How Much Does Heat Slow You Down Running

When it comes to running, the impact of heat on performance can be significant. As a passionate runner, I’ve experienced firsthand how much the heat can slow me down and affect my overall performance. Let’s delve into the details of just how much heat can impact running and what measures can be taken to mitigate its effects.

The Impact of Heat on Running

Running in hot weather can lead to a range of physiological challenges. The body’s core temperature rises more rapidly, causing increased sweating as the body attempts to cool down. This excess sweating can result in dehydration, leading to decreased blood volume and increased heart rate. As a result, the cardiovascular system has to work harder to deliver oxygen to the working muscles, ultimately leading to a decrease in performance.

Furthermore, the heat can also affect the body’s ability to regulate its internal temperature, potentially leading to heat-related illnesses such as heat exhaustion or heat stroke. These conditions can be not only detrimental to performance but also dangerous to overall health.

Scientific Studies

Various scientific studies have been conducted to assess the impact of heat on running performance. One study published in the Medicine & Science in Sports & Exercise journal found that for every 10-degree rise in temperature above 55°F (12.8°C), performance times in a 5K race could be slowed by approximately 1.5%. Another study in the Journal of Science and Medicine in Sport noted that for every 1°C increase in environmental temperature above 15°C, 5K performance times were slowed by approximately 6 seconds.

Personal Experience

As someone who loves running, I’ve noticed a significant difference in my performance during hot weather compared to cooler conditions. My pace tends to slow down, and the effort feels exponentially greater. In some cases, I’ve had to cut my runs short due to the intense heat, which can be incredibly frustrating.

Mitigating the Effects

While it’s clear that heat can have a substantial impact on running, there are measures that can be taken to mitigate its effects. Staying hydrated before, during, and after runs is crucial. Wearing appropriate moisture-wicking clothing and considering early morning or late evening runs when temperatures are cooler can also help minimize the impact of heat.


In conclusion, the impact of heat on running performance is undeniable. From physiological challenges to decreased performance times, the heat can significantly slow you down as a runner. By being mindful of these effects and taking proactive measures to combat them, it’s possible to minimize the impact of heat on running performance. Whether it’s adjusting the timing of runs or staying properly hydrated, understanding and addressing the impact of heat is crucial for any runner aiming to perform at their best.