A brand-new study on sleep and the hitting performance of professional baseball players asks a really important and vastly under-studied question: do athletes who are morning people vs. evening people perform differently depending on the time of day? The new study was recently presented at the Sleep 2011 conference by lead author Dr. W. Christopher Winter, medical director of the Martha Jefferson Hospital Sleep Medicine Center in Charlottesville, Va. Via Medical News Today:
Results indicate that players who were “morning types” had a higher batting average (.267) than players who were “evening types” (.259) in early games that started before 2 p.m. However, evening types had a higher batting average (.261) than morning types (.252) in mid-day games that started between 2 p.m. and 7:59 p.m. This advantage for evening types persisted and was strongest in late games that began at 8 p.m. or later, when evening types had a .306 batting average and morning types maintained a .252 average…..
The study used the players’ statistics from the 2009 and 2010 seasons, which allowed for the analysis of 2,149 innings from early games, 4,550 innings from mid-day games and 750 innings from late games. Game start times were adjusted for travel using the principle that for every time zone crossed, it takes 24 hours to adjust.
“These results are important as they create an entirely new way to look at athletic talent,” said Winter. “Currently, selecting a player for a game situation usually involves factors such as handedness, rest, and possibly previous success against a certain team. Now, the time of day in which the game is occurring and a player’s chronotype might be a wise factor to take into account.”
The sample size in the study was not large enough to prove statistical significance, so it’s important not to try to take too much from the results. The study raises more questions than it answers, but the questions are good and important ones. The differences between “morning people” and “evening people” are real; sleep scientists have known this for a long time. They show markedly different patterns in their circadian rhythms, the 24-hour cycles that help govern our sleep-wake cycles. Over the course of these cycles a whole host of variables wax and wane: the levels of various hormones, core body temperature, activity in certain brain regions, and alertness and reaction time. It seems that the ability to effectively hit a baseball might be another one of those variables that changes throughout the day.
If the results of this study turn out to hold up as significant in larger samples it could introduce a whole new element to pre-game preparation, and make an athlete’s preference for morning or evening an essential piece of information. There are ways to influence the circadian rhythm. For example, light boxes that emit very bright, white light work by suppressing the hormone melatonin and can push the circadian rhythm back, effectively making someone more of an “evening person”, temporarily. Such therapies are used to combat jet lag or sleep disorders, but it is easy to see the potential use for helping morning baseball players perform better in a night game.
Above all, the research is a great example of the questions that are being asked about human performance that will change sports dramatically in the coming years. It’s no longer just about the body as a hunk of muscle, tendon and bone. Athletic performance is more complicated. It’s about the brain; it’s about sleep and hormonal cycles; it’s about the mind and psychology. It all needs to be integrated.