A. Young

Effects of Resistance Training on Strength, Power, and Selected Functional Abilities of Women Aged 75 and Older

OBJECTIVE: To determine the effects of 12 weeks of progressive resistance strength training on the isometric strength, explosive power, and selected functional abilities of healthy women aged 75 and over.

Changes in the albumin binding of tryptophan during postoperative recovery : A possible link with central fatigue?

Tryptophan is the precursor of the neurotransmitter 5-hydroxytryptamine (5-HT), known to be involved in sleep and fatigue. In the blood, tryptophan binds to albumin, and that which does not, free tryptophan, competes with branched chain amino acids (BCAA) for entry into the brain. The plasma concentrations of albumin, free tryptophan, total tryptophan, and BCAA were measured before and after major surgery in nine elderly and nine coronary artery bypass graft (CABG) patients. In both the elderly and the CABG patients plasma free tryptophan concentrations were increased after surgery, compared with baseline levels; the plasma free tryptophan/BCAA concentration ratio was also increased significantly after surgery. Plasma albumin concentrations were decreased significantly after surgery in both the elderly and the CABG patients. Plasma BCAA concentrations were not affected by surgery in either group. The effect of exercising to exhaustion on 5-HT and tryptophan were investigated in Nagase analbuminemic rats (NAR). The intrasynaptosomal concentration of tryptophan, 5-hydroxy-tryptophan, and 5-HT was increased by fatigue after exercise. In addition, running time to exhaustion was shortened in NAR. These data suggest that free tryptophan uptake and 5-HT synthesis were enhanced in the nerve terminal. A decrease in plasma albumin may account for the increase in plasma-free tryptophan levels. An increase in plasma free tryptophan, resulting in an enhanced plasma concentration ratio of free tryptophan/BCAA, may lead to a higher 5-HT concentration in some parts of the brain and, consequently, to central fatigue. It is suggested that provision of BCAA as a dietary supplement may counteract the increase in plasma free tryptophan and thus improve the status of some patients after major surgery.

A Study of Force and Cross‐Sectional Area of Adductor Pollicis Muscle in Female Hip Fracture Patients

OBJECTIVES: To determine the extent of muscle weakness in older female hip fracture patients compared with healthy older and young women; to determine the extent to which this weakness is caused by a decline of the force produced per unit area of muscle rather than by a decline in muscle bulk; and to investigate the mechanism of the decline in force per unit area.

Muscle function of women aged 65–89 years meeting two sets of health criteria

This study compared the isometric strength, leg extensor power, and some potentially related functional abilities of elderly women selected for exercise studies according to two sets of readily applicable exclusion criteria. The health status criteria (“healthy” and “medically stable”) differed principally in respect to duration of freedom from diagnosed or symptomatic disease, medication taken and Body Mass Index. Fifty “healthy” women and fifty “medically stable” women, aged 65 to 89 and evenly distributed over the age range, were recruited through local and national newspapers. There was no significant difference between the two health groups in strength or power. However, the women in the “medically stable” group were heavier and had more difficulty in rising from a chair. The strength of the relationships between strength, power and kneel rise time were very dependent on body weight for the “medically stable” women but not for the “healthy” women. The health criteria used to classify elderly subjects must be clearly specified so that there may be easier interpretation of results from future studies. This is especially true in studies where body weight might be important.