Bouts Of Supramaximal Exercise Research Articles

Determinants of the maximal functional reserve during repeated supramaximal exercise by humans: The roles of Nrf2/Keap1, antioxidant proteins, muscle phenotype and oxygenation

When high-intensity exercise is performed until exhaustion a “functional reserve” (FR) or capacity to produce power at the same level or higher than reached at exhaustion exists at task failure, which could be related to reactive oxygen and nitrogen species (RONS)-sensing and counteracting mechanisms. Nonetheless, the magnitude of this FR remains unknown. Repeated bouts of supramaximal exercise at 120% of VO2max interspaced with 20s recovery periods with full ischaemia were used to determine the maximal FR. Then, we determined which muscle phenotypic features could account for the variability in functional reserve in humans. Exercise performance, cardiorespiratory variables, oxygen deficit, and brain and muscle oxygenation (near-infrared spectroscopy) were measured, and resting muscle biopsies were obtained from 43 young healthy adults (30 males). Males and females had similar aerobic (VO2max per kg of lower extremities lean mass (LLM): 166.7 ± 17.1 and 166.1 ± 15.6 ml kg LLM−1.min−1, P = 0.84) and anaerobic fitness (similar performance in the Wingate test and maximal accumulated oxygen deficit when normalized to LLM). The maximal FR was similar in males and females when normalized to LLM (1.84 ± 0.50 and 2.05 ± 0.59 kJ kg LLM−1, in males and females, respectively, P = 0.218). This FR depends on an obligatory component relying on a reserve in glycolytic capacity and a putative component generated by oxidative phosphorylation. The aerobic component depends on brain oxygenation and phenotypic features of the skeletal muscles implicated in calcium handling (SERCA1 and 2 protein expression), oxygen transport and diffusion (myoglobin) and redox regulation (Keap1). The glycolytic component can be predicted by the protein expression levels of pSer40-Nrf2, the maximal accumulated oxygen deficit and the protein expression levels of SOD1. Thus, an increased capacity to modulate the expression of antioxidant proteins involved in RONS handling and calcium homeostasis may be critical for performance during high-intensity exercise in humans.

Racial Differences in Blood Pressure and Autonomic Recovery Following Acute Supramaximal Exercise in Women.

Despite the growing popularity of high-intensity anaerobic exercise, little is known about the acute effects of this form of exercise on cardiovascular hemodynamics or autonomic modulation, which might provide insight into the individual assessment of responses to training load. The purpose of this study was to compare blood pressure and autonomic recovery following repeated bouts of acute supramaximal exercise in Black and White women. A convenience sample of twelve White and eight Black young, healthy women were recruited for this study and completed two consecutive bouts of supramaximal exercise on the cycle ergometer with 30 min of recovery in between. Brachial and central aortic blood pressures were assessed by tonometry (SphygmoCor Xcel) at rest and 15-min and 30-min following each exercise bout. Central aortic blood pressure was estimated using brachial pressure waveforms and customized software. Autonomic modulation was measured in a subset of ten participants by heart-rate variability and baroreflex sensitivity. Brachial mean arterial pressure and diastolic blood pressure were significantly higher in Blacks compared to Whites across time (race effect, p = 0.043 and p = 0.049, respectively). Very-low-frequency and low-frequency bands of heart rate variability, which are associated with sympathovagal balance and vasomotor tone, were 22.5% and 24.9% lower, respectively, in Blacks compared to Whites (race effect, p = 0.045 and p = 0.006, respectively). In conclusion, the preliminary findings of racial differences in blood pressure and autonomic recovery following supramaximal exercise warrant further investigations of tailored exercise prescriptions for Blacks and Whites.

An Examination and Critique of Subjective Methods to Determine Exercise Intensity: The Talk Test, Feeling Scale, and Rating of Perceived Exertion.

Prescribing exercise intensity is crucial in achieving an adequate training stimulus. While numerous objective methods exist and are used in practical settings for exercise intensity prescription, they all require anchor measurements that are derived from a maximal or submaximal graded exercise test or a series of submaximal or supramaximal exercise bouts. Conversely, self-reported subjective methods such as the Talk Test (TT), Feeling Scale (FS) affect rating, and rating of perceived exertion (RPE) do not require exercise testing prior to commencement of the exercise training and therefore appear as more practical tools for exercise intensity prescription. This review is intended to provide basic information on reliability and construct validity of the TT, FS, and RPE measurements to delineate intensity domains. The TT and RPE appear to be valid measures of both the ventilatory threshold and the respiratory compensation threshold. Although not specifically examined, the FS showed tendency to demarcate ventilatory threshold, but its validity to demarcate the respiratory compensation threshold is limited. Equivocal stage of the TT, RPE of 10-11, and FS ratings between fairly good (+ 1) and good (+ 3) are reflective of the ventilatory threshold, while negative stage of the TT, RPE of 13-15, and FS ratings around neutral (0) are reflective of the respiratory compensation threshold. The TT and RPE can effectively be used to elicit homeostatic disturbances consistent with the moderate, heavy, and severe intensity domains, while physiological responses to constant FS ratings show extensive variability around ventilatory threshold to be considered effective in demarcating transition between moderate and heavy intensity domains.

Recent Developments in the Use of Sodium Bicarbonate as an Ergogenic Aid.

This review examines the current status of sodium bicarbonate as an ergogenic aid. It builds on previous reviews in the area. Current research would suggest that as an ergogenic aid, a 300 mg·kg dose of NaHCO3 can improve high-intensity exercise, within a range of exercise modalities, such as a single bout of supramaximal exercise, high-intensity intermittent activity, and skill-based sports. In particular, these benefits seem to be present to a greater extent within trained individuals. Despite this, there appears to exist a high intraindividual variability in response to NaHCO3, and therefore, the ergogenic benefits may not be induced during every exercise bout. Current thinking also suggests that athletes need to individualize their ingestion timings to maximize peak pH or blood bicarbonate to effectively maximize the performance effect, and this may allow individuals to attain the ergogenic benefits of NaHCO3 more consistently.

High-CHO diet increases post-exercise oxygen consumption after a supramaximal exercise bout

We investigated if carbohydrate (CHO) availability could affect the excess post-exercise oxygen consumption (EPOC) after a single supramaximal exercise bout. Five physically active men cycled at 115% of peak oxygen uptake (V̇O2 peak) until exhaustion with low or high pre-exercise CHO availability. The endogenous CHO stores were manipulated by performing a glycogen-depletion exercise protocol 48 h before the trial, followed by 48 h consuming either a low- (10% CHO) or a high-CHO (80% CHO) diet regime. Compared to the low-CHO diet, the high-CHO diet increased time to exhaustion (3.0±0.6 min vs 4.4±0.6, respectively, P=0.01) and the total O2 consumption during the exercise (6.9±0.9 L and 11.3±2.1, respectively, P=0.01). This was accompanied by a higher EPOC magnitude (4.6±1.8 L vs 6.2±2.8, respectively, P=0.03) and a greater total O2 consumption throughout the session (exercise+recovery: 11.5±2.5 L vs 17.5±4.2, respectively, P=0.01). These results suggest that a single bout of supramaximal exercise performed with high CHO availability increases both exercise and post-exercise energy expenditure.

Effects of semi-rigid ankle orthoses on tasks related to athletic performance following a bout of fatiguing exercise

Despite the perceived protection of semi-rigid ankle orthoses (SRAO), coaches and clinicians are often concerned with the restriction that the SRAO may pose on functional performance. The purpose of this study was to determine the effect of SRAO on performance-selected tasks, following fatiguing activity. Twenty active, college-age subjects (22.7 ± 1.2 years; weight 71.7 ± 13.0 kg; height 171.7 ± 9.4 cm), without lower extremity trauma within 2 years, consented participation. Randomized trials for balance (star excursion balance test (SEBT)), agility (shuttle run (SR)), and power (vertical jump (VJ)) were compared between 4 conditions [fatigued, braced (FB); fatigued, un-braced (FUB); non-fatigued, braced (NFB); non-fatigued, un-braced (NFUB)]. Participants were bilaterally fitted with a well-known, commercially available SRAO for all braced trials. Two Wingate supramaximal exercise bouts were used as the fatiguing protocol. RMANOVA was performed for each functional test to determine main effects (SPSS, IL; α = 0.05 for all tests). No main effects for VJ & SR were observed under any of the bracing conditions. Main effect for bracing was observed for the SEBT. Tukey pairwise comparisons revealed that there were significant increases in distance reached for the posterior-medial direction (NFB = 0.91 cm ± 0.2; FB = 0.95 ± 0.2; p = 0.046) and medial direction (NFB = 0.74 cm ± 0.1; FB = 0.79 ± 0.1; p = 0.039) during the braced conditions. Although subjects reported that the SRAO restricted ROM during most SEBT directions involving inversion and eversion, overall performance was not hindered by the application of the brace. Further, the only main effects observed with functional performance involved increases in SEBT that could likely be attributed to comfort and confidence of motion while wearing an ankle device. It was concluded that articulated SRAO effectively limits ankle mobility, but does not appear to hinder athletic performance following a fatiguing bout.

Effects of Repeated Bouts of Supramaximal Exercise on Plasma Adiponectin, Interleukin-6, and Tumor Necrosis Factor-α Levels in Sedentary Men

The objective of the study was to determine the effects of repeated bouts of supramaximal exercise on plasma adiponectin, interleukin (IL)-6 and tumor necrosis factor (TNF)-α levels in sedentary men. Fourteen healthy, nonsmoking, and sedentary men aged between 18.4 and 21.4 years participated in the study. All the subjects performed 5 Wingate tests (WTs) with 75 g per kilogram body weight load with 2-minute intervals between the tests. Blood samples were collected at preexercise, immediately after, 15 and 60 minutes after the fifth WT. Serum and plasma samples were stored at -80°C until the time of analysis for myoglobin, adiponectin, IL-6, and TNF-α. Plasma adiponectin levels decreased, whereas IL-6 levels increased postexercise compared with that preexercise. The TNF-α levels were not changed with supramaximal exercise. In conclusion, repeated bouts of supramaximal exercise cause an inflammatory response in exercised muscle and increase in plasma IL-6 levels and decrease in adiponectin concentrations.

The physiological effects of low-intensity neuromuscular electrical stimulation (NMES) on short-term recovery from supra-maximal exercise bouts in male triathletes

This study investigated the acute effects of NMES on blood lactate (BLa) and performance parameters in trained male triathletes. On three separate days, 13 trained male triathletes performed six 30 s Wingate tests (30 WanT) on a cycle ergometer. Each session consisted of performing 3 × 30 WanT (bouts 1-3) followed by a randomly assigned 30 min recovery intervention of either: (i) passive (seated), (ii) active (cycling at 30% VO(2 max)) or (iii) NMES (1 Hz/500 μs-ON:OFF 2:6 s). The 3 × 30 WanT bouts were then repeated (bouts 4-6) and compared to bouts 1-3 for peak power (PP), mean power (MP) and fatigue index (FI). BLa and heart rate (HR) were recorded at designated time points throughout. Data were analyzed using repeated measures ANOVA with Tukey's honestly significant difference post hoc test. BLa decreased significantly faster during the active recovery intervention (P < 0.001), however, there were no significant differences between interventions for PP (P = 0.217), MP (P = 0.477) and FI (P = 0.234) when the post intervention bouts (4-6) where compared to the pre intervention bouts (1-3). NMES during recovery was not more effective than active or passive recovery for improving subsequent performance. Despite BLa clearing at a significantly faster rate for the active recovery intervention, PP, MP or FI did not improve significantly compared to NMES and passive. In conclusion, NMES does not appear to be more effective than traditional methods for enhancing short-term recovery from supra-maximal exercise bouts in trained male triathletes.

CSM 2011 Sports Physical Therapy Section Poster Presentations (Abstracts SPO2175–SPO2193)

CSM 2011 Sports Physical Therapy Section Poster Presentations (Abstracts SPO2175–SPO2193)

The Maximal Accumulated Oxygen Deficit Method

The maximal accumulated oxygen deficit (MAOD) method has been extensively, but unfortunately not very methodically, used; the procedure used to determine the MAOD varies considerably. Therefore, this review evaluates the effect of different numbers and durations of submaximal exercise bouts on the linear power output (PO)-oxygen uptake ((.)VO2) relationship and thus the MAOD. Changing the number and duration of the submaximal exercise bouts substantially influences the calculated MAOD when relatively long submaximal exercise bouts are used and no fixed value of the y-intercept is forced into the linear regression line. This is most likely due to non-linearity of the PO-(.)VO2 relationship for exercise intensities above the lactate threshold (LT). Non-linearity of the PO-(.)VO2 relationship is probably caused by the development of a slow component in (.)VO2 during submaximal exercise at intensities above the LT. Thus, it is important to standardize the number, duration and intensity of submaximal exercise bouts necessary to establish the PO-(.)VO2 relationship. Beyond changing the number and duration of the submaximal exercise bouts, the effect of different supramaximal exercise bouts on the calculated MAOD has been investigated. While it has become clear that different exercise protocols result in relatively similar values of the MAOD, a closer look at individual data suggests that it may be important to choose an exercise protocol that is representative of the athlete's event. The validity of the MAOD method was studied by different authors comparing the MAOD with metabolic measurements of anaerobic adenosine triphosphate (ATP) production. The main limitation with the metabolic measurements of anaerobic ATP production from muscle biopsy data is that the active muscle mass is unknown, which makes it hard to accurately study the validity of the MAOD method. From the studies that evaluated the reliability of the MAOD method it is clear that the MAOD method may not be a reliable measure of anaerobic capacity. From these findings it can be concluded that the MAOD method may have limitations as a valid and reliable measure of anaerobic capacity and needs to be further improved. We suggest the use of 10 x 4 minute submaximal exercise bouts and a fixed value of the y-intercept for the construction of the linear PO-(.)VO2 relationship, after which the MAOD can be determined during a supramaximal exercise protocol specific for the athlete's event. This method will lead to a more robust PO-(.)VO2 relationship and will therefore result in more valid and reliable results.

The Effects Of Coenzyme Q10 Supplementation on Performance During Repeated Bouts of Supramaximal Exercise in Sedentary Men

The objective of this study was to determine the effects of oral coenzyme Q10 (CoQ10) supplementation on performance during repeated bouts of supramaximal exercise. This randomized, double-blind, crossover study was composed of two 8-week periods of supplementation with either 100 mg.d(-1) CoQ10 or placebo. Fifteen healthy and sedentary men participated in the study. Five Wingate tests (WTs) with 75 g.kg(-1) body weight load with 2-minute intervals between tests were performed 3 times at baseline, after CoQ10, or placebo supplementation during the study period. Peak power (PP), mean power (MP), and fatigue index were calculated. During the 5 WTs, PP and MP tended to decrease and fatigue index tended to increase in all groups (p < 0.05). Peak power decreased with CoQ10 and placebo supplementation during the WT1, WT2, and WT2 (p < 0.05). Mean power increased only with CoQ10 supplementation during the WT5. Fatigue indexes decreased with CoQ10 supplementation, but these decreases did not differ from that seen with placebo supplementation. According to these results, CoQ10 may show performance-enhancing effects during the repeated bouts of supramaximal exercises and CoQ10 might be used as ergogenic aid.

Influence of Work-Interval Intensity and Duration on Time Spent at a High Percentage of JOURNAL/jscr/04.03/00124278-200912000-00017/OV0312_5/v/2021-02-09T093646Z/r/image-png O2max During Intermittent Supramaximal Exercise

The purpose of this study was to examine the effect of work-interval duration (WID) and intensity on the time spent at, or above, 95% VO2max (T95 VO2max) during intermittent bouts of supramaximal exercise. Over a 5-week period, 7 physically active men with a mean (+/-SD) age, height, body mass, and VO2max of 22 +/- 5 years, 181.5 +/- 5.6 cm, 86.4 +/- 11.4 kg, and 51.5 +/- 1.5 ml.kg-1.min-1, respectively, attended 7 testing sessions. After completing a submaximal incremental test on a treadmill to identify individual oxygen uptake/running velocity relationships, subjects completed a maximal incremental test to exhaustion to VO2max and subsequently (from the aforementioned relationship) the minimum velocity required to elicit VO2max (vVO2max). In a random order, subjects then carried out 3 intermittent runs to exhaustion at both 105% and 115% vVO2max. Each test used a different WID (20 s, 25 s, or 30 s) interspersed with 20-second passive recovery periods. Results revealed no significant difference in T95 vVO2max for intermittent runs at 105% versus 115% vVO2max (p = 0.142). There was, however, a significant effect (p < 0.001) of WID on T95 VO2max, with WIDs of 30 seconds enabling more time relative to WIDs of 20 seconds (p = 0.018) and 25 seconds (p = 0.009). Moreover, there was an interaction between intensity and duration such that the effect of WID was magnified at the lower exercise intensity (p = 0.046). In conclusion, despite a number of limitations, the results of this investigation suggest that exercise intensities of approximately 105% vVO2max combined with WIDs greater than 25 seconds provide the best way of optimizing T95 VO2max when using fixed 20-second stationary rest periods.

Heart rate variability and nonlinear analysis of heart rate dynamics following single and multiple Wingate bouts

Sprint interval training involves short bouts of high-intensity exercise and has produced training responses similar to those of endurance training. The effects of multiple supramaximal exercise bouts on neurocardiac modulation have not been examined. Therefore, we investigated the recovery of heart rate (HR) variability and nonlinear HR dynamics in 10 young (20.1 +/- 1.2 years) healthy males following single (1) and multiple (4) Wingate tests. HR variability was assessed with time and frequency domain measures, whereas nonlinear HR dynamics were determined by assessing the complexity (sample entropy) and fractal nature (detrended fluctuation analysis) of the HR time series. Responses were determined at pre-exercise baseline and at 3 time points during recovery from exercise: Post1 (5-20 min), Post2 (45-60 min), and Post3 (105-120 min). Following a single Wingate test, all temporal and spectral HR measures had returned to baseline by 1 h of recovery. In contrast, these measures were different from baseline at 2 h following multiple Wingate tests. Fractal HR properties were altered (p < 0.05) at Post1 following a single Wingate test and at Post1 and Post2 following multiple Wingate tests. HR complexity was reduced (p < 0.001) throughout the 2-h recovery following both exercise conditions. In conclusion, Wingate tests result in alterations in cardiac autonomic control, with multiple Wingate tests resulting in larger, more prolonged alterations. Based on the results of the single Wingate test, nonlinear measures, such as HR complexity, may be more sensitive in detecting subtle alterations in neurocardiac behaviour, compared with traditional measures of HR variability.

Effects of petrissage massage on fatigue and exercise performance following intensive cycle pedalling

Objective:Petrissage is assumed to influence circulation as well as interstitial drainage of both superficial and deep tissues. To study its effect it was applied between consecutive bouts of supramaximal exercise...

Pre-Exercise Alkalosis and Acid-Base Recovery

The aim of this study was to observe the influence of pre-exercise sodium bicarbonate (NaHCO3) ingestion and varying recovery modes on acid-base recovery from a single bout of supramaximal exercise. Nine male subjects completed four separate, randomized cycle ergometer exercise trials to volitional fatigue at 120% maximum power output, under the following conditions: 0.3 g.kg(-1) BW NaHCO3 ingestion with passive recovery (BICARB P), 0.3 g.kg (-1) BW NaHCO3 ingestion with active recovery (BICARB A), placebo ingestion with passive recovery (PLAC P) and placebo ingestion with active recovery (PLAC A). Capillary blood samples were obtained every minute for 15 min during recovery. Significant main effects for pH were observed for time (F = 42.1, p < 0.001), intervention (BICARB and PLAC) (F = 1117.3, p < 0.001) and recovery condition (F = 150.0, p < 0.001), as the BICARB condition reduced acid-base perturbation. Significant interaction effects were observed between conditions (BICARB and PLAC) for active and passive recovery modes (F = 29.1, p < 0.001) as the active recovery facilitated H+ removal better than the passive condition. Pre-exercise alkalosis attenuates blood acid-base perturbations from supramaximal exercise to exhaustion, regardless of whether the recovery mode is active or passive. These findings suggest that individuals may benefit from introducing a pre-exercise alkalotic condition while including passive recovery during high-intensity training protocols.

Haemodynamic responses following intermittent supramaximal exercise in athletes.

We aimed to investigate haemodynamics during active and passive recovery following repeated bouts of supramaximal exercise. Seven male athletes underwent two sessions of supramaximal exercise which consisted of a warm-up and of five bouts of cycling at the maximum speed possible for 30 s against a resistance equivalent to 150% of the maximum workload achieved in a previous incremental test. Bouts were separated by 1 min of recovery and followed by 10 min of recovery which was either active (pedalling at 40 W) or passive (completely rest seated on the cycle). Haemodynamic variables were evaluated by means of impedance cardiography. Heart rate (HR), stroke volume (SV), cardiac output (CO), mean blood pressure (MBP), thoracic electrical impedance (Z0) as an inverse index of central blood volume, and systemic vascular resistance (SVR) were assessed. The main findings were that active recovery, with respect to passive recovery, induced higher changes from baseline in HR (+29.1 +/- 4.5 versus +15.6 +/- 2.9 beats min(-1) at the 10th minute of recovery, P < 0.05), SV (+19.9 +/- 5.6 versus -6.4 +/- 3.3 ml, P < 0.01) and CO (+3.8 +/- 1.2 versus +0.4 +/- 0.2 l min(-1), P < 0.01). Furthermore, MBP was similar between the two kinds of recovery despite an increase in Z0 during passive compared to active recovery. These results suggest that the faster haemodynamic recovery towards baseline and the decrease in cardiac preload during passive recovery may be successfully prevented by cardiovascular regulatory mechanisms which include an increase in SVR, thus avoiding a drop in blood pressure.

Hemodynamics during active and passive recovery from a single bout of supramaximal exercise.

The aim of this work was to study the differences in cardiovascular response during two modes of recovery [active (AR): pedalling at 40 W; and passive (PR): complete rest seated] from a single bout of supramaximal exercise. Eight male amateur soccer players underwent two supramaximal cycle-ergometer tests, each consisting of pedalling against a resistance equivalent to 150% of the maximum workload achieved in a previous incremental test, followed by randomly assigned AR or PR. Cardiodynamic variables were obtained using an impedance cardiograph. Subjects were also connected to a sphygmomanometer, for systolic and diastolic blood pressure, and to a metabolimeter for oxygen uptake (VO(2)) assessments. We measured: heart rate (HR), stroke volume (SV), cardiac output (CO), the inverse of myocardial contractility calculated as pre-ejection period/left ventricular ejection time ratio (PEP/LVET), mean blood pressure (MBP), thoracic electrical impedance ( Z(0)) as an index of central blood volume, and arterio-venous oxygen difference (A-V O(2) Diff.). PR caused a lower CO compared to AR [mean (SE): 7 (0.7) vs. 10.4 (0.6) l.min(-1 )at the 5th min of recovery] due to lower HR [106.2 (3.6) vs. 121.8 (4.5) bpm at the 5th min of recovery], SV [67.1 (5) vs. 86.1 (4.8) ml at the 5th min of recovery], and PEP/VET values [0.44 (0.007) vs. 0.39 (0.015) at the 5th min of recovery]. No differences were found in MBP and Z(0) between PR and AR [95.1 (1.9) vs. 92.3 (2.7) mmHg and 26.2 (1.1) vs. 26.6 (1) Omega respectively at the 5th min of recovery], while A-V O(2) Diff. values were higher during AR than during PR [108.8 (4.3) vs. 75.2 (5.4) ml.l(-1) at the 5th min of recovery]. Thus, although after a single bout of supramaximal exercise SV and CO are lower during PR than during AR, these differences are not due to an impairment of cardiovascular function, but are fully explained by the lesser muscular engagement that leads to a reduction in stimuli deriving from mechanoreceptors and central commands, thus causing a faster return of myocardial contractility and HR to resting values.

ACTIVE RECOVERY BETWEEN HIGH-INTENSITY EXERCISE BOUTS IMPROVES PERFORMANCE IN HOCKEY PLAYERS

Background Active recovery (AR) compared to passive recovery (PR) between high-intensity exercise bouts increases total work achieved and promotes lactate clearance in hockey players. Previous studies applied AR via submaximal exercise sessions to reduce post-event fatigue. However, no study to date has applied AR between repeated supramaximal exercise bouts. Preliminary Data 6 sedentary subjects (4 male, 2 female) and 5 athletic subjects (3 male, 2 female) were tested to examine the effect of AR vs PR between consecutive 30-second supramaximal exercise bouts. Total work (joules) was higher in the athletic group than in the sedentary group (2871 vs. 1029; p < .02). Additionally, the data demonstrate a significant treatment effect of AR vs. PR (2127 vs. 1046; p < .02) as well as a significant interaction effect (p < .02). Thus AR, between supramaximal exercise bouts improves overall performance in normal subjects and athletes. Hypothesis AR between repetitive bouts of supramaximal activity in ice hockey players will result in greater performance as defined by total work achieved, and lactate clearance. Methods 3 amateur hockey players (3 male, mean age 26 ± 3 years, mean weight 83.5 ± 11.2 kg, mean VO2 max 45 ± 2.8 ml/O2/min) were tested. Each subject underwent three days of testing. Day 1 consisted of a baseline 30-second Wingate Power Test (WPT) on a Monark 818-E ergometer and baseline VO2 max testing on a Sensormedics electronically braked ergometer. On days 2 and 3, subjects were required to perform consecutive WPTs with a randomly-assigned 4-minute recovery period (AR at 28% of peak power, or PR) in between, until a 30% reduction in power occurred. Capillary lactate was taken when subjects reached a 30% reduction in power and every 5 minutes for 30 minutes after testing was completed. Results Means for total work achieved (joules) were 8646 with AR and 7151 with R, a significant difference (p < .021). In addition, capillary lactate levels (mmol) at the time of a 30% power reduction were 12.5 with AR, as compared to 15.8 with PR (p < .02). Conclusion This study is the first to document the dramatic beneficial effect of AR in between high-intensity exercise bouts in hockey players. Since the prevailing standard of recovery in ice hockey is PR, these results have potentially important implications in the recovery period between exercise bouts during a hockey game. Despite a small initial sample size, there is a significant effect of AR on performance, and currently further study is underway. The data also suggests that AR may be extremely valuable in sports where repetitive short bursts of high-intensity activity are required or in sports where muscle lactate accumulation may hinder performance. Supported by ACSM Reebok Grant for Human Performance and Injury Prevention 2000.

Effect of 6 weeks of endurance training on the lactate minimum speed

The aim of this study was to assess the sensitivity of the lactate minimum speed test to changes in endurance fitness resulting from a 6 week training intervention. Sixteen participants (mean +/- s :age 23 +/- 4 years;body mass 69.7 +/- 9.1 kg) completed 6 weeks of endurance training. Another eight participants (age 23 +/- 4 years; body mass 72.7 +/-12.5 kg) acted as non-training controls. Before and after the training intervention, all participants completed: (1) a standard multi-stage treadmill test for the assessment of VO 2max , running speed at the lactate threshold and running speed at a reference blood lactate concentration of 3 mmol.l -1 ; and (2) the lactate minimum speed test, which involved two supramaximal exercise bouts and an 8 min walking recovery period to increase blood lactate concentration before the completion of an incremental treadmill test. Additionally, a subgroup of eight participants from the training intervention completed a series of constant-speed runs for determination of running speed at the maximal lactate steady state. The test protocols were identical before and after the 6 week intervention. The control group showed no significant changes in VO 2max , running speed at the lactate threshold, running speed at a blood lactate concentration of 3 mmol.l -1 or the lactate minimum speed.In the training group, there was a significant increase in VO 2max (from 47.9 +/- 8.4 to 52.2 +/- 2.7 ml.kg -1 .min -1 ), running speed at the maximal lactate steady state (from 13.3 +/- 1.7 to 13.9 +/- 1.6 km.h -1 ), running speed at the lactate threshold (from 11.2 +/- 1.8 to 11.9 +/- 1.8 km.h -1 ) and running speed at a blood lactate concentration of 3 mmol.l -1 (from 12.5 +/- 2.2 to 13.2 +/- 2.1 km.h -1 ) (all P ≪ 0.05). Despite these clear improvements in aerobic fitness, there was no significant difference in lactate minimum speed after the training intervention (from 11.0 +/- 0.7 to 10.9 +/- 1.7 km.h -1 ). The results demonstrate that the lactate minimum speed,when assessed using the same exercise protocol before and after 6 weeks of aerobic exercise training, is not sensitive to changes in endurance capacity.

Blood lactate concentration and rated perceived exertion following active recovery in water

This investigation examined the effects of active water recovery (AWR) on blood lactate removal and perception of recovery following bouts of high intensity exercise. Six college‐aged males performed 3 × 45 s bouts of supramaximal treadmill sprinting (110% VO2max) followed by 20 min of passive recovery (PR), active treadmill recovery (ATR) or AWR. Subjects performed active recovery exercise at 29 ± 1.5% VO2max. Blood samples were collected immediately prior to exercise, 3 min following the final bout of supramaximal exercise and then every 2 min throughout recovery. Rating of perception of recovery was recorded immediately following ATR and AWR. Blood lactate was significantly lower (p ≤ 0.05) during AWR compared to PR beginning at 8 min of recovery and remained at a significantly reduced level throughout recovery. Similarly, blood lactate was lower during ATR compared with PR from 12 min of recovery until completion of the recovery session. Rating of perception of recovery was significantly lower following AWR (9.5 ±0.5 Borg Units) when compared with ATR (11.2 ±0.7 Borg Units). These results suggest that ATR and AWR are equally effective in enhancing blood lactate removal. However, AWR may provide a greater perception of recovery following high intensity, short duration exercise.