy production and when this is lacking we revert to an anaerobic (without oxygen) energy system which can only last 90 seconds before you run out of steam and start gasping for breath.

In addition sweat pulls more than heat and water from the body, it also pulls out sodium, potassium, and other minerals needed for muscle contractions, nerve transmissions, and water balance. To counter these losses, the body begins secreting hormones that help the body hold onto water and minimize mineral depletion.  This is also a reason why you can increase weight after summer workouts, it is just water.

How we make it work for us

If you train in adverse conditions and you have a fairly decent basic fitness level the adaptations your body needs to make can increase your ability to perform in more regular conditions. There is a study performed by the university or Oregon which looked at the effects of heat. acclimatisation on top level cyclists.  They observed a marked improvement in performance after 10 days of training in 100F heat (this is America they use old money!).

We utilise interval training so the CV element does not last beyond 90 secs before a rest period (I know it feels longer).

We take advantage of the  weather to focus on strength training and flexibility.

How to be prepared

  • Accept and adapt to reduced performance
  • Hydrate before, during and after a workout.  I find that drinking too much while I am working out makes me feel queasy so I hydrate in the hours before.
  • Wear light and loose clothing.
  • Use a high SPF

Interesting hydration ideas

Plain water can be a bit dull so these are great variations:

  • Handful raspberries or chopped strawberries, mint, ice added to plain or sparkling water.
  • Add slices of either lemon, lime. orange an a squirt of the juice to cold water.
  • Make a very strong fruit, herbal or peppermint tea (2 bags 1 cup) cool in the fridge and add to jug of iced plain or sparkling water.
  • Place bottle of gin in freezer for a few hours, mix a generous measure with ice cold tonic and lots of ice, garnish with lemon, lime or whatever suits your particular gin – enjoy AFTER your session!