It is a general assumption, and one informed by the collective experience of athletes around the world, that active people reaching their 40s, 50s, and beyond need more recovery time than they used to. And of all recovery methods and tools, sleep is the primary means of recovery from training stress. It enables the crucial growth and rejuvenation needed in the muscular, skeletal, immune, and nervous systems, among others. In fact, there is nothing else you can do that will help you recover faster or more completely.
Sleep is critical to success in sport and not something to mess around with, yet many choose to shorten their sleep time in order to pack more stuff into their lives. It’s quite common for athletes to stay up late watching their favorite TV shows and then set an alarm so they can get up early the next morning in order to fit in a workout before heading off to work. If you depend on an alarm clock to wake you, then you probably aren’t getting enough sleep—or enough recovery. Going to bed earlier would more than likely improve your performance. That single lifestyle change may even improve your life in other ways.
Several studies have found that the amount of sleep you get is closely associated with not only your health but also your longevity. Short sleep durations have been shown to increase the risk of obesity, heart disease, and type 2 diabetes. Conversely, those who report regularly sleeping six to seven hours per night appear to have long life spans. A naturally occurring sleep duration is probably best for longevity as well as health. Your normal nightly sleep duration is probably determined by genetics and shouldn’t be artificially shortened. It is probably beneficial to wake up naturally rather than to the buzzing of a clock.
Sleep Stages and Hormones
While there is still a lot to be learned about sleep, it appears that each stage has a specific, essential purpose. The two with which we are most concerned are the REM and slow-wave “N3” stages. Most of your recovery occurs in these stages.
REM is the truly high-quality stage of sleep, when most recovery happens. REM is also when you do most of your memorable dreaming. This stage lasts for a few minutes at a time and makes up 20 to 25 percent of your sleep time if you have a full night of sleep. REM happens about every 90 minutes to 2 hours, with another stage, non-rapid-eye movement (NREM), or brief awakenings making up the in-between times. During REM the tissue-building hormones testosterone and estrogen are released into the body to aid recovery. These hormones are categorized as anabolic steroids, meaning that they promote growth and repair of muscles and bones. They also have a positive effect on other cellular properties that improve endurance performance; for example, they help build the capillary network for blood delivery to the muscles.
In terms of recovery, testosterone is the more potent of these two hormones. Men produce about 20 times as much testosterone as women, but women’s bodies are more sensitive to it. Since REM occurs late in a night’s sleep cycle, artificially shortening your sleep by awakening to an alarm clock may well diminish the release of these hormones, thus hindering full recovery. The negative impacts may not be too great after a night or two of lost REM time, but chronically shortening your natural sleep cycle is likely to have a long-term effect on training quality and performance.
The other critical recovery sleep stage is slow wave (N3). It generally starts about an hour after falling asleep and recurs several times during the first half or so of the night. During this time your body experiences a rush of growth hormone (GH) that promotes muscle growth and bone repair. Nearly half of your daily GH secretion occurs during this stage. That’s why pro athletes often take naps—they’re trying to increase their GH production. Short of losing an entire night of sleep, you’re unlikely to miss your daily dose of growth hormone. But since aging reduces the total amount of growth hormone your body produces, you can’t afford to miss any sleep at all.
Unfortunately, slow-wave sleep duration is shortened in older folks, as we tend to wake up more often. In college-aged youth, slow-wave sleep makes up about 19 percent of sleep time. For older folks, it’s more like 3 percent. That makes for a huge reduction in recovery-enhancing GH. Combine that with reduced testosterone production due to low-quality REM sleep and using an alarm clock to wake up, and it’s no wonder your fitness and performance are going south.
Overall, with aging there is a tendency for an earlier onset of sleep in the evening, an earlier morning awakening, and more-fragmented and shallower sleep throughout the night. This further decreases the release of the anabolic hormones testosterone and GH. Unfortunately, cortisol, another hormone largely unchanged with age, is released into the bloodstream while we sleep. Cortisol’s primary function is to prepare the body to cope with stress by increasing blood sugar while also compromising the immune system. It’s also been shown to slow the healing of injuries and decrease bone formation.
Improving Your Sleep
Despite the double whammy of the hormone issues, sleep is very definitely the key to better performance with aging. To help maximize sleep time, there are a few things you can do that may prove beneficial besides wearing blue-blocking glasses in the evening, which may make you feel a bit weird. There are some common ones:
- Avoid caffeine in the late afternoon
- Don’t work out intensely in the four hours or so before bedtime
- Maintain a calm and quiet environment before going to bed
- Follow a regular sleep schedule
- Bed down in a dark and cool room
Go light on alcohol in the evening, as it has a rebound effect that can wake you later from an otherwise sound sleep. While alcohol doesn’t seem to negatively affect slow-wave sleep and may even be beneficial for it, it has been shown to reduce REM sleep duration.
Some athletes take a melatonin supplement in the evening to promote drowsiness. I don’t recommend it because typically when a supplement is used to promote some functional change, the body responds by reducing or even halting its own, natural production of the targeted product while possibly becoming less sensitive to it.
An alternative solution that some studies have reported is drinking a glass of tart cherry juice in the evening. I know that sounds strange, but it seems to work. The aging subjects in these cherry-juice studies had an increase in melatonin production and improved sleep compared with a placebo. Again, weird—but possibly beneficial.
Timing Your Meal
The hour when you eat your evening meal and what it is made up of may also affect your nighttime sleeping. As your mom told you when you were a kid (of course, you didn’t pay any attention), a late-evening meal or large pre-bedtime snack can reduce sleep quality, so don’t chow down right before going to bed.
One study has shown that the foods you eat late in the day may affect how well you sleep. University of North Dakota researchers looked at which types of food were most likely to improve your sleep and, conversely, which may have negative consequences. Forty-four adult subjects ate either a high-protein, a high-fat, a high-carbohydrate, or a balanced control diet before retiring for the evening. They did this over a four-day period and crossed over so that each subject ate all of the four meal types. They went to bed at a regular time after each of the meals, and their sleep quality was measured. The fewest sleep interruptions came after the high-protein meal. The high-carb meals produced the least-restful sleep.
So the bottom line is that it may be advantageous for your subsequent sleep, especially if you typically don’t sleep well, to eat a little additional protein rather than more carbohydrate for supper or a pre-bedtime snack.
I want to once again emphasize that sleep is the single most important thing you can do to speed your recovery. It will complement your high-quality training while helping you avoid setbacks due to injury, illness, and overtraining. If you artificially shorten your sleep by using an alarm clock to wake up, then you simply aren’t snoozing enough.
If you don’t sleep well—meaning that your sleep is interrupted by long periods of being awake—or you don’t sleep at least six hours per night, then you need to take corrective steps. Without adequate sleep, anything else that you do in training will have a greatly reduced benefit simply because your recovery will always be lacking.
Adapted from Fast After 50: How to Race Strong for the Rest of Your Life by Joe Friel with permission of VeloPress.