Heart Rate Variability After Different Orders Of Upper- And Lower-body Resistance Exercise In Men

Acute resistance exercise (RE) has been shown to induce similar impacts on heart rate variability (HRV) between upper- and lower-body RE. However, different orders of combined upper- and lower-body RE on HRV are unknown. PURPOSE: To compare the different orders of upper-and lower-body RE on HRV in young men. METHODS: Thirty-two young men (23 ± 4 years old) completed the study. HRV was expressed as natural logarithm (Ln), and included Root mean square successive difference (LnRMSSD), the proportion of NN50 divided by the total number of NN (R-R) intervals (LnPNN50), total power (LnTP), low frequency power (LnLF), and high frequency power (LnHF), and was assessed at rest, 15-20 (R1), and 25-30 (R2) minutes after either order of upper- and lower-body RE at 75% 1-repetition maximum for 3 sets of 10 repetitions with 1.5- and 2-minute rests between sets and exercises, respectively. The upper- and lower-body RE (UL) condition performed latissimus dorsi pulldown and incline chest press first and then knee extension and knee flexion while the lower- and upper-body RE (LU) condition performed knee extension and knee flexion first and then latissimus dorsi pulldown and incline chest press. A 2-way repeated measure ANOVA was used to determine the effect of different orders across time on HRV. RESULTS: There were no significant 2-way interactions for any variables. There were significant (p < 0.05) main effects of time for heart rate (UL: Rest: 62 ± 6, R1: 89 ± 14, R2: 89 ± 14; LU: Rest: 63 ± 6, R1: 90 ± 13, R2: 89 ± 13), LnRMSSD (UL: Rest: 4.01 ± 0.43 ms, R1: 2.86 ± 1.05 ms, R2: 2.85 ± 1.06 ms; LU: Rest: 4.00 ± 0.54 ms, R1: 2.61 ± 0.78 ms, R2: 2.62 ± 0.79 ms), LnPNN50 (UL: Rest: 3.52 ± 0.69, R1: 0.62 ± 1.74, R2: 0.62 ± 1.74; LU: Rest: 3.71 ± 0.34, R1: 0.57 ± 1.84, R2: 0.60 ± 1.88), LnTP (UL: Rest: 78.5 ± 0.8ms2, R1: 7.1 ± 1.2ms2, R2: 7.1 ± 1.3ms2; LU: Rest: 8.6 ± 0.9ms2, R1: 7.3 ± 1.7ms2, R2: 7.3 ± 1.7ms2), LnLF (UL: Rest: 6.8 ± 1.1ms2, R1: 5.5 ± 1.3ms2, R2: 5.4 ± 1.3ms2; LU: Rest: 6.8 ± 1.2ms2, R1: 5.7 ± 1.8ms2, R2: 5.7 ± 1.8ms2), and LnHF (UL: Rest: 8.0 ± 1.1ms2, R1: 5.1 ± 1.9ms2, R2: 5.0 ± 1.9ms2; LU: Rest: 7.9 ± 1.2ms2, R1: 5.0 ± 2.3ms2, R2: 5.1 ± 2.4ms2) such that they increased at R1 and R2 compared to rest after UL and LU. CONCLUSION: These data suggest that acute combined upper- and lower-body RE significantly increases HRV in young men regardless orders of combined upper- and lower-body RE.