The science of warming up

A warm-up routine can be critical in increasing preparedness for subsequent effort and thus maximizing performance. However, the effectiveness of the warm-up routine appears to be dependent on many factors such as the type of sport, athlete fitness and experience, tasks to be performed, environmental conditions, and constraints imposed by event organizers. New research on warming up has attempted to quantify those factors, by synthesizing the results of 30 peer-reviewed studies on warming up in team sports.

General comments on warming up

Of the warm-up research reviewed, 69% showed an improvement in sprint performance, 87.5% showed an improvement in jump performance, and 83% showed an improvement in agility performance. This suggests that a properly structured warm-up strategy can increase athlete performance in many different sports. However, comparing results between studies is difficult due to different control groups and different warm-up protocols. Therefore, to define a properly structured warm-up strategy, it is important to know which variables are critical for optimizing subsequent explosive performance. Research tends to recommend a short active warm-up that progresses in intensity until maximal effort close to the end of the warm-up. Shortly afterwards, passive strategies should be implemented before the game and the re-warm-up should include short sprints and jumps before entering the game.

Warming up

The research found that a wide range of warm-up routines showed improvements in performance with a large effect size. For example, 8x50m sprints, a 5min jog with 5RM leg press, or completing back squats at the end of a typical warm-up have been shown to improve subsequent explosive performance. Other research showed that seven minutes of dynamic exercises after 5mins of jogging was associated with general improvement in explosive tasks such as sprinting, jumping and agility performance. Small sided games and whole body vibration may improve explosive task performance.

All this shows that a short specific warm-up is as effective as a long specific warm-up for sprint performance. On the other hand, static stretching was the least effective at improving sprint performance and agility.

Warm up best practices
  • Research suggests a short warm-up (<20min) has the same benefits on performance as a long warm-up (>20min).
  • Warm-ups performed at an intensity too high for too long could result in fatigue and impair subsequent exercise.
  • However, what must be considered is the athlete. Some athletes feel psychologically more prepared after a 25min warm-up than a shorter warm-up regardless of performance decreases.
  • Explosive tasks such as sprints and jumps require a more strenuous warm-up intensity (~90% of Max HR). For example, sprint tasks performed at the end of the warm-up have shown a 2-3% improvement in sprint and jump performance.
  • An optimal strategy may look like this: 10-15min increasing intensity (~50-90% HRmax) ending with sprints.
  • Reducing warm-up time and intensity may delay fatigue and lead to overall higher performance during the match.

Post warm up

Many coaches focus on the warm up and the main training session, but neglect how they are linked. Post warm up strategies can be as essential to performance as the warm up itself. For example, in cases where athletes rest after the warm up, a progressive decrease in performance was observed. This effect ranged from 4-6% decrease in sprint performance to a 12-20% decrease in jump performance.

Another post warm up strategy is to keep athletes warm using a heated garment. This showed a moderate effect on sprint performance. When combined with 3×5 jumps with 20% bodyweight, a large positive effect was observed on sprint performance. No strategy was found to be effective in improving jump performance.

Post warm up best practices
  • After 20mins rest, athletes decreased jump performance by approx. 15%. After 40mins rest, jump performance decreased by approx. 20% and sprint performance by 6%.
  • Standing up 20mins after the warm-up may reduce the decrease in performance compared with sitting on the bench. However, this would depend on the rules of the organisers whether standing is allowed.
  • Passive strategies such as heat garments after warm-up can significantly maintain the benefits gained from the warm-up or at least reduce the decline.
  • Combining a passive strategy with an active one (e.g. 3×5 jumps) has been found to be even more beneficial.

Re warm up

The re-warm up, often taking place after halftime, has different needs and effects than standard warm ups. But there are also some similarities. For example, a decrease in performance was once again identified when passive rest was implemented during the re-warm up. Heat garments had the best effect size compared with resting in sprint and jump performance. Eccentric exercises were the only intervention found to be detrimental to sprint and jump performance.

One difference is that re-warm ups can potentially be lower intensity than what is typically thought. A recent paper showed cycling for 3mins at 30% VO2max was as effective as cycling at 60% VO2max on subsequent intermittent cycling sprint performance after a an initial period of intermittent sprint cycling.

Re warm up best practices
  • Team sport half times are usually between 10-20min. Passive rest of this time has been shown to decrease physical and cognitive performance.
  • Very little research has investigated the effects of different re-warm-up protocols. Of the few studies, 4×5 jumps and 7-8mins of running at ~70% HRmax have been shown to increase subsequent performance.
  • Theoretically, a re-warm-up could consist of a combination of heat maintenance strategies (active and/or passive), hormonal priming (feedback, video clips), caffeine and carbohydrate consumption. These separate strategies have been shown to reduce performance decrements in the second half.
  • While these strategies haven’t been tested together, some sort of heat garment or an active warm-up routine should be performed before subsequent activity.

Factors to consider in putting it together

Team sport warm-ups generally run anywhere from 20 to 40 minutes which sometimes don’t include the athletes individual preparation prior to the team warm-up. Based on this review, it may be more beneficial to shorten the team warm-up to potentially decrease subsequent fatigue and receive the same benefits. However, in sports such as rugby where coaches want to cover unit specific skills, attack and defense, as well as a short dynamic warm-up, it can be very difficult to fit this into such a short time frame of 20 minutes. For some more on this topic, see the discussion on the most recent HMMR Media member hangout.

Additionally, certain players like to be out earlier to do their own individual pre-warm-up or work specific skill sets such as kicking. This study may be an example of what is good in the literature may not be good in a practical setting. However, that does not mean certain points cannot be adapted to the real world. For example, gradually increasing intensity of the warm-up. Potentially a warm-up could start with low intensity skills to get the heart rate up. Following this some more specific unit or team skills could be incorporated that are a little more intense. Following this some kind of offense or defense drill that gets HR closer to 90%. To finish, one or two sprints can be done for some high intensity speed and potentiation.

Finally, the post warm up and re-warm up strategies presented in this study should be implemented with all team sports. However, time available along with environmental conditions must be taken into consideration. You don’t want to put heat garments on players in 30°+ Celsius temperatures. Rather, active strategies are better used in this situation.