Heart Rate Variability Threshold Evaluation During Arm and Leg Cycling

Background: The Heart Rate Variability Threshold (HRVT) is a point of deflection in heart rate variability assessed during incremental exercise to exhaustion. This threshold is thought to represent a shift in the autonomic balance. Purpose: The purpose of this study was to evaluate (HRVT) during arm (AC) and leg cycling (LC). Methods: There were twenty-three participants (age: 23.3±4.7 years; height: 168.6±7.5 cm; weight 66.8±8.9 kg). Participants completed two graded exercise tests, one for AC and one for LC on different days. They wore a heart rate monitor which recorded R-R intervals. The test performed was a graded exercise test to exhaustion (GXT) using a ramp protocol. The root mean square of successive differences between normal heartbeats (RMSSD) of the R-R intervals during the GXT was calculated using specialized software. A time-varying moving average (64 second window and 3 second shift) was used. A piecewise fitting function consisting of two linear functions was used to detect time and RMSSD at HRVT. The time (as percentage of the total time to exhaustion) at which HRVT occurred was also calculated. Log transformation was performed in case the normality assumption was violated. A paired t-test was run for the outcomes of interest. Mean and standard deviations were reported and an alpha value of p Results: Log transformation was performed on the RMSSD and percentage at HRVT. There was no significant difference in time at HRVT (p=0.36) between AC (4.2 ± .1.0 minutes) and LC (3.9 ± 1.6 minutes) or percentage at threshold (p=0.85) between AC (49.3 ± 11.9%) and LC (50.4 ± 20.1%). There was also no significant difference in RMSSD at HRVT (p=0.93) between arm (1.3 ± 0.36 ms) and leg cycling (1.3 ± 0.54 ms). Conclusion: Time, RMSSD, and percentage at HRVT were not different between exercise modes. Autonomic balance, as measured by heart rate variability threshold, does not seem to be influenced by exercise modality

Spatial Awareness is Related to Moderate Intensity Running during a Collegiate Rugby Match

International Journal of Exercise Science 9(5): 599-606, 2016. The purpose of the present study was to evaluate the relationship between spatial awareness, agility, and distance covered in global positioning system (GPS) derived velocity zone classifications during a collegiate rugby match. Twelve American collegiate rugby union players (mean±SD; age: 21.2±1.4 y; weight: 85.0±16.0 kg; 7 forwards & 5 backs) on a single team volunteered to participate in this investigation. The distances travelled at low (walking/jogging; \u3c2.7m/s), moderate (cruising/striding; 2.7-5.0 m/s), and high intensities (running/sprinting; \u3e5.0 m/s) were measured for each player using GPS sensors and normalized according to playing time during an official USA Rugby match. Spatial awareness was measured as visual tracking speed from one core session of a 3-dimensional multiple-object-tracking speed (3DMOTS) test (1.35±0.59 cm·sec-1). Agility was assessed utilizing the pro agility (5.05±0.28 sec) and t drill (10.62±0.39 sec). Analysis of variance revealed that athletes travelled the greatest distance during walking/jogging (39.5±4.5 m·min-1) and least distance during running/sprinting (4.9±3.5 m·min-1). Pearson product moment correlations revealed that only distance covered while cruising/striding (20.9±6.5 m·min-1) was correlated to spatial awareness (r=0.798, p=0.002). Agility did not correlate to distance covered at any velocity zone or spatial awareness. Spatial awareness, as determined by 3DMOTS, appears to be related to the moderate intensity movement patterns of rugby union athletes

Analysis of Comparative Enjoyment Following High to Moderate Intensity Upper Body Cycling and Lower Body Cycling in Lean and Obese

The combination of utilizing differing aerobic exercise prescriptions such as arm cycling and traditional leg cycling at varying exercise intensities may affect an individual’s enjoyment of exercise. PURPOSE: This study compared levels of perceived enjoyment obtained following isocaloric arm and leg cycling trials performed at heavy and moderate intensities among lean and average (LA) and overfat and obese individuals (OFO). METHODS: Participants included 36 young adults divided into two groups based on their Fat Mass Index (FMI) (LA=4.6±1.7 FM kg/m2, OFO=9.9±3.5 FM kg/m2). They completed a combination of four arm and leg cycling isocaloric trials at moderate and heavy intensities based on their mode-specific ventilatory threshold and maximal power output attained during maximal ramp tests. Participants remained seated for 10 minutes following each 100 kcal isocaloric trial before completing the Physical Activity Enjoyment Scale questionnaire (PACES). A higher PACES score indicates greater enjoyment (range=18–126). To determine the effect of mode (arm x leg cycling), intensity (heavy x moderate), and FMI (LA x OFO) on PACES score, likelihood linear mixed-effects models were fitted. Assumptions of residual normality and homoscedasticity were visually verified using q-q plots and model predicted scores vs. residuals plots, respectively. PACES score was modeled using participant as a random effect, and mode, intensity, and FMI as fixed effects. Fixed effects were analyzed for significant main effects and interactions via F tests. Alpha was set at 0.05. RESULTS: No significant interactions were found between mode, intensity, and FMI (p\u3e0.05). PACES scores following arm cycling at heavy intensity (104±16), arm cycling at moderate intensity (100±18), leg cycling at heavy intensity (102±13), and leg cycling at moderate intensity (103±20) had no significant interaction. No main effects were found between LA (103±17) and OFO (102±17) groups. CONCLUSION: In conclusion, neither mode nor intensity or FMI affected PACES scores for LA or OFO groups. Therefore, individuals should explore a variety of aerobic exercise options to identify individual preferences. Future research should investigate the chronic effects of body composition on exercise mode and intensity on enjoyment levels

Moderate Intensity Arm Cycling as a Viable Exercise Alternative for Overfat and Obese Individuals with Poor Cardiorespiratory Fitness

The prescription of aerobic exercise engaging the arms may extend the reach of physical activity and improve cardiorespiratory fitness in individuals with obesity. PURPOSE: This study compared the acute cardiopulmonary responses obtained during isocaloric arm and leg cycling trials performed at different intensities among individual’s with and without excess body fat. METHODS: Participants were 37 young adults divided into two groups based on their fat mass index, lean and average (LA) and overfat and obese (OFO). They were tested for mode-specific work rate at the ventilatory threshold (VT) and volitional fatigue (VF) during two randomized ramp tests. The main experiments consisted of four randomized constant work rate isocaloric trials for arm and leg cycling performed at moderate (i.e., work rate equivalent to 80% of VT obtained during the ramp tests) and heavy (i.e., work rate equivalent to 30% of the difference between VT and VF obtained during the ramp tests). The time to expend 100 kcal (Tkcal100) was recorded, and oxygen uptake (V̇O2) was averaged for the duration of the tests. A two-way mixed factorial ANCOVA with physical activity level as a covariate determined work rate at VT, and V̇O2 peak responses to the ramp tests. A three-way mixed factorial ANCOVA with the mode-specific fitness difference and physical activity level as covariates were run for Tkcal100 and V̇O2 obtained during isocaloric trials. Effect sizes (Cohen’s d) were calculated and interpreted with magnitude thresholds and significance level was set at p≤0.05. RESULTS: Significantly lower work rates at VT and V̇O2 peak were shown for the OFO during ramp tests. Tkcal100 was significantly longer for OFO in comparison to LA during isocaloric trials (d=0.36). The V̇O2 responses relative to body mass were significantly greater in leg cycling than arm cycling, while effect sizes were larger during heavy exercise (d=1.45) compared to moderate (d=1.13). CONCLUSION: Arm cycling performed at moderate intensity could be an alternative for young adults with excess body fat and poor cardiorespiratory fitness since this exercise modality elicited a sufficient metabolic response above three metabolic equivalents, which is within the moderate intensity domain suggested by current guidelines

Mathematical Modeling and Expression of Heart Rate Deflection Point Using Heart Rate and Oxygen Consumption

International Journal of Exercise Science 10(4): 592-603, 2017. Heart rate deflection point (HRDP) can be determined through different mathematical-modeling procedures, such as bi-segmental linear regression (2SEG) or maximal distance model (Dmax). The purpose was to compare heart rate (HR) and oxygen consumption (VO2) at HRDP when using 2SEG and Dmax, and to examine their relationships with respiratory compensation point (RCP) and running performance. Nineteen participants completed a graded exercise test (GXT), to determine HRDP and RCP, and a 5km treadmill time trial (5Ktime). No differences were found in HR or VO2 when comparing HRDP2SEG, HRDPDmax, and RCP. Strong correlations were found between HRDP2SEG, HRDPDmax, and RCP when using HR and VO2. No relationships were found between 5Ktime and HR at HRDP or RCP; however, strong relationships were found with VO2. While 2SEG and Dmax may be interchangeable in determining HRDP, VO2 at HRDP and RCP yielded stronger relationships to 5Ktime than HR. Therefore, VO2 at HRDP may be a better predictor of running performance than HR