Reproducibility and changes in twitch properties associated with age and resistance training in young and elderly women.

We compared knee extensor twitch contractile properties (TP) between nine young women (YW, 20-30 years) and 10 elderly women (63-78 years) and examined changes associated with resistance training in addition to measurement reproducibility. Data were obtained on two occasions 3 weeks apart after which subjects performed bilateral leg extension and bilateral leg curl exercises 3 days/week for 10 weeks. TP demonstrated moderate to good reproducibility in both age groups with Pearson's r and the intra-class correlation coefficient ranging from 0.

Comparative effects of resistance training on peak isometric torque, muscle hypertrophy, voluntary activation and surface EMG between young and elderly women.

We compared the effect of a 10-week resistance training program on peak isometric torque, muscle hypertrophy, voluntary activation and electromyogram signal amplitude (EMG) of the knee extensors between young and elderly women. Nine young women (YW; range 20-30 years) and eight elderly women (EW; 64-78 years) performed three sets of ten repetitions at 75% 1 repetition maximum for the bilateral leg extension and bilateral leg curl 3 days per week for 10 weeks. Peak isometric torque, EMG and voluntary activation were assessed before, during, and after the training period, while knee extensor lean muscle cross-sectional area (LCSA) and lean muscle volume (LMV) were assessed before and after the training period only.

Normalized lengthening peak torque is associated with temporal twitch characteristics in elderly women but not young women.

Aim: To determine if greater normalized torque during maximal effort lengthening actions in elderly women compared with young women is related to age-associated adjustments in neural activation and/or contractile function.

Methods: The right knee extensors of 14 young women (21-30 years) and 12 elderly women (65-78 years) were assessed for isometric, shortening and lengthening peak torque, electromyography (EMG) activity, and isometric twitch contractile properties. Knee extensor contractile tissue volume was determined using magnetic resonance imaging.

Chronic exercise and skeletal muscle power in older men.

We sought to determine the effects of age and chronic exercise on muscle power in older males. We examined 32 older males 60-74 years of age and grouped as sedentary (CON, n = 11), chronic endurance trained (ET, n = 10), and chronic endurance trained + resistance training (ET + RT, n = 11). Exercise history was obtained by questionnaire.

Endurance exercise and leg strength in older women.

Quadriceps strength and mass peak in the third decade of life, plateau, and then decline from the fifth decade on. To examine the influence of chronic endurance training and age on lean mass and leg strength, women runners (n = 62, age 43-69 years) and sedentary participants (n = 33, age 43-66 years) were divided into 40-, 50-, and 60-year age groups. Absolute isokinetic concentric torque did not differ between runners and sedentary women (97.