The shoulds and shouldn’ts of exercising in the heat

I am lethargic, tired

Q

and can’t even bring myself to exercise in this heat. Can you help?

We know almost everyone

A

in SA is eminently corruptible but even if we did manage to slip a note with our democracy’s founding father and a spotted wildcat printed on it under the weatherman’s door, it wouldn’t help. As you know, we are not experiencing global cooling.

I am acutely aware it requires almost supernatural motivation and dedication to rack an Olympic bar or pull on a pair of running shoes when flushed, sweaty and lethargic. That, or an uncompromising training partner.

Imagine this: the day is going just fine in a cool office and then you need to run a few errands or fetch children from school. You drive around in the heat for an hour, walk up and down tarred parking lots with heat blasting from beneath and above you. Another power cut and the fans aren’t running. The office is now warm, maybe even hot. You feel a lot less energised for the last few hours of work, never mind exercise.

The reason we feel like this is because our bodies are working hard to keep us cool. Scientific American quoted the regional medical director at Duke Health in North Carolina, Michele Casey, as saying that this extra “labour” is what makes us feel tired.

“Your body, especially in the sun, has to work hard to maintain a consistent, normal, internal temperature,” Casey is quoted as saying. Some of this work includes dilating our blood vessels, which allows more blood closer to our skin’s surface, which allows it to cool down. It is why some of us look a bit red in the heat.

We perspire and then cool down when the sweat evaporates, but Casey says this requires an increase in our heart rate and metabolic rate. Essentially, your body needs to use more calories to function

— there is always a silver lining at The Water Cooler.

Casey says many people are always slightly dehydrated. It’s crazy to read that but then consider how many people actually drink water. As the heat increases, or as they start to exercise, this dehydration becomes worse. Ever see athletes from cooler climates rolling around grasping cramping muscles near the end of a sports game? Now you know why — the heat, dehydration and loss of salts through sweating has literally floored them.

Our performance, strength and endurance will decrease as it gets hotter, less so for the more conditioned and fittest among us. However, when pushing too hard in the heat it can become dangerous, where fatigue or cramps are replaced by heat exhaustion or even heat stroke. Use common sense and don’t attempt to go for a 15km run at 1pm during a heatwave if you are a casual runner.

If you can help it, choose to exercise during cooler times, or indoors where the cooling works. Drink fluids before, during if you can, and after exercising.

Many resources say the colour of your urine will let you know whether you are getting enough water — if it is dark, you are not drinking enough water. Use common sense — while dehydration is the most common cause, this is a crude measurement as dark urine could also signal other conditions.

Stay away from alcohol — you should never drink and exercise, and avoid too much coffee or sugary drinks. Water is the best thing to drink, but during long, intense bouts of exercise a low-sugar sports drink can help replace minerals or salts lost during sweating. Wear light fabrics, and if outdoors choose lighter colours. Use sunscreen because sunburn will make it worse, and wear a hat or cap.

A cooling towel on your neck and head is said to work wonders. I have read the odd opinion here and there that in theory you could trick your brain into overriding your Godgiven

natural thermostat and train to a dangerously high internal body temperature. Use it to cool down, not to break yourself.

I find a cool shower or swim before and straight after exercise does the trick.