The effects of regular strength training on telomere length in human skeletal muscle.
OBJECTIVE
The length of DNA telomeres is an important parameter of the proliferative potential of tissues. A recent study has reported abnormally short telomeres in skeletal muscle of athletes with exercise-associated fatigue. This important report raises the question of whether long-term practice of sports might have deleterious effects on muscle telomeres. Therefore, we aimed to compare telomere length of a group of power lifters (PL; N = 7) who trained for 8 +/- 3 yr against that of a group of healthy, active subjects (C; N = 7) with no history of strength training.


METHODS
Muscle biopsies were taken from the vastus lateralis, and the mean and minimum telomeric restriction fragments (TRF) (telomere length) were determined, using the Southern blot protocol previously used for the analysis of skeletal muscle.


RESULTS
There was no abnormal shortening of telomeres in PL. On the contrary, the mean (P = 0.07) and the minimum (P = 0.09) TRF lengths in PL tended to be higher than in C. In PL, the minimum TRF length was inversely correlated to the individual records in squat (r = -0.86; P = 0.01) and deadlift (r = -0.88; P = 0.01).


CONCLUSIONS
These results show for the first time that long-term training is not associated with an abnormal shortening of skeletal muscle telomere length. Although the minimum telomere length in PL remains within normal physiological ranges, a heavier load put on the muscles means a shorter minimum TRF length in skeletal muscle.
Kadi
Fawzi
F
Department of Health Sciences, Orebro University, Orebro, Sweden. Fawzi.Kadi@hi.oru.se
Ponsot
Elodie
E
Piehl-Aulin
Karin
K
Mackey
Abigail
A
Kjaer
Michael
M
Oskarsson
Eva
E
Holm
Lars
L
D000328:Adult; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D032496:Satellite Cells, Skeletal Muscle; D019098:Telomerase; D016615:Telomere; D035321:Telomeric Repeat Binding Protein 1; D014891:Weight Lifting / Q000502:physiology*; D016474:Weight-Bearing
D035321:Telomeric Repeat Binding Protein 1; D019098:Telomerase