To determine the differences between arm and leg muscle quality (MQ) across the adult life span in men and women, concentric (Con) and eccentric (Ecc) peak torque (PT) were measured in 703 subjects (364 men and 339 women, age range 19-93 yr) and appendicular skeletal muscle mass (MM) was determined in the arm and leg in a subgroup of 502 of these subjects (224 men and 278 women). Regression analysis showed that MQ, defined as PT per unit of MM, was significantly higher in the arm ( approximately 30%) than in the leg across age in both genders (P < 0.01). Arm and leg MQ declined at a similar rate with age in men, whereas leg MQ declined approximately 20% more than arm MQ with increasing age in women (P

Background: Falls in older people have been characterized extensively in the literature, however little has been reported regarding falls in middle-aged and younger adults. The objective of this paper is to describe the perceived cause, environmental influences and resultant injuries of falls in 1497 young (20-45 years), middle-aged (46-65 years) and older (> 65 years) men and women from the Baltimore Longitudinal Study on Aging.

These results demonstrate that changes in 1 RM strength in response to both ST and detraining are affected by age. However, ST-induced increases in muscular strength appear to be maintained equally well in young and older men and women during 12 wk of detraining and are maintained above baseline levels even after 31 wk of detraining in young men, young women, and older men.

Skeletal muscle satellite cell proportions and morphology were assessed in healthy, sedentary young and older men and women in response to heavy resistance strength training (HRST). Fourteen young (20-30 years) men (n = 7) and women (n = 7) and 15 older (65-75 years) men (n = 8) and women (n = 7) completed 9 weeks of unilateral knee extension exercise training 3 days per week. Muscle biopsies were obtained from each vastus lateralis before and after training, with the nondominant leg serving as an untrained control. All four groups demonstrated a significant increase in satellite cell proportion in response to HRST (2.3 +/- 0.4% vs 3.1 +/- 0.4% for all subjects combined, before and after training, respectively; p < .05), with older women demonstrating the greatest increase (p < .05). Morphology data indicated a significant increase in the proportion of active satellite cells in after-training muscle samples compared with before-training samples and with control leg samples (31% vs 6% and 7%, respectively; p < .05). The present results indicate that the proportion of satellite cells is increased after HRST in young and older men and women, with an exaggerated response in older women. Furthermore, the proportion of satellite cells that appear morphologically active is increased as a result of HRST.

This study assessed ultrastructural muscle damage in young (20-30 yr old) vs. older (65-75 yr old) men after heavy-resistance strength training (HRST). Seven young and eight older subjects completed 9 wk of unilateral leg extension HRST. Five sets of 5-20 repetitions were performed 3 days/wk with variable resistance designed to subject the muscle to near-maximal loads during every repetition. Biopsies were taken from the vastus lateralis of both legs, and muscle damage was quantified via electron microscopy. Training resulted in a 27% strength increase in both groups (P < 0.05). In biopsies before training in the trained leg and in all biopsies from untrained leg, 0-3% of muscle fibers exhibited muscle damage in both groups (P = not significant). After HRST, 7 and 6% of fibers in the trained leg exhibited damage in the young and older men, respectively (P < 0.05, no significant group differences). Myofibrillar damage was primarily focal, confined to one to two sarcomeres. Young and older men appear to exhibit similar levels of muscle damage at baseline and after chronic HRST.

We studied the clinical characteristics of transient global amnesia (TGA) in 277 patients with an average follow-up of 80 months. The syndrome occurred most frequently after age 50. There was a history of migraine in 14.1% and cerebrovascular diseases in 11.2% of patients, but these conditions were usually not temporally linked to TGA. Characteristic antecedent events and activity such as exertion existed in 33.4%. The incidence of TGA was 5.2 per 100,000 per year in Rochester, MN. Although 23.8% of the patients had recurrent episodes, they were not at increased risk for subsequent stroke.

Muscle mass and strength losses during aging may be associated with declining levels of serum testosterone (T) in men. Few studies have shown a direct relationship between T and muscle mass and strength. Subjects were 262 men, aged 24-90 yr, from the Baltimore Longitudinal Study of Aging, who had T and sex hormone-binding globulin sex hormone-binding globulin (SHBG) measurements, from which the free T index (FTI) was calculated (T/SHBG) from serum samples collected longitudinally since 1963, total body fat mass and arm and leg fat-free mass (FFM) by dual-energy X-ray absorptiometry and arm and leg strength by dynanomometry. Mixed-effects models estimated T and FTI at the time of mass and strength measurements. Age, total body fat, arm and leg FFM, T, and FTI were significantly associated with concentric and eccentric strength. FTI, not T, was modestly, but directly, related to arm and leg strength after fat, arm and leg FFM, height, and age were accounted for and indirectly through body mass. FTI is a better predictor of arm and leg strength than T in aging men.

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