Concurrent improvements in cardiorespiratory and muscle fitness in response to total body recumbent stepping in humans

Abstract.

A group of 26 sedentary adults [mean age 48.4 (SD 6.4) years] were allocated randomly into either a non-exercising control group (CON, n=9) or an exercise group (EX, n=17) that trained 3 days a week for 12 weeks using a total body recumbent stepper (TBRS). Training intensity and duration progressed from 50% of heart rate reserve maximum (HRR_max) for 20 min to 75% HRR_max for 40 min. Maximal exercise responses were measured during incremental treadmill (TM) and TBRS tests to examine the specificity of the adaptations to training. Muscle strength was measured using a one repetition maximum (1 RM) test for the leg press (LP), chest press (CP), and seated row (SR). Muscle endurance (END) was evaluated for LP, CP, and SR as the number of repetitions achieved before failure when exercising at an intensity of 60% of baseline 1 RM. Body composition was estimated using the sum of seven skinfolds. After training, significant increases (P<0.05) in maximal oxygen uptake and exercise time were observed in the EX group on both the TM (9.3% and 4.8%, respectively) and TBRS (18.2% and 70.5%, respectively). The TBRS training resulted in significant increases (P<0.01) in 1 RM and END of the legs, chest, and back, with greater magnitude of improvements observed for END. Furthermore, TBRS training resulted in a significant increase in lean body mass and significant reductions in fat mass and percentage body fat (P<0.01). The CON did not show changes in any measurement (P>0.05). These data indicated concurrent improvements in both cardiovascular and muscle fitness. The greater improvements observed on the TBRS test and in muscle endurance suggest the adaptations are specific to the mode of training.