Effects of 14 weeks of progressive endurance training on energy expenditure in elderly people

Effects of progressive endurance training on energy expenditure (EE) were s tudied in thirteen elderly sedentary subjects (62.8 (SD 2.3) years) after 7 and 14 weeks of training. Daily EE (DEE) and energy cost of the various us ual activities were measured over 48 h by whole-body indirect calorimetry. Free-living DEE (DEEFLC) was calculated from 7 d activity recordings and th e energy costs of activities were measured in the calorimeters using the fa ctorial method. DEEFLC did not vary significantly throughout the training p eriod despite the additional energy cost of training sessions (0.60 (SD 0.1 5) MJ/d), because energy expended during free-living activities (EEACT) dec reased by 4.8 (SD 7.1) % (P < 0.05) and 7.7 (SD 8.6) % (P < 0.01) after 7 a nd 14 weeks of training respectively. Measurements in the calorimeters show ed that sleeping metabolic rate transiently increased by 4.6 (SD 3.2) % aft er 7 weeks of training (P < 0.001) and returned to its initial level after 14 weeks of training. BMR was 7.6 (SD 7.0) % (P < 0.01) and 4.1 (SD 6.1) % (P = NS) higher after 7 and 14 weeks of training respectively, than before training. Likewise, diet-induced thermogenesis increased from 3.7 (SD 2.5) to 7.2 (SD 2.8) % energy intake after 7 weeks of training (P < 0.05), and r eturned to its initial level after 14 weeks of training (4.2 (SD 2.6) % ene rgy intake). Despite these changes, energy expended during activities and t he corresponding DEE did not vary throughout the training period. It was co ncluded that: (1) DEEFLC remained constant throughout the training period d ue to a compensatory decrease in free-living EEACT; (2) progressive enduran ce training induced a transient increase in sleeping metabolic rate, BMR an d diet-induced thermogenesis after 7 weeks which was not reflected in the e nergy expended during activities and DEE.