James Mathew Green

Overall and differentiated ratings of perceived exertion at the respiratory compensation threshold: effects of gender and mode

Research on gender differences in ratings of perceived exertion (RPE) has been equivocal with few studies comparing exercise modes and differentiated RPE. The current study examined gender differences in overall and differentiated RPE at the respiratory compensation threshold (RCT) during cycling and treadmill exercise. Each minute during a maximal treadmill and maximal cycling test, men (n=18) and women (n=16) estimated RPE corresponding to overall (RPE-O), legs (RPE-L), and breathing/chest (RPE-C) exertion. A 2 (gender) × 2 (mode) × 3 (RPE-O, RPE-L, RPE-C) repeated measures MANOVA revealed no significant mode × gender or RPE × gender interactions. The exercise mode × RPE interaction approached significance (P=0.055) when cycling [mean (SD) 14.8 (2.9)] and treadmill exercise [12.8 (2.9)] were compared. No main effects for gender [men: 13.7 (2.6), women: 13.4 (2.6)] were detected. Main effects for mode showed RPE to be significantly greater during cycling [14.4 (2.8)] versus treadmill exercise [12.7 (2.9)]. Main effects for differentiated RPE showed RPE-L [13.8 (2.6)] to be significantly greater than RPE-O [13.5 (2.6)] and RPE-C [13.3 (2.6)]. Results suggest that overall and differentiated RPE at the RCT are not significantly different between genders during cycling or treadmill exercise. While RPE-L was statistically greater than RPE-O and RPE-C, the magnitude of the differences makes this result of little practical significance. The marginal interaction suggests greater RPE-L values might be expected at the RCT during cycling versus treadmill exercise. However, results suggest that minimal RPE differences exist between men and women during cycling and treadmill exercise.

Effects of saddle height on economy and anaerobic power in well-trained cyclists.

Peveler, WW and Green, JM. Effects of saddle height on economy and anaerobic power in well-trained cyclists. J Strength Cond Res 25(3): 629-633, 2011-In cycling, saddle height adjustment is critical for optimal performance and injury prevention. A 25-35° knee angle is recommended for injury prevention, whereas 109% of inseam, measured from floor to ischium, is recommended for optimal performance. Previous research has demonstrated that these 2 methods produce significantly different saddle heights and may influence cycling performance. This study compared performance between these 2 methods for determining saddle height. Subjects consisted of 11 well-trained (&OV0312;o2max = 61.55 ± 4.72 ml·kg−1·min−1) male cyclists. Subjects completed a total of 8 performance trials consisting of a graded maximal protocol, three 15-minute economy trials, and 4 anaerobic power trials. Dependent measures for economy (&OV0312;o2, heart rate, and rating of perceived exertion) and anaerobic power (peak power and mean power) were compared using repeated measures analysis of variance (α = 0.05). &OV0312;o2 was significantly lower (reflecting greater economy) at a 25° knee angle (44.77 ± 6.40 ml·kg−1·min−1) in comparison to a 35° knee angle (45.22 ± 6.79 ml·kg−1·min−1) and 109% of inseam (45.98 ± 5.33 ml·kg−1·min−1). Peak power at a 25° knee angle (1,041.55 ± 168.72 W) was significantly higher in relation to 109% of inseam (1,002.05 ± 147.65 W). Mean power at a 25° knee angle (672.37 ± 90.21 W) was significantly higher in relation to a 35° knee angle (654.71 ± 80.67 W). Mean power was significantly higher at 109% of inseam (662.86 ± 79.72 W) in relation to a 35° knee angle (654.71 ± 80.67 W). Use of 109% of inseam fell outside the recommended 25-35° range 73% of the time. Use of 25° knee angle appears to provide optimal performance while keeping knee angle within the recommended range for injury prevention.

Effects of standing vs. seated posture on repeated Wingate performance.

Standing during cycling may increase overall muscular activity. However, effects of standing vs. seated posture on performance measures during repeated bouts have not been extensively explored. The purpose of this study was to examine the effects of standing vs. seated posture on repeated Wingate performance. Healthy volunteers (n = 35) performed 3 consecutive Wingate anaerobic power tests (W1, W2, W3) in a standing (STA) as well as seated (SIT) posture. Within-group comparisons were made for peak power, mean power, minimum power, and fatigue index. Results were considered significant at p <= 0.05. No significant differences were found for peak power in W1, W2, orW3. No significant difference was found for mean power in W1 or W2, but significant differences were found for mean power in W3 (STA: 451.5 +- 105.3, SIT: 425.7 +- 110.0); minimum power in W1 (STA: 433.6 +- 100.8, SIT: 381.5 +- 96.9), W2 (STA: 348.1 +- 112.9, SIT: 308.0 +- 95.8), W3 (STA: 292.0 +- 103.6, SIT: 265.3 +- 90.8); and fatigue index: W1 (STA: 51.3 +- 10.7, SIT: 56.9 +- 9.3), W2 (STA: 56.5 +- 12.6, SIT: 61.8 +- 12.2), W3 (STA: 59.4 +- 13.1, SIT: 63.6 +- 12.4). Results suggest that a standing posture enhances performance during repeated Wingate cycling. The enhancement is most likely due to an attenuated loss in power, which in turn improves fatigue index.

Heart rate and ratings of perceived exertion during treadmill and elliptical exercise training.

Elliptical exercise has recently increased in popularity. However, little is known regarding heart rate and perceptual responses during this exercise mode even though such information is important with respect to prescribing and regulating exercise intensity. In the current study, heart rate and perceived exertion were compared between treadmill and elliptical exercise. During treadmill exercise (TMEST) participants estimated RPE-Overall as well as RPE-Legs and RPE-Chest. Two elliptical sessions followed: (1) RPE estimation during elliptical exercise (ELEST): HR (b/min.) from TMEST was achieved during elliptical exercise, with participants estimating RPE-Overall, RPE-Legs, and RPE-Chest. (2) RPE production during elliptical exercise (ELPROD): RPE-Overall from TMEST was produced during elliptical exercise. There were no significant differences between modes for RPE-Overall (TMEST: 11.2 ± 2.2 vs ELEST: 11.9 ± 3.2) or RPE-Chest (TMEST: 11.0 ± 2.4 vs ELEST: 11.7 ± 3.2). Mean RPE-Legs was significantly different (TMEST: 11.2 ± 2.4 vs ELEST: 12.5 ± 3.1). Heart rate was not significantly different between TMEST (163 ± 16.6) and ELPROD (159 ± 20.0). Analysis indicated elliptical exercise is perceived as more intense with respect to leg (RPE-Legs) exertion. Further, RPE-Overall appears effective for regulating heart rate during elliptical exercise.

Session ratings of perceived exertion responses during resistance training bouts equated for total work but differing in work rate.

Abstract Kraft, JA, Green, JM, and Thompson, KR. Session ratings of perceived exertion responses during resistance training bouts equated for total work but differing in work rate. J Strength Cond Res 28(2): 540–545, 2014—Session ratings of perceived exertion (SRPE) during resistance training may be influenced by specific exercise parameters. The purpose of this study was to examine the influence of work rate (total work per unit time) and recording time on SRPE. Participants performed 3 exercise bouts of bench press, lat pull-down, overhead press, upright row, triceps extension, and biceps curl at 60% of predetermined 1 repetition maximum according to these protocols: (a) 3 sets × 8 repetitions (reps) × 1.5 minutes of recovery, (b) 3 sets × 8 reps × 3 minutes of recovery, and (c) 2 sets × 12 reps × 3 minutes of recovery. Session ratings of perceived exertion for the 3 × 8 × 1.5-minute recovery (5.3 ± 1.8) and 2 × 12 × 3-minute recovery trials (6.2 ± 1.7) were significantly greater vs. 3 × 8 × 3-minute recovery trial (4.2 ± 1.8). The difference approached significance between work rate–matched protocols (p = 0.08). No difference was observed between SRPE at 15 minutes (5.1 ± 1.8) vs. 30 minutes (5.2 ± 1.9) post exercise. Post-set in-task ratings of perceived exertion were higher for the 2 × 12 × 3-minute recovery trial (5.9 ± 1.4) vs. 3 × 8 × 1.5-minute recovery trial (4.8 ± 1.2) and 3 × 8 × 3-minute recovery trial (4.0 ± 1.6). The difference approached significance (p = 0.07) for the 3 × 8 × 3-minute recovery trial vs. 3 × 8 × 1.5-minute recovery trial. Session ratings of perceived exertion responded to changes in work rate with no significant difference at matched work rates, indicating that SRPE is responsive to training load. Results indicated that more proximal monitoring (15 minutes post exercise) yielded reliable estimates of SRPE increasing the practical utility of the measure.

Effects of Heat Exposure and 3% Dehydration Achieved Via Hot Water Immersion on Repeated Cycle Sprint Performance

Kraft, JA, Green, JM, Bishop, PA, Richardson, MT, Neggers, YH, and Leeper, JD. Effects of heat exposure and 3% dehydration achieved via hot water immersion on repeated cycle sprint performance. J Strength Cond Res 25(3): 778-786, 2011-This study examined effects of heat exposure with and without dehydration on repeated anaerobic cycling. Males (n = 10) completed 3 trials: control (CT), water-bath heat exposure (∼39°C) to 3% dehydration (with fluid replacement) (HE), and similar heat exposure to 3% dehydration (DEHY). Hematocrit increased significantly from pre to postheat immersion in both HE and DEHY. Participants performed 6 × 15s cycle sprints (30s active recovery). Mean Power (MP) was significantly lower vs. CT (596 ± 66 W) for DEHY (569 ± 72 W), and the difference approached significance for HE (582 ± 76 W, p = 0.07). Peak Power (PP) was significantly lower vs. CT (900 ± 117 W) for HE (870 ± 128 W) and approached significance for DEHY (857 ± 145 W, p = 0.07). Postsprint ratings of perceived exertion was higher during DEHY (6.4 ± 2.0) and HE (6.3 ± 1.6) than CT (5.7 ± 2.1). Combined heat and dehydration impaired MP and PP (decrements greatest in later bouts) with HE performance intermediate to CT and DEHY.

Work distribution influences session ratings of perceived exertion response during resistance exercise matched for total volume.

Abstract Kraft, JA, Green, JM, and Gast, TM. Work distribution influences session ratings of perceived exertion response during resistance exercise matched for total volume. J Strength Cond Res 28(7): 2042–2046, 2014—Session ratings of perceived exertion (SRPE) are sensitive to changes in total work volume and work rate during resistance training. This study examined the influence of work distribution (varied load, set, and repetitions [reps]) on SRPE in 2 resistance exercise trials matched for total work volume (sets × reps × percentage of 1 repetition maximum [% 1RM]) and work rate (total work volume/time). Participants completed a low load/high rep (LLHR) trial (2 sets × 12 reps × 3-minute recovery at ∼60% 1RM) and a high load/low rep (HLLR) trial (3 sets × 6 reps × 1.5-minute recovery at ∼80% 1RM) of the bench press, lat pull-down, overhead press, upright row, triceps extension, and biceps curl. A 2-minute recovery separated each exercise in both trials. Session ratings of perceived exertion and recovery heart rate (HR) were recorded 20 minutes after exercise. Preset and postset RPE and HR were higher for HLLR vs. LLHR (3.1 ± 1.6; 104 ± 15 b·min−1 vs. 2.1 ± 1.3; 98 ± 10 b·min−1) and (5.5 ± 0.9; 139 ± 14 b·min−1 vs. 4.4 ± 0.9; 131 ± 12 b·min−1), respectively. Session RPE was higher for HLLR (5.7 ± 1.4) vs. LLHR (4.3 ± 1.4) with no difference in recovery HR. Session ratings of perceived exertion was greater with higher load despite matched total volumes and work rates. Higher preset acute RPE and HR in HLLR may indicate differences in recovery between sets. Higher postset acute RPE and HR in HLLR indicated increased difficulty of individual sets in HLLR, which likely contributed to SRPE differences. Practitioners can be confident that SRPE accurately reflects changes in training load when the number of sets, reps, and loads are altered within routine training.

Crossmodal Session Rating of Perceived Exertion Response at Low and Moderate Intensities

Green, JM, Laurent, CM, Bacon, NT, ONeal, EK, Davis, JK, and Bishop, PA. Cross-modal session rating of perceived exertion response at low and moderate intensities. J Strength Cond Res 25(6): 1598-1604, 2011—Session rating of perceived exertion (SRPE) permits global effort estimations after an exercise bout and has shown promise for evaluating training load. However, factors mediating SRPE are not well understood. The purpose of this study was to compare SRPE between cycling and treadmill exercise at low and moderate intensities. In a counterbalanced order, male subjects (n = 7) completed a o2max trial on a cycle ergometer and a motor-driven treadmill. Then, participants completed trials at 50 and 75% mode-specific o2max on a cycle ergometer (BK75, BK50) and a treadmill (TM75, TM50) to achieve ∼400-kcal energy expenditure per trial. Acute RPE (i.e., during exercise) at 5 minutes, midway, and test termination were recorded with SRPE (20-minutes postexercise) expressed as overall (SRPEO), legs (SRPEL), and breathing also recorded were heart rate (HR) and change in rectal temperature (ΔTrec). Significance was accepted at p ≤ 0.05. Repeated-measures analysis of variance revealed significantly greater SRPE for higher intensities within each mode. Crossmodal comparisons also show a higher SRPE at moderate (75% o2max) intensities [SRPEO] = BK75: 7.6 ± 1.0, TM75: 6.9 ± 1.3) vs. lower (50% o2max) intensities (BK50: 4.6 ± 1.4, TM50: 4.6 ± 1.1). Within modes, SRPE corresponded well with ΔTrec and HR. Acute RPE was linked with intensity and drifted upward across time. Results indicated that overall and differentiated SRPEs are magnified with exercise intensity with the corresponding disruption in internal environment potentially mediating subjective responses. From a practical application standpoint, SRPE provides a subjective assessment for immediate evaluation of daily training. Results indicate that, when using SRPE to monitor training, consideration should be given to responses across differing exercise modes.

EFFECTS OF STANDING VERSUS SEATED POSTURE ON REPEATED WINGATE PERFORMANCE

Standing during cycling may increase overall muscular activity. However, effects of standing vs. seated posture on performance measures during repeated bouts have not been extensively explored. The purpose of this study was to examine the effects of standing vs. seated posture on repeated Wingate performance. Healthy volunteers (n = 35) performed 3 consecutive Wingate anaerobic power tests (W1, W2, W3) in a standing (STA) as well as seated (SIT) posture. Within-group comparisons were made for peak power, mean power, minimum power, and fatigue index. Results were considered significant at p ≤ 0.05. No significant differences were found for peak power in W1, W2, or W3. No significant difference was found for mean power in W1 or W2, but significant differences were found for mean power in W3 (STA: 451.5 ± 105.3, SIT: 425.7 ± 110.0); minimum power in W1 (STA: 433.6 ± 100.8, SIT: 381.5 ± 96.9), W2 (STA: 348.1 ± 112.9, SIT: 308.0 ± 95.8), W3 (STA: 292.0 ± 103.6, SIT: 265.3 ± 90.8); and fatigue index: W1 (STA: 51.3 ± 10.7, SIT: 56.9 ± 9.3), W2 (STA: 56.5 ± 12.6, SIT: 61.8 ± 12.2), W3 (STA: 59.4 ± 13.1, SIT: 63.6 ± 12.4). Results suggest that a standing posture enhances performance during repeated Wingate cycling. The enhancement is most likely due to an attenuated loss in power, which in turn improves fatigue index.