Evidence
of disturbed sleep and increased illness in overreached endurance athletes

Hausswirth
C, Louis J, Aubry A, Bonnet G, Duffield R, Le Meur Y. Med & Science in Sports & Exercise. 2013 Sept 24 [Epub
ahead of print]

Take Home Message:
Overreaching endurance athletes may be more likely to develop abnormal sleep
quality and quantity as well as upper respiratory infections.

Many
endurance athletes increase their training volume or intensity as an attempt to
improve their physical performance. However, inadequate recovery can cause a
short-term abnormal training response called “overreaching,” which potentially
results in a decline in sleep quantity and quality and subsequently a higher risk
of upper respiratory tract infections. Hausswirth and colleagues examined endurance
athletes to determine if they experience abnormal sleep quantity and quality after
they experience overreaching in response to an overload training program.
Secondly, the authors tested if reduced sleep quality would be accompanied with
higher incidence of upper respiratory tract infections among these athletes.
Twenty-seven experienced male triathletes were randomly assigned to an overload
training group (18 athletes) or a normal (control) training group (9 athletes).
Training programs included a 1-week moderate training phase, followed by a
3-week period of overload training for the overload group or normal training
for the control group, and then a subsequent 2-week taper. During the overload
phase, the overload group trained at a 30% higher rate than their normal
training load, while the control group continued their normal habitual
training. Mood states (measured by the Profile of Mood States
questionnaire) and upper respiratory tract illness symptoms and
gastrointestinal discomfort were collected in every phase. The authors
determined sleep quality every night of the six-week period by using wristwatch
actigraphy. Nine of the
eighteen athletes in the overload group were diagnosed as functionally
overreached. During the overload phase, the functionally-overreached group
demonstrated a decrease in sleep duration, sleep efficiency, and immobile time
(time spent not moving while sleeping). These athletes improved in all three
outcomes during the taper phase. Athletes who functionally overreached reported
more upper respiratory tract infections during the overload and tapering phases
(67%) compared with the control group (11%). 

This
study indicated that triathletes who functionally overreach during periods of
high-volume training experienced sleep disturbances and an increased incidence
of upper respiratory tract illness. Perhaps if we educate coaches and athletes
about these risks we can prevent overreaching, decrease illnesses, and increase
sleep quality and quantity among our athletes. All of which are incredibly
important for an athlete who is in the middle of training for competition. Adequate
amounts of sleep are important for athletes because it is a crucial recovery
time for the body and their performance suffers when they are exhausted.
Clinicians should also take into consideration the fact that a decrease in
sleep efficiency could negatively impact an athlete’s personal life (e.g.,
school, work). This could increase the athlete’s stress level, which could also
impair their athletic performance. Impaired performance could lead an athlete
to think they need to train harder, causing a viscous cycle of these effects. During
this study, the reported illness symptoms and sleep disturbances peaked during
the last week of the overload period, which could imply an accumulative effect.
This would occur mostly during pre-season and mid-season because the athletes
are conditioning and focusing on working toward their maximum competition
level. If an athlete complains about their sleeping habits it could be
interpreted as a reaction to overreaching while training. If we can recognize
overreaching early this may allow us to alter their training regimen, possibly
preventing the development of illness. The findings in this study support
previous studies that reported that immunity is depressed during sustained
periods of heavy training. This association suggests there is a link between
the recuperative processes of sleep and the immune system. Therefore, we need
to be aware of reported sleep disturbances and how the risk of overreaching may
negatively affect an athlete’s competition.

Discussion Questions:
Have you noticed a decrease in sleep quality and quantity and/or an increase of
illness in athletes who are overreaching? Why do you think overreaching causes
a decrease in sleep quality and quantity? This study focused on endurance
athletes; do you think the same reactions would occur in sprint athletes?

Written
By: Sara Dorsten
Reviewed
By: Lisa Chinn and Jeffrey Driban

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Hausswirth C, Louis J, Aubry A, Bonnet G, Duffield R, & Le Meur Y (2013). Evidence of Disturbed Sleep and Increased Illness in Overreached Endurance Athletes. Medicine and Science in Sports and Exercise PMID: 24091995