Can passive warm-up tools enhance exercise performance?

Yes. When used deliberately and in conjunction with an active warm up.

It is especially relevant if the time between the end of the active warm up and the start of the exercise performance (transition phase) is longer than 15 minutes.

We consider this topic as part of a comprehensive paper called Warm-Up Strategies for Sport and Exercise: Mechanisms and Applications by C. Mcgowan et al. It appeared in Sports Medicine in 2015.

The paper reviews the available research to identify potential physiological mechanisms that under pin warm-ups and how they can affect the subsequent performance. The paper also provides recommendations for warm-up strategy design for specific individual and team sports.

The team conducted a systematic search of published studies that examined passive and active warm up strategies. Studies considering performance with a well-defined end point (e.g. a cycling time trial or a 100m swim) were included whereas those studies using time to exhaustion tasks were not.

Unlike an active warm up, a passive approach can increase core or muscle temperature without depleting energy stores.

The use of passive warm-up strategies on their own is not common. However, the idea of using passive strategies is gaining the most traction during transition. Especially when that transition is elongated. In these scenarios heat maintenance, using passive techniques, can help limit the loss of core or muscle temperature.

Muscle temperature starts to decline immediately after exercise. With a significant reduction occurring 15-20 minutes after exercise stops. Transition times are usually fixed and the athlete has little opportunity to influence them. By adding a passive element to a warm up strategy it becomes possible to combat heat lost during this transition phase.

Hot Showers – in swimming competition

The use of hot showers or baths (47C) lasting 8-10 mins were linked to subsequent improvements in performances over 50, 200 and 400 meters.

Baths – in a cycling test

Hot water immersion combined with electric blankets then applied to the lower body increased power output (by 22%) in a 6 sec maximal cycling sprint task.

Heated Garments – in cycling

Heated tracksuit pants worn during a 30 minute transition resulted in a substantial improvement in muscle temperature and a ~ 9% enhancement in both peak and relative power during a sprint test

Blizzard Survival Jackets – in rugby   

An active warm-up followed by the use of a blizzard survival jacket worn during a 15 minute transition phase (to simulate a representative time period at the start of a match) produced faster repeat sprint performance versus control (6.96 +/- 0.14s compared to 7.01 +/- 0.16s).

Further research is welcome to understand the optimum conditions of use including temperature, duration, garment selection and when in the competitive timeline the passive strategy might be used in different sports.

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