Triathletes have to be excellent time managers as they try to juggle jobs and family responsibilities with training. All too many try to pick up additional minutes by cutting down on their sleep. Unfortunately, sleep deprivation sabotages exercise performance. Our bodies are hardwired to operate in the daytime. Studies show that as we begin to develop a sleep deficit, our ability to metabolize sugar is impaired and our blood levels of insulin increase. For a triathlete, this means less energy during the day and ultimately a less effective workout.
A second consequence of sleep deprivation for triathletes is an increase in cortisol levels. Normally, cortisol levels increase while we are sleeping, reaching a peak around 6:00 A.M. Cortisol levels rapidly decline during the daylight hours. When we are sleep deprived, however, cortisol levels remain elevated. Increased levels of cortisol lead to reduced muscle protein synthesis and increased protein degradation, and ultimately poor post-workout recovery.
What does this all mean to the time-challenged triathlete? It is self-defeating to cut down on your sleep. Doing so may give you more time to work out, but it will make your training less effective. You’re better off training a little less yet more effectively by giving yourself the 7.5 hours of sleep you need every night.