Physical activity at age 11 years and chronic disabling fatigue at ages 13 and 16 years in a UK birth cohort.
OBJECTIVE
To investigate associations of physical activity at age 11 years with chronic disabling fatigue (CDF) at ages 13 and 16 years.


DESIGN
Longitudinal birth cohort.


SETTING
South-West England.


PARTICIPANTS
Adolescents enrolled in the Avon Longitudinal Study of Parents and Children.


OUTCOMES AND EXPOSURES
We identified adolescents who had disabling fatigue of >6 months' duration without a known cause at ages 13 and 16 years. Total and moderate-to-vigorous physical activity and sedentary time at age 11 years were measured by accelerometry over a 7-day period.


RESULTS
A total physical activity level 100 counts/min higher at age 11 years was associated with 25% lower odds of CDF at age 13 years (OR=0.75 (95% CI 0.59 to 0.95)), a 1% increase in the proportion of monitored time spent in moderate-to-vigorous activity was associated with 16% lower odds of CDF (OR=0.84 (95% CI 0.69 to 1.01)) and a 1-hour increase in sedentary time was associated with 35% higher odds of CDF (OR=1.35 (95% CI 1.02 to 1.79)). Disabling fatigue of only 3-5 months' duration at age 13 years had weaker associations with physical activity, and CDF at age 16 years was not associated with physical activity at age 11 years.


CONCLUSIONS
Children who had chronic disabling fatigue at age 13 years had lower levels of total and moderate-to-vigorous physical activity and more sedentary time 2 years previously, but this association could be explained by reverse causation.
['Collin|Simon M|SM|', 'Norris|Tom|T|', 'Deere|Kevin C|KC|', 'Jago|Russell|R|', 'Ness|Andy R|AR|', 'Crawley|Esther|E|']
D061725:Accelerometry D000293:Adolescent D002648:Child D015444:Exercise D015673:Fatigue Syndrome, Chronic D006801:Humans D008137:Longitudinal Studies D011446:Prospective Studies D012307:Risk Factors D057185:Sedentary Behavior D006113:United Kingdom
physical activity ALSPAC adolescent health chronic fatigue syndrome