How Sleep Impacts Your Physical And Mental


In this article Dr. Allison Brager discusses the importance of sleep. Even one bad night can lead to reduced cognitive and physical performance.


This article was written by the Momentous team, the leading provider of Informed Sport and NSF Certified for Sport performance nutrition products, which are trusted by pro athletes and teams worldwide.

// A Simple Thing Called Sleep

There are a million and one performance “hacks” that will supposedly give you greater physical output and mental acuity. 

Some are legitimate – like being active in nature – and others – anything sold via late-night TV ads – mere gimmicks. 

But if we were to rank the biggest bang for your lifestyle-enhancing buck, there would be one that’s like Michael Jordan in the NBA – the unanimous MVP. It doesn’t come in a bottle or an overpriced online course, but is available to you today at no cost. It’s simply called sleep.

sleep well

Sleep Expert Dr. Allison Brager

Dr. Allison Brager knows more than most people about sleep science and its application. 

After all, that’s the neuroscientist’s job in the US Army, and something she has used to great effect to push her to multiple CrossFit Games appearances. 

Both populations – serving soldiers and elite athletes – undergo unusually high physical and mental stress loads, whether they’re incurred in the chaos of the battlefield or during the heat of sporting competition.

Due to travel and topsy-turvy schedules, enlisted personnel and world class competitors also face disruption to their sleep schedules, which can knock their circadian rhythms off kilter. 

It’s Allison’s job to help the soldiers she serves and her CrossFit teammates make the most of circumstances that are often suboptimal for sleep, so they can perform at their best when it matters most. 

“What you’re trying to do is get into the slowest form of brain wave activity: slow wave,” Allison said. 

“It’s only during this kind of sleep that you release anabolic hormones and begin all these recovery processes that are absolutely necessary to perform at your best day in and day out.”

A Bad Night Sleeping

Conversely, research demonstrates that even one bad night can seriously impair both physical skills and mental focus. 

On the cognitive side, lack of sleep appears to reduce athletes’ ability to assess their surroundings and select the appropriate motor pattern for the situation. 

An Iranian research duo noted that after a single bad night’s sleep, athletes’ reaction time was considerably slower. In a 2015 review of the literature released via Science, Australian and Swiss scientists wrote that, “numerous studies investigating the effects of sleep loss on cognitive function report slower and less accurate cognitive performance.” 

A seminal study published in the Journal of Human Movement found that athletes who’d slept poorly the night before several different psychomotor tests fared worse than those who were well rested.

 One of the same researchers, Thomas Reilly from Liverpool John Moores University in the UK, noted in a later study that female athletes seemed to be more adversely affected than their male counterparts after inadequate sleep duration. 

In a third paper published in Ergonomics, Reilly and his team concluded that getting three hours of sleep for three nights reduced athletes’ ability in a maximal bench press, leg press, and deadlift. 

The more nights that their sleep was compromised, the more ineffective their weight room efforts became. It’s not just power athletes who are impacted when they get inadequate sleep quantity and/or quality. Shona L. Hanson from the Australian Institute of Sport wrote that, “Sub-maximal, prolonged exercise appears to be more affected by sleep deprivation than short, maximal efforts.”

How To Sleep Better

The good news from Reilly’s 20+ years of sleep studies with athletes? 

A 30-minute early afternoon nap seemed to restore physical output and short-term memory.  So when you’ve had a restless night, try a post-lunch siesta in a cool, dark room so you can perform well in that afternoon practice or evening game.

 Cutting out caffeine at least six hours before bedtime and limiting your alcohol consumption can help your sleep onset. Alcohol and caffeine can interfere with the kind of deep sleep needed to repair your body and ready your mind for action tomorrow. 

“Excitatory and inhibitory chemicals have to work together so you can fall and stay asleep,” Allison said. 

Things To Help You Sleep

sleep well

A further way to modulate this chemical balance is to try a supplement with research-backed ingredients that will promote better nighttime rest. 

Allison and other sleep experts helped us select wild jujube seeds, melatonin, and Magtein®, the only form of relaxation-promoting, stress-busting magnesium demonstrated to cross the blood-brain barrier. 

So if you’ve tried cleaning up your sleep routine, getting a consistent sleep and wake time as much as possible, sleeping in a tech-free bedroom, and still are struggling with your slumber, give Momentous Sleep a try. Your next performance will thank you.



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