The study found that athletes' performance peaks at different times of day depending on whether they are naturally early risers or night owls. Early risers peaked in the early afternoon, while night owls reached their peak performance in the evening. This suggests that tailoring training and competition schedules to an individual athlete's circadian rhythm could help maximize their performance. However, more research is needed to prove that changing sleep-wake cycles can enhance athletic performance.

1. Early Birds May Catch the Worm, but Night Owls May
Snatch the Win
THURSDAY, Jan. 29, 2015 (HealthDay News) -- Who's going to win Sunday's Super Bowl? It may
depend, in part, on which team has the most "night owls," a new study suggests.
The study found that athletes' performance throughout a given day can range widely depending on
whether they're naturally early or late risers.
The night owls -- who typically woke up around 10 a.m. -- reached their athletic peak at night, while
earlier risers were at their best in the early- to mid-afternoon, the researchers said.
The findings, published Jan. 29 in the journal Current Biology, might sound logical. But past studies,
in various sports, have suggested that athletes usually perform best in the evening. What those
studies didn't account for, according to the researchers behind the new study, was athletes'
"circadian phenotype" -- a fancy term for distinguishing morning larks from night owls.
These new findings could have "many practical implications," said study co-author Roland
Brandstaetter, a senior lecturer at the University of Birmingham, in England.
For one, athletes might be able to maximize their competitiveness by changing their sleep habits to
fit their training or play schedules, he suggested.
"What athlete would say no, if they were given a way to increase their performance without the need
for any pharmaceuticals?" Brandstaetter said. "All athletes have to follow specific regimes for their
fitness, health, diet and psychology."
Paying attention to the "body clock," he added, just adds another layer to those regimens.
The study began with 121 young adults involved in competitive-level sports who all kept detailed
diaries on their sleep/wake schedules, meals, training times and other daily habits.
From that group, the researchers picked 20 athletes -- average age 20 -- with comparable fitness
levels, all in the same sport: field hockey. One-quarter of the study participants were naturally early
birds, getting to bed by 11 p.m. and rising at 7 a.m.; one-quarter were more owlish, getting to bed
later and rising around 10 a.m.; and half were somewhere in between -- typically waking around 8
a.m.
The athletes then took a series of fitness tests, at six different points over the course of the day.
Overall, the researchers found, early risers typically hit their peak around noon. The 8 a.m. crowd,
meanwhile, peaked a bit later, in mid-afternoon.

2. The late risers took the longest to reach their top performance -- not getting there till about 8 p.m.
They also had the biggest variation in how well they performed across the day.
"Their whole physiology seems to be 'phase shifted' to a later time, as compared to the other two
groups," Brandstaetter said.
That includes a difference in the late risers' cortisol fluctuations, he said. Cortisol is a hormone that,
among other things, plays a role in muscle function.
But while the study showed clear differences in the three groups' peak-performance times, it didn't
prove that trying to change an athlete's natural sleep/wake tendencies will boost performance.
"You can't infer that from this study," said Dr. Safwan Badr, immediate past president of the
American Academy of Sleep Medicine.
To prove that would work, he said, researchers would have to do an "intervention" study where they
recruited night owls or early birds and changed their sleep/wake cycles.
Plus, altering one's body clock would be easier said than done, according to Badr. It could also get
complicated, he noted, for athletes who have to travel to different time zones to compete.
"If you're an East Coast team playing on the West Coast at night, you're really at a disadvantage,"
Badr said.
In fact, a 2013 study of National Football League teams found that since 1970, West Coast teams
have had a major advantage over East Coast teams during night games.
Sunday's Super Bowl will be played at 6:30 p.m. EST in Glendale, Arizona -- which would seem to put
the New England Patriots at a disadvantage against the Seattle Seahawks. Still, based on the new
findings, the outcome might partly depend on the proportion of night owls on each team.
Brandstaetter acknowledged that this study does not prove that changing athletes' body clocks
improves their performance. But it's a question his team is actively investigating.
For an elite athlete, any change that could enhance performance even a little could make a big
difference, since seconds can separate medal winners from losers, Brandstaetter noted.

3. "The most important thing to consider here," he said, "is that just getting up at a certain time on the
day of the competition will not help if this time is different from internal biological time."
Most people, of course, aren't elite athletes. But Badr said it could be worthwhile for everyday
exercisers to consider the time of day when they feel they're at their best.
"That might help you enjoy physical activity more," he said.
But when it comes to sleep, Badr said the most important thing -- for all of us -- is to get enough of it.
SOURCES: Roland Brandstaetter, Ph.D., senior lecturer, school of biosciences, University of
Birmingham, England; Safwan Badr, M.D., immediate past president, American Academy of Sleep
Medicine, chief, pulmonary, critical care and sleep medicine, Wayne State University School of
Medicine, Detroit; Jan. 29, 2015, Current Biology
http://www.nlm.nih.gov/medlineplus/news/fullstory_150678.html