Abstract des Autors

This study examined the effect of training on physical activity and substrate utilization in the elderly. Before the start, in week 6 and week 12 (T0, T6 and T12) data on physical fitness, physical activity and substrate utilization were collected in the exercise (11 males, 11 females; 63+/-8 yrs) and control group (6 males, 5 females; 59+/-4 yrs). Physical activity was registered with a tri-axial accelerometer and substrate utilization was calculated from resting respiratory exchange ratio (RER) by indirect calorimetry. At T6 physical activity on training days was significantly higher than on non-training days (33.4+/-10.3 vs. 26.5+/-7.8 counts/min; p<0.001). At T12, after adjusting for training activity, physical activity on training days was significantly lower than on non-training days (23.7+/-8.4 vs. 28.2+/-9.3 counts/min; p<0.01). RER decreased significantly (0.02+/-0.03; p<0.05), indicating a relatively larger fat oxidation. Changes in RER were negatively correlated with pre-training RER. In conclusion, in elderly an increase in structured training (exercise) is compensated for by a corresponding decrease in non-training physical activity. Training increased relative fat utilization in elderly with a high pre-training RER, whereas elderly with a low pre-training RER decreased their relative fat utilization. Verf.-Referat