Exercising in humidity and how to manage it

Summer has always been heralded as the time to get out, be active and exercise. The fine weather, warm conditions and late evenings invite us to get out and walk, run, cycle and play team sports. But despite the favourable conditions there is one aspect to our summer weather that seems to drive us crazy and leave us drained. Humidity.

Humidity is the amount of water vapour in atmospheric air and-when represented as a percentage-is termed ‘relative humidity’. The problem with exercising in high relative humidity is the higher the humidity, the less available oxygen there is for us to use. To test this hypothesis, simply try to breathe in steam coming from a pot or hot bowl of water. It’s very hard as the lungs cannot use/convert the oxygen-bound as H2o-as a source of oxygen to breathe.
The same occurs when we exercise in high humidity. So the body tries to compensate for the low levels of oxygen by increasing our breathing and heart rate and this can make regular exercise seem a lot harder than normal. Another factor that makes exercise hard is that the body finds sweating, and the evaporation of sweat from the skin, much harder as the atmospheric air already contains the water our bodies are trying so hard to remove. So, as we continue to exercise we get hotter. To combat this, the body increases the amount of blood to the skin to try lower our body temperature. The further down-side of that is that it means less blood flow to the exercising muscles, who in turn, fatigue faster.

So how do we cope with these humid conditions? My first piece of advice would be to take regular breaks in whatever it is you are doing. Drink cold water regularly when you do break and aim to take the intensity of your exercise down by about 30 percent.
Exercising in high humidity is not entirely unlike exercising at high altitude (there’s less available oxygen at altitude of course too). Climbers spend a lot of time conditioning their bodies to cope with the lack of oxygen by acclimatizing-spending increasing amounts of time at increasingly high altitudes. This slowly increases the amount of oxygen carrying red blood cells in the body and in turn increases the amount of oxygen available for physical exertion. Coping with humidity follows a similar path, the more you train in it, the better the body becomes by producing more red blood cells.

If you would like to contact Paul, ask his advice and book a session with him contact him at paul@moldphysiotherapy.co.nz or call him on 021 2244333.

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