What are the benefits of half-time re-warm up?

The benefits of warming up prior to physical activity is well-established. The purpose of warming up is to prepare the body for the upcoming activity, in order to optimize performance. From a physiological standpoint, a warm up is an important factor in “waking up” the body. Several physiological mechanisms take place, where some of the most important are increased breathing volume and rate, increased stroke volume and dilation of blood vessels, in order to transport more oxygen to meet the metabolic demand of the working muscles. All these processes are improved by increased body temperature from a gradual warm-up.

The general warm-up routine in football consists of 20-30 minutes of low- to high-intensity exercises. This physical preparation elevates muscle and body temperature, an important factor for physical performance. Studies from football has shown a relationship between increased muscle temperature and enhanced sprint performance (1), which highlights the importance of warm-up for maximal efforts at the start of match.

It has been shown in football that distance covered in high-intensity running (> 14.4km×h-1) is reduced during the first 15min period of the 2nd half compared to the first 15min period of the 1st half (2). This might seem odd as one could expect the half-time to provide enough rest for players to perform maximally at the start of the 2nd half. There could be several explanation for this phenomen, but a plausible physiological explanation could be reduced body temperature. Studies have shown that both muscle- and core temperature was significantly reduced during half-time when players were passively seated, and that reduced body temperature was related to a drop in physical performance at the start of the 2nd half (1).

Hence, the question is therefore if a re-warm up during the half-time break can maintain body temperature, and increase the physical performance at the start of the 2nd half?

Repeated sprint ability

It has been shown that a re-warm up during the half-time break resulted in unchanged muscle- and core temperature for amateur players, compared to before the half-time break (1). The players rested for 7min, and used the rest of the half-time break to re-warm up at moderate intensity (at 70% of maximal heart rate). As a result of the half time re-warm up, these players were able to preserve repeated sprint ability at the same level as before the game, and before the half-time break.

Maximal sprint performance

Illustration only

A recent study (3) from an elite team in Sweden supports the findings of the benefits of a re-warm up. The researchers investigated the difference between a passive and active half-time break, were the active group used 7-8min of the half-time to re-warm up at moderate intensity. The results showed that the team performing a warm up during the break, maintained 10m sprint performance, while the passive group had a drop in sprint performance.

Heart rate and oxygen uptake

In addition to this, the Swedish study found that the team with a half-time re-warm up, started the 2nd half with higher heart rate levels, and were able to reach mean 2nd half heart rate values faster than the passive group (3). This indicates that players are able to reach a higher oxygen uptake faster, as heart rate and oxygen uptake has a near linear relationship. An early and apt oxygen uptake (oxygen kinetics) will recruit the aerobic energy system faster, therefore using less anaerobic metabolism early in the 2nd half to meet the metabolic demand. This has in previous research shown to relate with the ability to maintain repeated sprint ability in football (4).

Summary

There seems to be good evidence that a re-warm up towards the end of the half-time can contribute to preserve physical performance in the first part of the 2nd half. The ability to perform maximally and repeat such actions is an important factor for a modern football player, and a re-warm up regime during the half-time can prepare players to maintain these actions from the 1st half.

It could also be that reduced body temperature from a passive half-time can affect the risk of injuries. A warm-up prior to physical activity contributes to increased muscle- and core temperature, that optimizes the activation of muscles and makes them more flexible, at the same time as tendons become more elastic and can withstand a greater load. Since football is a sport with several different movement patterns at high speed, muscles that are at a optimal temperature should be able to perform maximally. Hence, it could be that a half-time re-warm up also could contribute to reduce the risk of injuries.

A re-warm up during the half-time should consist of football-specific movement patterns, like straight-line running, turns, jumps, acceleration and deceleration, in order to simulate football activity. Based on the research published, this should benefit football players at all levels to perform optimally at the start of the 2nd half.

 

Refernces
  1. Mohr M, Krustrup P, Nybo L, Nielsen JJ, Bangsbo J. Muscle temperature and sprint performance during soccer matches–beneficial effect of re-warm-up at half-time. Scandinavian journal of medicine & science in sports. 2004;14(3):156-62.
  2. Bradley PS, Sheldon W, Wooster B, Olsen P, Boanas P, Krustrup P. High-intensity running in English FA Premier League soccer matches. Journal of sports sciences. 2009;27(2):159-68.
  3. Edholm P, Krustrup P, Randers MB. Half-time re-warm up increases performance capacity in male elite soccer players. Scandinavian journal of medicine & science in sports. 2014.
  4. Dupont G, McCall A, Prieur F, Millet GP, Berthoin S. Faster oxygen uptake kinetics during recovery is related to better repeated sprinting ability. European journal of applied physiology. 2010;110(3):627-34.

Leave a Reply

Your email address will not be published. Required fields are marked *