The aging process, along with the lifestyle, is associated with loses in functional capacity and independence due to factors such as decreases in muscle mass, strength, and aerobic capacity, among others. Resistance training (RT) has been shown to induce strength and muscle size gains in the elderly. Improvements in maximal endurance capacity have been shown in some studies, while others have found no change. The purpose of the present study was to examine the effects of RT on the cycling economy in the elderly.
A group of 47 older men and women (65-75 years) participated in the study. Subjects were assigned into one of two groups: 1) a training group performing 3 months of RT focusing on local muscular endurance followed by 6 months of RT focusing on maximal strength and hypertrophy, or 2) a non-training control group. Maximal strength (dynamic leg press), submaximal endurance capacity (incremental cycling test), HR at rest, and Hb and Hct were determined before the intervention (
PRE), after 3 months (MID) and after 9 months (POST). Cycling economy (CE) was determined as the average oxygen consumption of the last two minutes of each stage and VO2peak was estimated through the extrapolation of the estimated HRmax from the linear regression analysis of HR and VO2 values. All subjects were instructed to record their physical activity levels in diaries.
The main findings were significant improvements in CE in all four groups at MID and POST compared to PRE (except Int W during stage 4). HR response during the cycling test was reduced during stage 2 in the women’s groups, during stage 3 in all groups and during stage 4 in both men and women of the intervention groups and men of the control group. Blood La concentrations were only reduced in the training groups. No significant differences between groups were observed for VO2, HR or La. The results also showed significant increases at MID and POST in 1RM dynamic leg press (MID, Int M, 7%, p<0.05, Int W, 13%, p<0.05; POST, Int M, 15%, p<0.01, Int W, 20%, p<0.05) and estimated VO2peak (MID, Int M, 13%, p<0.05, Int W, 7%, p<0.05; POST, Int M, 11%, p<0.01, Int W, 10%, p<0.05) in the intervention group only. Relative changes in estimated VO2peak were not significantly different when compared to the control group. No significant changes occurred in HRrest, Hb and Hct in either the intervention or control groups. From PRE to MID the control group tended to perform more endurance exercise when compared to the intervention group (p=0.068), which may have led to the observed improvements in CE.
In conclusion, this study showed that a RT protocol focusing on local muscular endurance led to cycling economy improvements as well as increases in estimated VO2peak and 1RM. This type of RT might be an efficient method to enhance both endurance and strength performance in the elderly during short-term training.
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