title: Heavy-resistance training in older Scandinavian men and women: short- and long-term effects on arm and leg muscles.
abstract: The short- and long-term effects of heavy-resistance training (85% of one-repetition maximum (RM)) on elbow flexion and knee extension dynamic and isokinetic strength and on morphology in the biceps brachii and vastus lateralis muscles were evaluated during 1 year in 35 Scandinavian men and women, aged 70-77 years, 12 of whom formed a control group. After the first 11 weeks of training (n = 23; 3 times/week) elbow flexion and knee extension dynamic strength (1 RM) had increased [mean +/- SD] 49% +/- 16 and 163% +/- 75, respectively, with no significant difference between men and women. For the following 27 weeks, strength was maintained with one training session per week (n = 12) but dropped without training (n = 11). After the final 11 weeks of training (n = 11; 3 times/week), strength had further increased 32% +/- 16 in both the arm and the leg. Isokinetic strength measurements (Cybex II; 30 degrees/s) revealed similar but smaller gains than for dynamic strength. Muscle biopsies (n = 20) taken at the start and after the first 11 weeks of training showed a significant increase in the area of both type 1 and type 2 fibers in the biceps brachii muscle and a positive significant correlation between the percentage increase in the proportional area of type 2 fibers in the vastus lateralis muscle and the percentage increase in knee extension dynamic muscle strength. In conclusion, older Scandinavian men and women have a high capacity both to improve and to maintain muscle strength, some of which is mediated through an adaptation in the muscle fiber type population.
authors.affiliation: Department of Rehabilitation, Lund University Hospital, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Lexell
authors.forename: D Y
authors.initials: DY
authors.lastname: Downham
authors.forename: Y
authors.initials: Y
authors.lastname: Larsson
authors.forename: E
authors.initials: E
authors.lastname: Bruhn
authors.forename: B
authors.initials: B
authors.lastname: Morsing
mesh_terms: D000222:Adaptation, Physiological; D000367:Age Factors; D000368:Aged; D001132:Arm / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology*; D010806:Physical Education and Training / Q000379:methods*; D012737:Sex Factors; D013548:Sweden