For pre- and post-cooling most commonly cooling vests are used. Since these are heavy, bulky and not aerodynamic, they are not useable DURING endurance exercise.
Today the main usage of cooling DURING exercise consist of:
- Using arm-sleeves for sun/UV protection. They offer protection against the sun and when made wet, give some additional evaporation cooling (the same as making a tri-suit/shirt wet), for a short period in time, because these materials dry very quickly. This does not contribute to reducing core-temperature effectively.
- Neck cooling ice packs, they can be useful, but most of the time they are not practical in use during endurance training and races because these are bulky or prevent your neck from moving freely, so not practical during exercise.
- Sponges with water, water from bottles/bidons, spraying water over ones head, are all cooling techniques that should be considered as cooling sensation rather then techniques that really decrease the core temperature (the contact time of the cold water with the body is simply to short).
- Ice-cubes are placed in tri-suits, or placed under a head-cap, or placed in a plastic bag/sock in the upper back/neck area. In a tri-suit the ice-cubes tend to end in the lower back or the crotch area and have limited effect there. Cooling of the head helps to keep the cognitive function more stable, but as seen earlier, this does not really help to decrease core temperature. Next to that, ice that is placed directly on the skin hurts, is uncomfortable (causes headache) and can lead to burning the skin.
- The Omius head-band is used by triathletes and marathon runners, but investigation shows that this product:
1) does not improve heart rate
2) does not improve forehead and rectal temperatures
3) does not improve perceived exertion
4) surprisingly, the OMIUS headband did also not increase whole-body and forehead thermal comfort and performance. So the OMIUS head-band did not even contribute to perception of thermal comfort. See also chapter 5:
So, until recently, there were no real practical cooling products available that do not limit the athlete’s movement and also contribute to decreasing the athletes core temperature DURING endurance exercise effectively.