This study examined the effect of exercise mode on geometrical, and time and frequency domain measures of heart rate variability (HRV) during steady-state, moderate intensity exercise of the same HR. Seventeen healthy, active male participants volunteered for this study and completed a treadmill VO2max determination. One week later, cardiorespiratory, perceptual and HRV measures were recorded during seated rest (15 min) and consecutive bouts (15 min) of steady-state exercise at 50 and 65% of maximal HR. Exercise was performed using either upper body (arm ergometer), lower body (cycle) or whole body (treadmill) modes. Separated by 1 week and in a random order, participants undertook the same procedures with the remaining exercise modes. Cardiorespiratory, perceptual and HRV responses were determined during rest and steady-state exercise and analysed by two-way (mode vs. stage) repeated measures ANOVA and post hoc pairwise comparisons. Apart from a reduced respiratory rate during lower body exercise, whole and lower body exercise resulted in similar cardiorespiratory, perceptual and HRV responses. Compared to whole or lower body exercise, upper body exercise resulted in significantly (P < 0.05) greater measures of HRV particularly those within the very low (0-0.04 Hz) and low (0.04-0.15 Hz) frequency bands, greater rating of perceived exertion and less oxygen consumption. Upper body, moderate intensity exercise resulted in greater HRV compared to whole or lower body exercise with further studies necessary to elucidate the mechanisms and clinical implications for this greater HRV.

A unique combination of primarily attacking performance indicators provided the greatest explanation of match outcome and ladder position in the NRL. These results could be used by NRL coaches and analysts as a basis for the development of practice conditions and game strategies that may increase their teams' likelihood of success. Beyond rugby league, this study presents analytical techniques that could be applied to other sports when examining the relationships between performance indicators and match derivatives.

The initial bout appeared to provide protection against a number of muscle damage indicators suggesting a greater need for recovery following the initial session of typical lower body resistance exercises in resistance-untrained men although sub-maximal running should be avoided following the first two sessions.

The reduction of core body temperature (T C ) is vitally important in the treatment of hyperthermia; however, little is known regarding the impact of cooling treatments on the autonomic control of heart rate (HR). The aim of the present study was to examine the influence of three field-based hyperthermia treatments on the neural control of HR via heart rate variability (HRV).

The aim of this study was to examine the influence of weekly training including a competitive game on heart rate (HR) variability (HRV). Youth players (n=9, age 17-20 years) were monitored during daily supine rest (10 min) and standing (8 min), 5 times over 8 days. Heart rate recordings were analysed for time domain, frequency (e. g. low frequency [LF], high frequency [HF]) domain and non-linear measures of HRV and compared using ANOVA or Friedman's tests. Relationships between HRV and training workloads were examined via Spearman rank rho (ρ) correlation coefficients. Prior to a game, mean HR was significantly increased and remained elevated until 2 days post-game while parasympathetic modulations (HF) were significantly reduced (p<0.05). The supine to standing change in HRV was significantly reduced for up to 4 days post-game (LF/HF ratio, - 1.0±2.9 vs. - 3.0±1.9, p<0.05). These results confirm that prior to a game, players exhibited reduced parasympathetic and/or predominant sympathetic modulation with the game significantly reducing autonomic responses to standing for up to the following 4 days. Identification of day to day fluctuations in HRV may provide a helpful tool for monitoring player workload to maximise training and game performance.