Your article is protected by copyright and all rights are held exclusively by Springer-Verlag. Th... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your work, please use the accepted author's version for posting to your own website or your institution's repository. You may further deposit the accepted author's version on a funder's repository at a funder's request, provided it is not made publicly available until 12 months after publication.
It has been suggested that the time spent at a high stroke volume (SV) is important for improving... more It has been suggested that the time spent at a high stroke volume (SV) is important for improving maximal cardiac function. The aim of this study was to examine the effect of recovery intensity on cardiovascular parameters during a typical high-intensity interval training (HIIT) session in fourteen well-trained cyclists. Oxygen consumption (VO 2 ), heart rate (HR), SV, cardiac output (Qc), and oxygenation of vastus lateralis (TSI) were measured during a HIIT (3×3-min work period, 2 min of recovery) session on two occasions. VO 2 , HR and Qc were largely higher during moderate-intensity (60%) compared with low-intensity (30%) (VO 2 , effect size; ES = +2.6; HR, ES = +2.8; Qc, ES = +2.2) and passive (HR, ES = +2.2; Qc, ES = +1.7) recovery. By contrast, there was no clear difference in SV between the three recovery conditions, with the SV during the two active recovery periods not being substantially different than during exercise (60%, ES = −0.1; 30%, ES = −0.2). To conclude, moderateintensity recovery may not be required to maintain a high SV during HIIT.
European journal of applied physiology, Jan 29, 2014
We investigated the effect of post-exercise sauna bathing on plasma volume (PV) expansion and whe... more We investigated the effect of post-exercise sauna bathing on plasma volume (PV) expansion and whether such responses can be tracked by changes in heart rate (HR)-based measures. Seven, well-trained male cyclists were monitored for 35 consecutive days (17 days baseline training, 10 days training plus sauna, 8 days training). Sauna exposure consisted of 30 min (87 °C, 11 % relative humidity) immediately following normal training. Capillary blood samples were collected while resting seated to assess PV changes. HR (HRwake) and vagal-related HR variability (natural logarithm of square root mean squared differences of successive R-R intervals, ln rMSSDwake) were assessed daily upon waking. A sub-maximal cycle test (5 min at 125 W) was performed on days 1, 8, 15, 22, 25, 29, and 35 and HR recovery (HRR60s) and ln rMSSDpostex were assessed post-exercise. Effects were examined using magnitude-based inferences. Compared with baseline, sauna resulted in: (1) peak PV expansion after four expos...
The measurement of heart rate variability (HRV) is often considered a convenient non-invasive ass... more The measurement of heart rate variability (HRV) is often considered a convenient non-invasive assessment tool for monitoring individual adaptation to training. Decreases and increases in vagal-derived indices of HRV have been suggested to indicate negative and positive adaptations, respectively, to endurance training regimens. However, much of the research in this area has involved recreational and well-trained athletes, with the small number of studies conducted in elite athletes revealing equivocal outcomes. For example, in elite athletes, studies have revealed both increases and decreases in HRV to be associated with negative adaptation. Additionally, signs of positive adaptation, such as increases in cardiorespiratory fitness, have been observed with atypical concomitant decreases in HRV. As such, practical ways by which HRV can be used to monitor training status in elites are yet to be established. This article addresses the current literature that has assessed changes in HRV in response to training loads and the likely positive and negative adaptations shown. We reveal limitations with respect to how the measurement of HRV has been interpreted to assess positive and negative adaptation to endurance training regimens and subsequent physical performance. We offer solutions to some of the methodological issues associated with using HRV as a day-to-day monitoring tool. These include the use of appropriate averaging techniques, and the use of specific HRV indices to overcome the issue of HRV saturation in elite athletes (i.e., reductions in HRV despite decreases in resting heart rate). Finally, we provide examples in Olympic and World Champion athletes showing how these indices can be practically applied to assess training status and readiness to perform in the period leading up to a pinnacle event. The paper reveals how longitudinal HRV monitoring in elites is required to understand their unique individual HRV fingerprint. For the first time, we demonstrate how increases and decreases in HRV relate to changes in fitness and freshness, respectively, in elite athletes.
The objective of exercise training is to initiate desirable physiological adaptations that ultima... more The objective of exercise training is to initiate desirable physiological adaptations that ultimately enhance 33 physical work capacity. Optimal training prescription requires an individualised approach, with an appropriate 34 balance of training stimulus and recovery and optimal periodisation. Recovery from exercise involves integrated 35 physiological responses. The cardiovascular system plays a fundamental role in facilitating many of these 36 responses, including thermoregulation and delivery/removal of nutrients and waste products. As a marker of 37 cardiovascular recovery, cardiac parasympathetic reactivation following a training session is highly 38 individualised. It appears to parallel the acute/intermediate recovery of thermoregulatory and vascular systems, 39 as described by supercompensation theory. The physiological mechanisms underlying cardiac parasympathetic 40 reactivation are not completely understood. However, changes in cardiac autonomic activity may provide a 41 proxy measure of the changes in autonomic input to organs, and (by default) the blood flow requirements to 42 restore homeostasis. Metaboreflex stimulation (e.g., muscle and blood acidosis) is likely a key determinant 43 parasympathetic reactivation in the short term (0−90 min post-exercise), whereas baroreflex stimulation (e.g., 44 exercise-induced changes in plasma volume) probably mediates parasympathetic reactivation in the intermediate 45 term (1−48 h post-exercise). Cardiac parasympathetic reactivation does not appear to coincide with the recovery 46
We investigated performance and heart rate (HR) variability (HRV) over consecutive days of cyclin... more We investigated performance and heart rate (HR) variability (HRV) over consecutive days of cycling with post-14 exercise cold water immersion (CWI) or passive recovery (PAS). In a crossover design, 11 cyclists completed 15 two separate 3-d training blocks (120 min cycling per day, 66 maximal sprints, 9 min time trialling [TT]), 16 followed by 2 d of recovery-based training. The cyclists recovered from each training session by standing in 17 cold water (10°C) or at room temperature (27°C) for 5 min. Mean power for sprints, total TT work and HR were 18 assessed during each session. Resting vagal-HRV (natural logarithm of square-root of mean squared differences 19 of successive R−R intervals; ln rMSSD) was assessed after exercise, after the recovery intervention, during 20 sleep and upon waking. CWI allowed better maintenance of mean sprint power (between-trial difference [90% 21 confidence limits]; +12.4%[5.9;18.9]), cadence (+2.0%[0.6;3.5]), and mean HR during exercise 22 (+1.6%[0.0;3.2]) compared with PAS. ln rMSSD immediately following CWI was higher (+144%[92;211]) 23 compared with PAS. There was no difference between the trials in TT performance (−0.2%[−3.5; 3.0]) or 24 waking ln rMSSD (−1.2%[−5.9;3.4]). CWI helps to maintain sprint performance during consecutive days of 25 training, whereas its effects on vagal-HRV vary over time and depend on prior exercise intensity. 26 27 Keywords 28 Autonomic nervous system; training block; high-intensity cycling; sprints; post-exercise recovery; hydrotherapy 31 Elite athletes often train intensely or compete over consecutive days. Cumulative fatigue over such periods of 32 training or competition can reduce athletic performance (Lane and Wenger 2004; Vaile et al. 2008). Adequate 33 recovery between training sessions and/or competitive events is therefore essential to minimise the risk of 34 fatigue and optimise performance. 35 36 Often the duration between training sessions or competition events does not allow for complete recovery. To 37 maintain performance, athletes commonly adopt strategies such as massage, active recovery, compression 38 garments and hydrotherapy to accelerate their recovery. Post-exercise cold water immersion is a popular form of 39 hydrotherapy and can improve recovery and exercise performance during consecutive days (Lane and Wenger
We investigated the effect of hydrotherapy on time-trial performance and cardiac parasympathetic ... more We investigated the effect of hydrotherapy on time-trial performance and cardiac parasympathetic reactivation 13 during recovery from intense training. On three occasions, 18 well-trained cyclists completed 60 min high-14 intensity cycling, followed 20 min later by one of three 10-min recovery interventions: passive rest (PAS), cold 15 water immersion (CWI), or contrast water immersion (CWT). The cyclists then rested quietly for 160 min with 16 R−R intervals and perceptions of recovery recorded every 30 min. Cardiac parasympathetic activity was 17 evaluated using the natural logarithm of the square-root of mean squared differences of successive R−R 18 intervals (ln rMSSD). Finally, the cyclists completed a work-based cycling time-trial. Effects were examined 19 using magnitude-based inferences. Differences in time-trial performance between the three trials were trivial. 20 Compared with PAS, general fatigue was very likely lower for CWI (difference [90% confidence limits; −12% 21 [−18;−5]) and CWT (−11% [−19;−2]). Leg soreness was almost certainly lower following CWI (−22% 22 [−30;−14]) and CWT (−27% [−37; −15]). The change in mean ln rMSSD following the recovery interventions 23 (ln rMSSD Post-interv ) was almost certainly higher following CWI (16.0% [10.4;23.2]) and very likely higher 24 following CWT (12.5% [5.5;20.0]) compared with PAS, and possibly higher following CWI (3.7% [−0.9;8.4])
Purpose We investigated the acute effects of cold water immersion (CWI) or passive recovery (PAS)... more Purpose We investigated the acute effects of cold water immersion (CWI) or passive recovery (PAS) on physiological responses during high-intensity interval training (HIIT). Methods In a crossover design, 14 cyclists completed 2 HIIT sessions (HIIT1 and HIIT2) separated by 30 min. Between HIIT sessions, they stood in cold water (10°C) up to their umbilicus, or at room temperature (27°C) for 5 min. The natural logarithm of square-root of mean squared differences of successive R-R intervals (ln rMSSD) was assessed pre-and post-HIIT1 and HIIT2. Stroke volume (SV), cardiac output ( _ Q), O 2 uptake ( _ VO 2 ), total muscle hemoglobin (t Hb ) and oxygenation of the vastus lateralis were recorded (using near infrared spectroscopy); heart rate, _ Q, and _ VO 2 on-kinetics (i.e., mean response time, MRT), muscle de-oxygenation rate, and anaerobic contribution to exercise were calculated for HIIT1 and HIIT2. Results ln rMSSD was likely higher [between-trial difference (90 % confidence interval) [?13.2 % (3.3; 24.0)] after CWI compared with PAS. CWI also likely increased SV [?5.9 % (-0.1; 12.1)], possibly increased _ Q [?4.4 % (-1.0; 10.3)], possibly slowed _ Q MRT [?18.3 % (-4.1; 46.0)], very likely slowed _ VO 2 MRT [?16.5 % (5.8; 28.4)], and likely increased the anaerobic contribution to exercise [?9.7 % (-1.7; 22.5)].
We compared the effects of an ice-slush beverage (ISB) and a cool liquid beverage (CLB) on cyclin... more We compared the effects of an ice-slush beverage (ISB) and a cool liquid beverage (CLB) on cycling performance, changes in rectal temperature (T re) and stress responses in hot, humid conditions. Ten trained male cyclists/triathletes completed two exercise trials (75 min cycling at ~60% peak power output + 50 min seated recovery + 75% peak power output × 30 min performance trial) on separate occasions in 34°C, 60% relative humidity. During the recovery phase before the performance trial, the athletes consumed either the ISB (mean ± SD −0.8 ± 0.1°C) or the CLB (18.4 ± 0.5°C). Performance time was not significantly different after consuming the ISB compared with the CLB (29.42 ± 2.07 min for ISB vs. 29.98 ± 3.07 min for CLB, P = 0.263). T re (37.0 ± 0.3°C for ISB vs. 37.4 ± 0.2°C for CLB, P = 0.001) and physiological strain index (0.2 ± 0.6 for ISB vs. 1.1 ± 0.9 for CLB, P = 0.009) were lower at the end of recovery and before the performance trial after ingestion of the ISB compared with the CLB. Mean thermal sensation was lower (P T re compared with CLB. Irrespective of exercise performance outcomes, ingestion of ISB during recovery from exercise in hot humid environments is a practical and effective method for cooling athletes following exercise in hot environments.
Your article is protected by copyright and all rights are held exclusively by Springer-Verlag. Th... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your work, please use the accepted author's version for posting to your own website or your institution's repository. You may further deposit the accepted author's version on a funder's repository at a funder's request, provided it is not made publicly available until 12 months after publication.
It has been suggested that the time spent at a high stroke volume (SV) is important for improving... more It has been suggested that the time spent at a high stroke volume (SV) is important for improving maximal cardiac function. The aim of this study was to examine the effect of recovery intensity on cardiovascular parameters during a typical high-intensity interval training (HIIT) session in fourteen well-trained cyclists. Oxygen consumption (VO 2 ), heart rate (HR), SV, cardiac output (Qc), and oxygenation of vastus lateralis (TSI) were measured during a HIIT (3×3-min work period, 2 min of recovery) session on two occasions. VO 2 , HR and Qc were largely higher during moderate-intensity (60%) compared with low-intensity (30%) (VO 2 , effect size; ES = +2.6; HR, ES = +2.8; Qc, ES = +2.2) and passive (HR, ES = +2.2; Qc, ES = +1.7) recovery. By contrast, there was no clear difference in SV between the three recovery conditions, with the SV during the two active recovery periods not being substantially different than during exercise (60%, ES = −0.1; 30%, ES = −0.2). To conclude, moderateintensity recovery may not be required to maintain a high SV during HIIT.
European journal of applied physiology, Jan 29, 2014
We investigated the effect of post-exercise sauna bathing on plasma volume (PV) expansion and whe... more We investigated the effect of post-exercise sauna bathing on plasma volume (PV) expansion and whether such responses can be tracked by changes in heart rate (HR)-based measures. Seven, well-trained male cyclists were monitored for 35 consecutive days (17 days baseline training, 10 days training plus sauna, 8 days training). Sauna exposure consisted of 30 min (87 °C, 11 % relative humidity) immediately following normal training. Capillary blood samples were collected while resting seated to assess PV changes. HR (HRwake) and vagal-related HR variability (natural logarithm of square root mean squared differences of successive R-R intervals, ln rMSSDwake) were assessed daily upon waking. A sub-maximal cycle test (5 min at 125 W) was performed on days 1, 8, 15, 22, 25, 29, and 35 and HR recovery (HRR60s) and ln rMSSDpostex were assessed post-exercise. Effects were examined using magnitude-based inferences. Compared with baseline, sauna resulted in: (1) peak PV expansion after four expos...
The measurement of heart rate variability (HRV) is often considered a convenient non-invasive ass... more The measurement of heart rate variability (HRV) is often considered a convenient non-invasive assessment tool for monitoring individual adaptation to training. Decreases and increases in vagal-derived indices of HRV have been suggested to indicate negative and positive adaptations, respectively, to endurance training regimens. However, much of the research in this area has involved recreational and well-trained athletes, with the small number of studies conducted in elite athletes revealing equivocal outcomes. For example, in elite athletes, studies have revealed both increases and decreases in HRV to be associated with negative adaptation. Additionally, signs of positive adaptation, such as increases in cardiorespiratory fitness, have been observed with atypical concomitant decreases in HRV. As such, practical ways by which HRV can be used to monitor training status in elites are yet to be established. This article addresses the current literature that has assessed changes in HRV in response to training loads and the likely positive and negative adaptations shown. We reveal limitations with respect to how the measurement of HRV has been interpreted to assess positive and negative adaptation to endurance training regimens and subsequent physical performance. We offer solutions to some of the methodological issues associated with using HRV as a day-to-day monitoring tool. These include the use of appropriate averaging techniques, and the use of specific HRV indices to overcome the issue of HRV saturation in elite athletes (i.e., reductions in HRV despite decreases in resting heart rate). Finally, we provide examples in Olympic and World Champion athletes showing how these indices can be practically applied to assess training status and readiness to perform in the period leading up to a pinnacle event. The paper reveals how longitudinal HRV monitoring in elites is required to understand their unique individual HRV fingerprint. For the first time, we demonstrate how increases and decreases in HRV relate to changes in fitness and freshness, respectively, in elite athletes.
The objective of exercise training is to initiate desirable physiological adaptations that ultima... more The objective of exercise training is to initiate desirable physiological adaptations that ultimately enhance 33 physical work capacity. Optimal training prescription requires an individualised approach, with an appropriate 34 balance of training stimulus and recovery and optimal periodisation. Recovery from exercise involves integrated 35 physiological responses. The cardiovascular system plays a fundamental role in facilitating many of these 36 responses, including thermoregulation and delivery/removal of nutrients and waste products. As a marker of 37 cardiovascular recovery, cardiac parasympathetic reactivation following a training session is highly 38 individualised. It appears to parallel the acute/intermediate recovery of thermoregulatory and vascular systems, 39 as described by supercompensation theory. The physiological mechanisms underlying cardiac parasympathetic 40 reactivation are not completely understood. However, changes in cardiac autonomic activity may provide a 41 proxy measure of the changes in autonomic input to organs, and (by default) the blood flow requirements to 42 restore homeostasis. Metaboreflex stimulation (e.g., muscle and blood acidosis) is likely a key determinant 43 parasympathetic reactivation in the short term (0−90 min post-exercise), whereas baroreflex stimulation (e.g., 44 exercise-induced changes in plasma volume) probably mediates parasympathetic reactivation in the intermediate 45 term (1−48 h post-exercise). Cardiac parasympathetic reactivation does not appear to coincide with the recovery 46
We investigated performance and heart rate (HR) variability (HRV) over consecutive days of cyclin... more We investigated performance and heart rate (HR) variability (HRV) over consecutive days of cycling with post-14 exercise cold water immersion (CWI) or passive recovery (PAS). In a crossover design, 11 cyclists completed 15 two separate 3-d training blocks (120 min cycling per day, 66 maximal sprints, 9 min time trialling [TT]), 16 followed by 2 d of recovery-based training. The cyclists recovered from each training session by standing in 17 cold water (10°C) or at room temperature (27°C) for 5 min. Mean power for sprints, total TT work and HR were 18 assessed during each session. Resting vagal-HRV (natural logarithm of square-root of mean squared differences 19 of successive R−R intervals; ln rMSSD) was assessed after exercise, after the recovery intervention, during 20 sleep and upon waking. CWI allowed better maintenance of mean sprint power (between-trial difference [90% 21 confidence limits]; +12.4%[5.9;18.9]), cadence (+2.0%[0.6;3.5]), and mean HR during exercise 22 (+1.6%[0.0;3.2]) compared with PAS. ln rMSSD immediately following CWI was higher (+144%[92;211]) 23 compared with PAS. There was no difference between the trials in TT performance (−0.2%[−3.5; 3.0]) or 24 waking ln rMSSD (−1.2%[−5.9;3.4]). CWI helps to maintain sprint performance during consecutive days of 25 training, whereas its effects on vagal-HRV vary over time and depend on prior exercise intensity. 26 27 Keywords 28 Autonomic nervous system; training block; high-intensity cycling; sprints; post-exercise recovery; hydrotherapy 31 Elite athletes often train intensely or compete over consecutive days. Cumulative fatigue over such periods of 32 training or competition can reduce athletic performance (Lane and Wenger 2004; Vaile et al. 2008). Adequate 33 recovery between training sessions and/or competitive events is therefore essential to minimise the risk of 34 fatigue and optimise performance. 35 36 Often the duration between training sessions or competition events does not allow for complete recovery. To 37 maintain performance, athletes commonly adopt strategies such as massage, active recovery, compression 38 garments and hydrotherapy to accelerate their recovery. Post-exercise cold water immersion is a popular form of 39 hydrotherapy and can improve recovery and exercise performance during consecutive days (Lane and Wenger
We investigated the effect of hydrotherapy on time-trial performance and cardiac parasympathetic ... more We investigated the effect of hydrotherapy on time-trial performance and cardiac parasympathetic reactivation 13 during recovery from intense training. On three occasions, 18 well-trained cyclists completed 60 min high-14 intensity cycling, followed 20 min later by one of three 10-min recovery interventions: passive rest (PAS), cold 15 water immersion (CWI), or contrast water immersion (CWT). The cyclists then rested quietly for 160 min with 16 R−R intervals and perceptions of recovery recorded every 30 min. Cardiac parasympathetic activity was 17 evaluated using the natural logarithm of the square-root of mean squared differences of successive R−R 18 intervals (ln rMSSD). Finally, the cyclists completed a work-based cycling time-trial. Effects were examined 19 using magnitude-based inferences. Differences in time-trial performance between the three trials were trivial. 20 Compared with PAS, general fatigue was very likely lower for CWI (difference [90% confidence limits; −12% 21 [−18;−5]) and CWT (−11% [−19;−2]). Leg soreness was almost certainly lower following CWI (−22% 22 [−30;−14]) and CWT (−27% [−37; −15]). The change in mean ln rMSSD following the recovery interventions 23 (ln rMSSD Post-interv ) was almost certainly higher following CWI (16.0% [10.4;23.2]) and very likely higher 24 following CWT (12.5% [5.5;20.0]) compared with PAS, and possibly higher following CWI (3.7% [−0.9;8.4])
Purpose We investigated the acute effects of cold water immersion (CWI) or passive recovery (PAS)... more Purpose We investigated the acute effects of cold water immersion (CWI) or passive recovery (PAS) on physiological responses during high-intensity interval training (HIIT). Methods In a crossover design, 14 cyclists completed 2 HIIT sessions (HIIT1 and HIIT2) separated by 30 min. Between HIIT sessions, they stood in cold water (10°C) up to their umbilicus, or at room temperature (27°C) for 5 min. The natural logarithm of square-root of mean squared differences of successive R-R intervals (ln rMSSD) was assessed pre-and post-HIIT1 and HIIT2. Stroke volume (SV), cardiac output ( _ Q), O 2 uptake ( _ VO 2 ), total muscle hemoglobin (t Hb ) and oxygenation of the vastus lateralis were recorded (using near infrared spectroscopy); heart rate, _ Q, and _ VO 2 on-kinetics (i.e., mean response time, MRT), muscle de-oxygenation rate, and anaerobic contribution to exercise were calculated for HIIT1 and HIIT2. Results ln rMSSD was likely higher [between-trial difference (90 % confidence interval) [?13.2 % (3.3; 24.0)] after CWI compared with PAS. CWI also likely increased SV [?5.9 % (-0.1; 12.1)], possibly increased _ Q [?4.4 % (-1.0; 10.3)], possibly slowed _ Q MRT [?18.3 % (-4.1; 46.0)], very likely slowed _ VO 2 MRT [?16.5 % (5.8; 28.4)], and likely increased the anaerobic contribution to exercise [?9.7 % (-1.7; 22.5)].
We compared the effects of an ice-slush beverage (ISB) and a cool liquid beverage (CLB) on cyclin... more We compared the effects of an ice-slush beverage (ISB) and a cool liquid beverage (CLB) on cycling performance, changes in rectal temperature (T re) and stress responses in hot, humid conditions. Ten trained male cyclists/triathletes completed two exercise trials (75 min cycling at ~60% peak power output + 50 min seated recovery + 75% peak power output × 30 min performance trial) on separate occasions in 34°C, 60% relative humidity. During the recovery phase before the performance trial, the athletes consumed either the ISB (mean ± SD −0.8 ± 0.1°C) or the CLB (18.4 ± 0.5°C). Performance time was not significantly different after consuming the ISB compared with the CLB (29.42 ± 2.07 min for ISB vs. 29.98 ± 3.07 min for CLB, P = 0.263). T re (37.0 ± 0.3°C for ISB vs. 37.4 ± 0.2°C for CLB, P = 0.001) and physiological strain index (0.2 ± 0.6 for ISB vs. 1.1 ± 0.9 for CLB, P = 0.009) were lower at the end of recovery and before the performance trial after ingestion of the ISB compared with the CLB. Mean thermal sensation was lower (P T re compared with CLB. Irrespective of exercise performance outcomes, ingestion of ISB during recovery from exercise in hot humid environments is a practical and effective method for cooling athletes following exercise in hot environments.
Uploads
Papers by Jamie Stanley