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Updated: Jul 16, 2026
Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People
Published on: July 5, 2017
Alpha-actinin-3 (ACTN3) R577X polymorphism influences knee extensor peak power response to strength training in older
Matthew J Delmonico1, Matthew C Kostek, Neil A Doldo
1Department of Kinesiology, University of Maryland, College Park, MD 20742, USA.
Background:
The alpha-actinin-3 (ACTN3) R577X polymorphism has been associated with muscle power performance in cross-sectional studies.
Methods:
We examined baseline knee extensor concentric peak power (PP) and PP change with approximately 10 weeks of unilateral knee extensor strength training (ST) using air-powered resistance machines in 71 older men (65 [standard deviation = 8] years) and 86 older women (64 [standard deviation = 9] years).
Results:
At baseline in women, the XX genotype group had an absolute (same resistance) PP that was higher than the RR (p =.005) and RX genotype groups (p =.02). The women XX group also had a relative (70% of one-repetition maximum [1-RM]) PP that was higher than that in the RR (p =.002) and RX groups (p =.008). No differences in baseline absolute or relative PP were observed between ACTN3 genotype groups in men. In men, absolute PP change with ST in the RR (n = 16) group approached a significantly higher value than in the XX group (n = 9; p =.07). In women, relative PP change with ST in the RR group (n = 16) was higher than in the XX group (n = 17; p =.02).
Conclusions:
The results indicate that the ACTN3 R577X polymorphism influences the response of quadriceps muscle power to ST in older adults.
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