How can I cool down fast after an outdoor workout in a hot & humid climate?

Question

I live in a tropical city, and with treadmills in air-conditioned gym off limits due to Covid, I've recently taken up predawn jogging. However, while the jog itself is still tolerable, after I stop running I still find myself flushing bright red and pouring out buckets of sweat for up to half an hour afterwards. So:

What's the fastest way to cool down after working out in a hot & humid climate?

Things I've tried:

• Staying in an air-conditioned space. Does not seem to be very effective.
• In more temperate climates, I was a big fan of cold showers, but here even "cold" water is outdoor temperature, meaning around 30°C/86°F, so I'm still sweating the moment I step out.
• I do have access to an outdoor plunge pool, which is not much cooler than the shower, but seems reasonably effective. But am I best off using it to float motionless, stretch my muscles, swim very short laps or sit submerged on the bottom using a snorkel?

Note that I've seen What is the best way to cool down after a workout?, but it seems to assume a cold climate, because I'm pretty sure the current top answer's advice to "wear a long sleeve shirt" would not be helpful here.

Answer 1

I was living for many years in South India and training daily in Kalari (a martial art). In Kalari we have a simple method to deal with this problem. After training, we wait for the body to stop sweating before going into the shower. It is said that if you cool the body too soon by showering (i.e. whilst the body is still in a high metabolic state and producing a lot of heat), that you can cause imbalance to the humours. This is of course an Ayurvedic understanding but the principle makes sense. Allow the body to cool naturally, before cooling it further with water.

It is also good to avoid rubbing sweat off with a towel as this is said to push the toxins back into the dermis layer under the skin. Better to 'dab' the sweat off with a towel than 'rub' and even better to allow it to evaporate (and then shower).

Answer 2

I feel the same way after erging (rowing) a moderate (20 min) piece on my rower whether indoors or outdoors. I think the most important consideration for cool down is to reduce the amount of stress on the body gradually. I accomplish this by performing various stretches. The stretches serve two purposes. They give me a chance to relax after a tough workout, and, they aid in my recovery by helping to reduce muscle soreness and maintain my range of motion.

A paper titled, Do We Need a Cool-Down After Exercise? A Narrative Review of the Psychophysiological Effects and the Effects on Performance, Injuries and the Long-Term Adaptive Response, specifically addressed the use of static stretching as a recovery modality for runners. It found:

...a study among recreational marathon runners reported that 64% of the runners performed stretching after training [122]. Another survey on elite adolescent athletes found that 23% of the Asian and 68% of the UK athletes used stretching after a training session [91]. Finally, a survey among collegiate athletic trainers in the USA found that 61% recommended static stretching to be included as a recovery method after exercise 1. Surveys among coaches from other sports report similar results [2, 3, 5, 137].

If you haven't already tried stretching as a recovery method, I urge you to give it a try.

Answer 3

Answering my own question, since I've had plenty of time to experiment recently:

Immersing yourself in a pool is the fastest option, since the thermal conductivity of water is approximately 30x higher than air. Now this doesn't mean you cool down 30 times faster, because your skin is a good insulator and your body also has to pump heat out, but all things considered, water immersion will definitely be faster than relying on air.

As for how long it takes to return to "normal" temperature, given a starting point of being hot to the point of your face being flushed red (about half an hour of running does the trick for me), with water temperature on the order of 25°C, for me it takes about 12-15 minutes to stop sweating. The time here will obviously vary from person to person, but if you chill out long enough to start getting goosebumps, you're probably good. For comparison, without the pool, it takes me a good half hour.

Theoretically, you can optimize your time by maximizing the movement of water over your body while minimizing your own heat generation, so ideally you'd want to park yourself motionless next to a jet of water. In practice, this seems to make little difference and I spent the time doing cool-down stretches and floating on my back with the occasional dip underwater.

Answer 4

A cold pack can be applied to the abdomen, back of the neck, and/or inside of the upper thigh. This is a technique used by first responders to treat hyperthermia. The large surface area of the abdomen, combined with the proximity of the vascular organs of the liver, stomach, and intestine, make it an ideal site for rapid heat transfer. Similarly for the inside upper thigh, due to its high surface area and proximity to the femoral artery and vein. The back of the neck cools blood flowing to the brain.

If you do not have access to a cold pack, finding a shaded area—preferably with air flow—and removing as much clothing as you can (whilst maintaining dignity) can also reduce your temperature significantly. Again, this is a standard in treating hyperthermia. Although evaporative heat loss is low, it can nevertheless provide excellent radiant and convective cooling due to the large surface area exposed.

Finally, ingestion of cold fluid further aids cooling. Again, due to the high humidity, evoporative heat loss is low. However, heat is exchanged between the body and fluid, and what little evaporative cooling is possible can nevertheless be significant.

I hope that helps.