EXERCISE, SUBSTRATE UTILIZATION AND ENERGY-REQUIREMENTS IN THE ELDERLY

We consider the impact of endurance and resistance exercise on energy expenditure and substrate utilization in the elderly, We present data to show that endurance exercise increases resting metabolic rate in el derly men and women and these changes appear to be sympathetically med iated, Preliminary data also shows that vigorous endurance exercise ca uses a compensatory decline in energy expenditure during the non-exerc ising portion of the day, suggesting that this type of exercise prescr iption may actually be counter-productive to promoting fat loss, Sever al studies using resistance training interventions in older individual s suggests that this exercise mode also increases resting metabolic ra te and basal sympathetic nervous system activity, The impact of age an d endurance exercise on fat mobilization and oxidation are briefly con sidered, The major findings are that whole body fat oxidation decrease d with advancing age and this decrease was primarily related to the ag e-associated decrease in fat-free mass, Furthermore, endurance trainin g altered basal utilization patterns in the elderly by shifting dispos al of fatty acids from nonoxidative to oxidative pathways and that inc reases in fat oxidation were related to the increase in norepinephrine appearance rate. Exercise interventions that preserve fat-free mass a nd/or enhance aerobic capacity may increase or maintain fat oxidation and possibly blunt the tendency towards increasing adiposity in older individuals.