Stay Warm After Warm-Up for Hot Performances

Introduction

It is well known in sports science that warm-ups that increase muscle temperature also improve power output in high power events lasting less than 5 minutes of so. Indeed, there is about a 4% increase in vertical jump power for every degree centigrade increase in muscle temperature. In cycling, peak power output improves up to 10% for every degree centigrade increase in a muscle’s temperature.

Warm-ups of high enough intensity can increase muscle temperature by 3-4 degrees C.  However, we usually warm-up then sit and wait for an event to start so that benefit of warmed up muscles drops as our muscle temp drops. However, what if we keep the muscles warm and prevent that drop by wearing (hot!) pants with heating elements in them to keep the muscle temp elevated to the level we had after the warm-up?

Here is a British study (yep, those brits love their cycling research!) aimed to determine the effect of passive insulation versus external heating during recovery after a sprint-specific warm-up on thigh muscle temperature and subsequent maximal sprint cycling performance.

The Research

On three separate occasions separated by three days, 11 male cyclists (24.7 ± 4.2 years old, 1.82 ± 0.72 m tall, 77.9 ± 9.8 kg) completed a standardized 15-min warm-up (5 min cycling at 100 watts then 5 x 10 second sprints separated by 1 min 50 sec of pedaling at 75 watts) on a cycle ergometer. The warm-up was followed by a 30-min passive recovery period before completing a 30-second all-out sprint test on a bike. Muscle temperature was measured in the thigh muscle (vastus lateralis) at 1, 2, and 3 cm depth before and after the warm-up and immediately before the sprint test. Absolute and relative (/kg) peak power output (watts) was determined and blood lactate concentration was measured immediately after exercise. During the 30 minute recovery period, participants wore a tracksuit top and either (i) standard tracksuit pants (CONT), (ii) insulated athletic pants (INS), or (iii) insulated athletic pants with integrated electric heating elements (HEAT). The heating element covered the back and front of the thigh but not the middle of the legs and was like a small electric blanket that was heated to 40-42 degrees C.

The Results

Warm-up increased muscle tempaterature by approximately 2.5 °C at all muscle depths, with no differences between the three conditions. During recovery, muscle temperature remained much more elevated in HEAT compared with INS and CONT at all depths. Power output (watts/kg) in the 30-second sprint was elevated by 9.1% in HEAT (20.9 ± 1.6 w/kg) compared with CONT (19.2 ± 1.7 w/kg). The increase in blood lactate concentration was also significantly greater after sprint in HEAT (6.3 ± 1.8 mmol/L) but not INS (4.0 ± 1.8 mmol/L) versus CONT (4.1 ± 1.9 mmol/L).

The research team concluded that passive heating of the thighs between warm-up completion and sprint cycling using pants incorporating electrically heated pads can lower the decline in muscle temperature and improve sprint cycling performance.

The So What?

The results of this study highlight how important it is to keep the specific muscles involved with sport as warm as possible after warm-up until the event we are doing starts. We can do this by staying active right up to the start of the event, wearing warm gear up to the event, or using heaters or heat pads (blankets) to keep the muscles warm. This study supports other previous studies that show this works in high power events lasting up to about 5 minutes in duration.

In longer endurance events where high power outputs aren’t as critical, the same principles also apply but aren’t as important if we can build into the event once it starts. However, where positioning is critical in endurance events (eg open water swim events, triathlon, cycling) when powerful starts are important, there are some lessons to be learnt from this research. Stay as warm as pssible up to the start of your event.

For more on warming up smart as an older athlete, see Chapter 4 (Principles of Training the Masters Athlete). Now avialable as a stand-alone pdf chapter along with 18 other chapters in the only book I’ve ever seen that brings the science of sport to athletes over 35 years of age.

Source: Faulkner, S. and others (2013) Reducing muscle temperature drop after warm-up improves sprint cycling performance. Medicine and Science in Sports and Exercise, 45(2): 359-365.