Muscular fitness in relation to physical activity and television viewing among young adults.
OBJECTIVE
To study how time spent in physical activity and that in television (TV) viewing are associated with muscular fitness among young adults.


METHODS
The study population consisted of a cross-sectional sample of 381 males and 493 females aged 19.1 yr (SD 0.3) from the Northern Finland Birth Cohort 1986. Muscular fitness was measured by trunk muscle strength tests (trunk extension, flexion, and rotation) and jumping height test. Time spent on moderate- to vigorous-intensity physical activity and on TV viewing was self-reported by a questionnaire.


RESULTS
The most physically active young adults performed significantly better in most trunk muscle strength tests and the jumping test than the least active subjects. The mean difference between the most and least active groups was at minimum 1.6 kg (95% confidence interval (CI) = -0.5 to 3.7) and at maximum 10.6 kg (95% CI = 4.7-16.5) for different trunk muscle strength tests and at minimum 4.4 cm (95% CI = 2.7-6.1) for the jumping height test. Males and females who watched TV for >or=2 h x d(-1) performed significantly worse in trunk extension and flexion tests and females also performed worse in the jumping test compared with those who watched TV <2 h x d(-1), independent of their physical activity level. The mean difference between low and high TV users was at minimum -3.8 kg (95% CI = -6.7 to -0.9) for trunk extension and flexion strength and -1.2 cm (95% CI = -2.0 to -0.4) for jumping height in females.


CONCLUSIONS
Among young adults, daily TV viewing for >or=2 h, irrespective of physical activity level, was associated with poorer muscular fitness.
Paalanne
Niko P
NP
Department of Physical and Rehabilitation Medicine, Institute of Clinical Sciences, University of Oulu, Oulu, Finland.
Korpelainen
Raija I
RI
Taimela
Simo P
SP
Auvinen
Juha P
JP
Tammelin
Tuija H
TH
Hietikko
Teiju M
TM
Kaikkonen
Hannu S
HS
Kaikkonen
Kaisu M
KM
Karppinen
Jaro I
JI
D000293:Adolescent; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D009043:Motor Activity; D018482:Muscle, Skeletal / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D057185:Sedentary Behavior; D011795:Surveys and Questionnaires; D013690:Television; D055815:Young Adult