Like eating, sleeping is an essential human function, but scientists are not 100 percent sure why we actually need to sleep. What we do know is that sleep is a critical time for recovery, solidifying learning and promoting overall health. I’m sure most of us are familiar with sleep recommendations (8-9 hours for teens and young adults), and we all probably can name a few reasons sleep is important, but today we’ll explore how nutrition and sleep impact each other and why both are so essential for athletes.
How nutrition impacts sleep
While diet and sleep routines are highly individualized, there are some general recommendations for foods to avoid shortly before bed, as they tend to keep us awake. Large meals or meals high in fat before bed can hinder sleep because they take longer to digest. When we are sleeping many bodily functions slow down, and digestion is one of them. If a large meal or fatty meal is sitting in the stomach, it can cause discomfort, nausea or heartburn. To avoid these potential issues, have your last meal or snack two hours before bed.
Spicy foods might cause heartburn or general GI discomfort in some people as well, so it might be prudent to enjoy them at lunch. Finally, avoid caffeine after noon to prevent disruption of sleep at night. Caffeine has a half-life of 5-6 hours, meaning that if you consume a cup of coffee at noon, half of the caffeine remains in your system until 5 or 6 p.m., and the full effects likely are not gone until 10 p.m. or later.
How sleep impacts nutrition
Insufficient sleep has numerous implications for nutrition and overall health, many of which are still being researched today. As Matthew Walker points out in his book “Why We Sleep: Unlocking the Power of Sleep and Dreams,” decreased sleep duration tends to elevate the hormone Ghrelin, which stimulates hunger and tends to decrease the hormone Leptin, which makes us feel full. Sleep also impacts cognitive function and decision making, rendering us more likely to pick a less healthy option if we are sleep-deprived. Sleep-deprived athletes who need to wake up early for school also might be more likely to skip the ever-important breakfast meal if they wake up late, and we know we need this meal to help meet our energy needs and jumpstart our day.
For athletes in particular, sleep is an important part of the recovery process. If we consume all the nutrients necessary for repair and recovery work but we do not give our body the time to do its job, then we might have decreased training responses and could be more injury-prone. Decreased sleep has been shown to reduce muscle protein synthesis and glycogen synthesis, both of which are essential for muscle growth and building energy stores.
Other sleep considerations
Inadequate sleep has been shown to weaken the immune system, which increases the risk of illness. As we have discussed in previous articles, an illness could take an athlete out of practice or competition for several days or more and set back overall training. Decreased sleep also impairs cognitive function, motor skills and focus, which all equate to poor performance and increased injury risk. Finally, as Walker stresses, sleep is the time when our brain solidifies learning (both facts and motor skills), so if you had a tough practice where you learned a new skill or technique, sleep is what ingrains that in our memory.
Improving sleep habits:
- Avoid screens (phone, iPad, TV, computer) before bed, as the light color disrupts sleep onset.
- Keep your room cool.
- Keep your room dark; use curtains or a sleep mask to help.
- Keep calm. If you are often stressed, anxious or high-energy at night, try listening to soothing music or sounds, reading, journaling or meditating/deep breathing to relax the body.
- If you cannot fall asleep, get up (read, listen to quiet music) and try again in 20 minutes.
Sarah Gilbert, MS, RD, LDN, is a registered dietitian with a master’s in nutrition from Boston University. Sarah is the nutrition coach for RPM Athlete Performance and helps athletes optimize performance and wellness and reduce risk of injury through nutrition. For more information, visit rpmathlete.com.
