Throughout the day, as a result of normal metabolism, adenosine accumulates in our brain, increasing sleepiness. Caffeine reduces sleepiness by competitively inhibiting adenosine receptors.
Sleep has a profound impact on the health of the entire body. Various supplements have been shown to have positive impacts on sleep.
Getting enough sleep is crucial for maintaining brain health, reducing the risk for neurodegenerative and cardiovascular disease, bolstering the immune system, sustaining good mental health, and recovering from the stressors of the day. The American Academy of Sleep Medicine and Sleep Research Society recommends that adults (over 18 years of age) should get at least 7 hours of sleep per night. Sleep deprivation is associated with obesity, and this relationship may be due to changes in eating, activity levels and hormone levels.
Changes in an individual’s dietary pattern can impact their sleep architecture. A meta-analysis found that high carbohydrate intake increases rapid-eye movement (REM) sleep, whereas low carbohydrate intake increases non-rapid-eye movement (non-REM sleep). Also, some observational studies have found an association between increased healthy food (e.g. fruits, vegetables, fiber, seafood, and whole grains) intake and improved sleep quality. In essence, consuming a balanced and nutrient-rich diet may help to optimize sleep.
The supplements of most interest are apigenin (the active ingredient in chamomile), California poppy, cannabidiol, hops, passionflower, kava, lavender, magnesium, melatonin, and valerian. However, it is best to consult a healthcare provider before consuming any sleep supplement because they may interact with prescription medications.
Supplement GuideClick here to read the Sleep Supplement Guide
While there is a general consensus that exercising in the morning or afternoon benefits sleep, it’s often recommended to avoid exercising, especially at a high intensity, in the evening in fear of it negatively affecting sleep.
However, according to a meta-analysis published in 2021, an acute bout of high-intensity exercise performed 2–4 hours before bedtime does not disrupt sleep. In fact, performing high-intensity exercise 2 hours before bedtime tends to increase total sleep time (+16 minutes) and decrease the time it takes to fall asleep (−5 minutes). However, longer duration high-intensity exercise (>30–60 minutes) may decrease rapid-eye movement sleep to a small extent (−3%).
In a 7-week study in elite youth soccer players, an evening high-intensity exercise session did not affect sleep quality and slightly increased sleepiness at bedtime, compared to nights where no exercise was performed.
In sum, high-intensity evening exercise does not appear to negatively affect sleep. Careful consideration should be given to pre-workout supplements when exercising in the evening, as products containing caffeine can negatively affect sleep.