Post-exercise heart rate recovery kinetics in female university players and non-players in Bangladesh

Abstract

Background and Study Aim. Heart rate recovery (HRR) following exercise is a practical, noninvasive indicator of cardiovascular and cardiac autonomic function. Regular sports participation is associated with adaptations in resting cardiovascular function and recovery responses. Post-exercise HRR among young women in South Asian university settings is relevant to the assessment of cardiovascular recovery in this population. In particular, differences between trained and untrained women may vary according to whether recovery is assessed using absolute heart rate or expressed relative to individual heart-rate reserve. The present study therefore aimed to compare resting heart rate, absolute post-exercise heart rate recovery, and heart-rate-reserve-relative recovery between trained and untrained female university students in Bangladesh. Materials and Methods. A cross-sectional comparative study was conducted among 40 female undergraduate students at Jashore University of Science and Technology (JUST), Bangladesh. Participants comprised university players (n = 20) and non-players (n = 20), aged 18–25 years. Body mass index (BMI), resting heart rate, and peak heart rate were assessed. Following a standardized warm-up, participants completed a progressive treadmill exercise bout to volitional exhaustion. Heart rate was continuously monitored using a Polar H10 chest strap, and recovery heart rate was recorded at 30-s intervals for 300 s following exercise. Recovery heart rate was analyzed as the observed heart rate at each recovery time point, while percentage heart-rate recovery (%HRR) was calculated relative to individual heart-rate reserve. Independent-samples t-tests were used for group comparisons at individual recovery time points, with Holm adjustment applied across the ten comparisons within each recovery outcome. A two-way repeated-measures analysis of variance was used for recovery heart rate across time, with statistical significance set at p < .05. Results. BMI did not differ statistically between players and non-players (21.42 ± 2.90 vs. 21.64 ± 3.44 kg/m²; p = .828), and peak heart rate also did not differ statistically (192.05 ± 7.39 vs. 191.75 ± 4.33 beats·min⁻¹; p = .876). Resting heart rate was lower in players than non-players (62.80 ± 6.92 vs. 74.20 ± 3.11 beats·min⁻¹; p < .001; d = −2.13). Recovery heart rate was lower in players at 60, 90, 120, and 300 s in the nominal analyses; however, none of the ten time-point comparisons remained statistically significant after Holm adjustment (adjusted p ≥ .070). The repeated-measures analysis showed a significant main effect of time (Wilks' Λ = .006, F[9,30] = 584.66, p < .001) and a significant between-subjects group effect (F[1,38] = 4.59, p = .039), but no time × group interaction (Wilks' Λ = .706, F[9,30] = 1.39, p = .237). For %HRR, none of the ten time-point comparisons was statistically significant after Holm adjustment (adjusted p ≥ .460). Conclusions. Female university players at JUST demonstrated a substantially lower resting heart rate than non-players. Recovery heart rate was lower in players at several individual time points in nominal testing, but these time-point differences were not statistically significant after Holm adjustment. The repeated-measures analysis indicated a significant overall group effect in recovery heart rate but no evidence that the shape of the recovery trajectory differed between groups. For %HRR, no time-point comparison remained statistically significant after multiplicity adjustment. These findings support a difference in resting heart rate and in the overall level of observed recovery heart rate, while providing limited evidence for a distinct reserve-relative recovery trajectory between the two groups.