Resistance Training Contribute to the Aerobic Components of an Exercise Session in Adults but not as Much in Older Adults

Previous research has indicated that active adults are able to achieve moderate intensity as measured via heart rate during a typical resistance training (RT) session. The main objective was to identify if overweight adults and older adults can reach aerobic moderate intensity at a rate comparable to adults displaying a recommended body mass index. Twenty participants in each group were asked to visit a fitness facility twice if they self-reported doing RT for a minimum two days per week. At the first session baseline characteristics and maximal lifting capacity for each RT exercise. At the second, intensity was monitored via heart rate monitor during a RT exercise program composed of 10 exercises targeting major muscle groups. Three sets of 10 repetitions at 70% of maximal load were completed for each exercise. Moderate intensity was defined as a minimum of 40% of heart rate reserve. The proportion of time spent at moderate to vigorous intensity between the comparison group and the overweight adult group was not significantly different, with a median (25th-75th) proportion time of 82.6% (69.2-94.6) versus 92.5% (73.3-99.1); p=.54 or an average time of 42 minutes versus 45 minutes. The older adults group, however, spent a lower proportion of time at moderate to vigorous intensity compared with the comparison group, 51.5% (22.0-86.6) or 24 minutes; p<.01 compared with the comparison group. This study suggests that a good proportion of time spent doing RT can contribute to an aerobic component of the international guidelines, and therefore reduce the weekly time commitment especially for men and women age below 60 years old.