Should you cool down for a perf at 15-20°C outdoor?


Spontaneously, the answer to this title seems obvious… and negative. What’s the idea of cooling down rather than warming up, especially if it’s not hot? Moreover, it is uncommon to observe athletes employ cooling strategies when the temperature does not exceed 25°C. But this sometimes happens… Because it is in this individuality that the necessity – or lack of necessity – to use such interventions seems to rest. Explanations.


Cooling down… A necessity in a temperate environment? The answer will mainly be expressed in regards of performance, since the health component is not specifically exposed at these temperature levels (15-25°C). But if you lack performance benchmarks to objectify the usefulness of refreshing yourself by running at 20°C, other simple indicators can help you decide:

  • the colour of your urine before the race,
  • early and abundant sweating during sessions performed at medium temperature,
  • a pre-post training weighing showing sweat rate >1.5L per hour,
  • a systematic thirst during effort even if it’s not hot,
  • an intolerable feeling of heat despite sweaty clothing,
  • heart rate and thermal discomfort (hot feeling, redness, headaches, etc.) unusually high during exercise…

These are all indicators of potential dehydration – a performance factor since it is assumed that a 2% decrease in body weight (or 3% loss of total body water) is associated with a 10% decline in performance.

Beyond that, without even having to care about these symptoms, you can also simply opt for a cold jacket, a refreshing drink (5 to 15°C), a damp towel on the neck or forehead, etc… if you like. Quite simply! Indeed, the pleasant perception of the material must be sufficient to convince you, since this perception alone is a factor of performance. In other words, feeling is already better running (thanks to the brain and its sensory-motor connections!). So, even if you think you’re already quite comfortable when the temperatures are mild, try and… see if you adopt!


On ambiguous problems such as these, where the answer seems tricky to resolve, an individual approach often gives the solution. Indeed, when a factor x fully expresses itself on the organism (heat, altitude, slope , etc.), there is no debate: the strategy is in fact necessary. But when this factor expresses itself halfway (as it is the case in a temperate environment), it is more in the body’s personal response that the truth is found.

And to encourage you to test the content of this article, think that on semi and marathon, athletes above 41°C internal temperature can achieve performances comparable to those at 39°C. In other words, for similar times, the physiological differences of each one remind us that it can be interesting to favour certain strategies such as cooling, even if it is not hot…