Better sleep seen as new target in sports nutrition
Jaime Tartar, PhD, spoke at the recent meeting of the International Society of Sports Nutrition in Clearwater Beach, FL. Tartar, who is a professor of psychology and neuroscience at Nova Southeastern University in Ft. Lauderdale, FL, admitted her talk was an odd fit at a conference heavy on studies seeking ways to boost muscle protein synthesis. And Tartar herself cut an anomalous, sylphlike figure in a room filled with men and women who are obviously seeking to maximize their muscle mass.
The psychological aspects of sports performance
“I study the neurobiology of stress. I do studies on stress and sleep. How did I get here?” she said.
“A while ago I started looking at what are the positive changes in the brain when you exercise,” she offered by way of answer.
Tartar laid out a picture for how cortisol, often called the ‘stress hormone,’ functions in the body’s flight or fight stress response system.
Cortisol floods into the blood stream from the adrenal gland when this stress response is triggered, and helps speed glucose uptake into muscle cells, up regulates blood pressure and regulates other functions to enable the body to operate at a peak, albeit unsustainable, level that enabled our ancestors to fight off predators.
As with so many other biochemical processes in the body, such as inflammation, having the right amount for the right time is the key. Several diseases are associated with improper cortisol levels; in Cushing’s syndrome there is too much, while in Addison’s disease there is too little.
So, just as with inflammation, just telling consumers you are going to quench their cortisol levels doesn't make sense, Tartar said. But controlling it, making sure that this hormone is circulating only when its supposed to, does. Like other inflammatory markers, chronic, elevated levels of cortisol are an indication of damage occurring, Tartar said.
“Disregulated cortisol is associated with impaired memory, immune system impairments, weight gain, high blood pressure, etc.” she said.
“Cortisol is more associated with psychological stress,” Tartar said. So having a physically stressful job, like doing road construction, wouldn’t necessarily be associated with elevated levels. But being a trial lawyer might.
Sports combines many aspects of stress response
Sports performance activities uniquely combine the two. There are the physical stressors of tissue damage associated with extreme level performance, and the psychological stress of winning or losing, worrying about how the coaches or fans are judging your performance, etc.
“Cortisol is not a hormone you want to decrease per se,” Tartar said. “It is part of a closed system.”
But if the regulation of cortisol levels is not accessible directly, how can formulators, coaches, nutritionists, etc., help clients and consumers manage its manifestation?
Tartar suggested that working to improve clients sleep could be one of the holy grails of sports nutrition. While BCAAs, whey protein isolates and what have you all have their place, maybe just boosting sleep could go further than other interventions, and more naturally, too.
“Getting better sleep is one of the easiest thing you could do to increase performance. People who sleep fewer than six hours a night have fewer REM (rapid eye movement) sleep cycles. Poor sleep hygiene is associated with problems like weight gain. REM sleep is when you have muscle memory consolidation, so it boost the effect of training. And sleep works to flush toxins from the brain,” she said.
