As would be expected during resistance training, the participants improved their muscle strength, but the participants taking creatine improved just as much as participants receiving the placebo. Creatine did not enhance gains in muscle performance outcomes.
Despite an increase in strength, the participants didn’t improve their lean body mass and even gained some fat mass during the study, perhaps a result of an (unintentional) decrease in protein intake and an increase in fat intake. Notably, the participants’ habitual diets were low in creatine—they consumed between 0.25 and 0.39 grams per day even though they reported eating an omnivorous diet.
Creatine as a sleep supplement?
We could choose to focus on several outcomes here including the lack of an effect of creatine on muscle strength or lean body mass, but I don’t think that’s the unique or applicable finding.
Rather, we should focus on the implications of the interaction between sleep, training, and creatine. Overall, taking creatine did not improve sleep, but I’m not aware of any reason why creatine would improve sleep in adults who are currently sleeping enough. It’s not really a sleep supplement per se.
However, creatine may become a sleep supplement under certain conditions, particularly those involving a significant cognitive or physiological stress. For example, when creatine is taken before sleep deprivation, it improves cognitive performance, enhances brain energy levels, and reduces fatigue the next day.
Even though the participants in this study weren’t sleep deprived, they were exposed to a novel physiological stress—resistance training. None of the participants in this study had resistance training experience, so the addition of 60–90 minutes of training was a significant stimulus for them. This stress appeared to be enough to slightly disrupt their sleep on workout days—an effect that was prevented by taking 5 grams of creatine per day.
The difference in sleep was statistically significant but is also practically relevant—50 minutes is a huge difference in sleep; it's the difference between a restful night and a totally inadequate one. If we think about this in the context of training, getting more sleep on the days you train is going to help you adapt better and improve rapidly. It’ll also reduce your risk of injury, fatigue, and burnout.
Think about it this way: the participants gained an extra 2 hours per week of sleep (1 extra hour on each workout day) simply by taking creatine. If you're working out 3-5 days per week or more, this sleep improvement could be massive if these findings translate to your unique scenario!
Final thoughts
These results might have you wondering if you should only take creatine on the days you workout. The answer to that is no—you should take it every day to experience the benefits (I addressed this question in my recent member-only Q&A session).
However, the benefits of creatine might only be apparent on days that you workout (or are exposed to another stress like a lack of sleep).
Consider taking creatine as a hedge against stress—the stress of life, exercise, intense cognitive work, or sleep deprivation—which we all experience from time to time. As the evidence continues to accumulate on creatine, it’s apparent that nearly everyone should be taking it to support general health. There’s little downside and seemingly unlimited upside.
My recommendation (and what I do) is to take 5 grams per day. This dose is sufficient to saturate your body’s stores after about one month. Larger people may want to increase their dose to 10 grams per day.
If you want to learn more on the brain health benefits of creatine, check out my recent Q&A episode.
