You may be aware that before a bout of exercise, you should spend some time warming up. But why do fitness professionals keep harping on about this?

Anecdotally, it seems we don’t think about this much when we’re younger. We treat warm-ups as a waste of time and wave away anyone who reminds us they’re important. Many people skimp on their warm-ups. I’m certainly guilty of it. However, there appears to come a stage in life, after which even considering exercising without a warm-up feels painful. We feel stiff and stuck and know that we couldn’t dream of working out without easing into it slowly and gradually.

Really, warm-ups are important for us all. But why? What’s so special about them?

In short, warming up helps improve our training performance by increasing body and muscle temperature, enhancing metabolism, improving muscle fibre function, increasing oxygen uptake, improving neuromuscular performance, and enhancing psychological readiness (McGowan et al., 2015).

Let’s break it all down.

Benefits of Warming Up

This is by no means an exhaustive list, but the following are some of the main benefits of warming up before a training session. If you’d like to read about this in more detail, you can check out the paper by McGowan et al. (2015), which I’ve linked in the references section below. This article closely follows the section of that paper I found most relevant, and therefore, all credit for the points listed below should go to the authors.

1. Temperature mechanisms

This may seem quite obvious to you. Warming up, by definition means that there is an increase in temperature in the muscle. But have you ever stopped to consider why this increase in temperature is beneficial?

For starters, it increases muscle metabolism. What this means is that chemical reactions in the muscle can occur at a quicker rate, improving the performance of the muscle in athletic tasks. This increase in temperature also increases the utilisation of substrates by the muscle fibres that are used for muscle contraction to occur.

Additionally, an increase in temperature results in higher power output by the muscle and faster relaxation of the muscle after force production. These factors are important for producing high forces in a short period of time in sprint and power sports.

2. Metabolic mechanisms

When a short bout (about 6 minutes) of heavy-intensity exercise is performed as a warm-up, followed by 9-10 minutes of recovery, this can increase one’s initial oxygen uptake (VO₂) during a subsequent bout of exercise. This oxygen uptake is needed for efficient aerobic energy production, limiting the use of anaerobic stores of energy that may be needed later on in the exercise session.

This kind of warm-up also reduces the delayed increase in oxygen use during prolonged exercise, which is often linked to fatigue or inefficient muscle use, known as the VO₂ slow component.

Moderate-intensity warm-ups will not increase oxygen uptake efficiency in the same way, while warming up with severe-intensity exercise has been found to be beneficial in some contexts and detrimental in others. What seems to be clear is that exercise performance may suffer if the transition period between the warm-up and the subsequent exercise bout isn’t long enough (i.e. at least 9 minutes long). This is because it takes time for muscle homeostasis to return (e.g. lactate clearance). With that being said, transition periods should not be much longer than 10 minutes, as the beneficial warming and priming effects of the warm-up might wear off.

3. Neural Mechanisms

An active warm-up with sufficient loading, often results in something called potentiation. This means that the nervous system is turned on or awakened and can better and more quickly react to subsequent exercise demands.

Post-activation potentiation is when muscle performance is improved following almost maximal or maximal neuromuscular activation. Therefore, if maximal voluntary contractions are produced beforehand, this can increase subsequent power output and improve performance. This could occur through increased calcium sensitivity, improved neuromuscular activation and/or increased cross-bridge cycling among other mechanisms.

While there is a lot of evidence for maximal voluntary contractions improving post-activation potentiation, these warm-up exercises may not be practical in a competition situation. As a result, ballistic-style pre-loading activities like drop jumps, which can also improve power output, have gained popularity more recently.

One important thing to keep in mind with potentiating warm-up exercises is that a balance must be stricken between potentiation and fatigue. It is critical that the warm-up does not fatigue one to the extent that it hampers later power production and exercise performance. Relatively higher loads are required for potentiation during warm-up, but it is important that a sufficiently-long transition phase is observed to allow for adequate recovery. The optimal load appears to be a moderate 60-84% of maximum, as this avoids detrimental muscle damage that higher loads would cause. Potentiating exercises should be followed a by 7-10-minute transition for experienced athletes as this duration appears to be optimal, however, there is individual variation and each athlete should assess what the optimal transition time is for them.

4. Psychological mechanisms

Aside from physiological priming, a warm-up can also help to mentally prepare an athlete for competition and performance. It’s a time during which they can focus on the task at hand and begin to use other psychological techniques like visualisation and positive self-talk to psych themselves up or calm themselves down as needed, to motivate themselves, increase their confidence and subsequently improve their performance.

Keep in mind…

With warm-ups it is important to keep in mind that in environments of high heat and humidity, we must remain vigilant. It may not be wise to design long or intense warm-ups in these conditions as they may result in adverse reactions due to the heat. In these contexts, cooling strategies may be employed to mitigate the risk of these events occurring (McGowan et al., 2015).

Conclusion

Hopefully, this article has made it clear how important warm-ups can be for your subsequent training, as well as how important it is to do your warm-up the right way. If all you’re doing is a 5-minute jog and going straight into your main training block, you may not be getting the most out of your warm-up, and it may be time to change it up.

I hope you now feel inspired to add a 6-7-minute high-intensity warm-up to your session, followed by a 9-10-minute break before athletic training and assess whether this helps your performance. Let me know how it goes in the comments section below!

Reference

McGowan, C. J., Pyne, D. B., Thompson, K. G., & Rattray, B. (2015). Warm-Up Strategies for Sport and Exercise: Mechanisms and Applications. Sports Medicine, 45(11), 1523–1546. https://doi.org/10.1007/s40279-015-0376-x