The purpose of this study was to evaluate whether movement speed, or cadence, affects the heart rate (HR) response to three sets of 10 repetitions of resistance exercise at slow (6 seconds/repetition) and fast (2 seconds/repetition) cadences.
The 12 Repetition Maximum (12-RM) load on the angled leg press was determined for 16 moderately trained males (26.8 ± 6.2 yrs, 177.7 ± 6.3 cm, 77.0 ± 10.9 kg). To ensure safe, proper form across all sets, the 12-RM was tested at the slow cadence, and only 10 repetitions/set were performed during trials. Three successive sets of 10 repetitions, with three minutes rest between sets, were completed at each cadence, requiring 60 seconds to complete each slow set, 20 seconds to complete each fast set. Continuous HR was assessed by electrocardiogram from rest throughout exercise, and to recovery. Repeated-Measures (RM) ANOVA was applied, evaluating HR at each cadence for the exercises performed. Bonferroni adjustment resulted in a statistical significance of p < 0.017.
Peak HR (slow) was 112.8 ± 12.2 (set 1), 115.6 ± 13.9 (set 2) and 119.1 ± 17.1 (set 3) bpm. Peak HR (fast) was 118.0 ± 10.5 (set 1), 116.0 ± 10.1 (set 2) and 116.8 ± 10.2 (set 3) bpm. Significant change occurred for the increase in peak HR at the slow cadence only, with the fast cadence showing no increase, as both conditions demonstrate different response patterns.
When three sets of 10 repetitions are performed on the angled leg press at a slow cadence, a significant increase in peak HR occurs for the sets, while the fast cadence does not demonstrate an increase in peak HR values. The is presumed in part due to influences of the pressor response, and the longer work duration for the slow cadence of 60 seconds required per set of 10 repetitions, as compared with the shorter work duration of 20 seconds for 10 repetitions per set at the fast cadence.
Acute variability of the peak HR response to resistance exercise is possible through program modification. For a traditional resistance exercise arrangement such as three sets of 10 repetitions, it is possible to limit elevations in peak HR across sets by using short duration sets with fast repetitions, which may benefit populations for whom cardiovascular workload may be of concern.