scholarly journals The effect of high‐intensity priming exercise on indices of aerobic function and exercise tolerance during a subsequent high‐intensity exercise bout

2006 ◽  
Vol 20 (4) ◽  
Author(s):  
Carrie Ferguson ◽  
Brian J Whipp ◽  
Andrew J Cathcart ◽  
Harry B Rossiter ◽  
Susan A Ward
Keyword(s):  
High Intensity ◽  
Exercise Tolerance ◽  
Exercise Bout ◽  
High Intensity Exercise ◽  
Aerobic Function ◽  
Priming Exercise

Pre-exercise β-hydroxy-β-methylbutyrate free-acid supplementation improves work capacity recovery: a randomized, double-blinded, placebo-controlled study

2018 ◽  
Vol 43 (7) ◽  
pp. 691-696 ◽  
Author(s):  
Ana Luiza Matias Correia ◽  
Filipe Dinato de Lima ◽  
Martim Bottaro ◽  
Amilton Vieira ◽  
Andrew Correa da Fonseca ◽  
...  
Keyword(s):  
Single Dose ◽  
High Intensity ◽  
Time Course ◽  
Free Acid ◽  
Exercise Bout ◽  
Work Capacity ◽  
High Intensity Exercise ◽  
Controlled Study ◽  
Exercise Protocol ◽  
Young Males

The purpose of this study was to investigate the effects of a single-dose of β-hydroxy-β-methylbutyrate free acid (HMB-FA) supplementation on muscle recovery after a high-intensity exercise bout. Twenty-three trained young males were randomly assigned to receive either a single-dose supplementation of 3 g of HMB-FA (n = 12; age, 22.8 ± 3.0 years) or placebo (PLA; n = 11; age, 22.9 ± 3.1 years). A muscle damage protocol was applied 60 min after supplementation, and consisted of 7 sets of 20 drop jumps from a 60-cm box with 2-min rest intervals between sets. Muscle swelling, countermovement jump (CMJ), maximal voluntary isometric torque (MVIT), and work capacity (WC) were measured before, immediately after, and 24, 48, and 72 h after the exercise protocol. Muscle swelling, CMJ, and MVIT changed similarly in both groups after the exercise protocol (p < 0.001), but returned to pre-exercise levels after 24 h in both groups. WC decreased similarly in both groups after the exercise protocol (p < 0.01). For HMB-FA, WC returned to pre-exercise level 24 h after exercise protocol. However, for PLA, WC did not return to pre-exercise level even 72 h after the exercise protocol. In summary, a single-dose of HMB-FA supplementation improved WC recovery after a high-intensity exercise bout. However, HMB-FA did not affect the time-course of muscle swelling, MVIT, and CMJ recovery.

Pulmonary O2 uptake kinetics as a determinant of high-intensity exercise tolerance in humans

2011 ◽  
Vol 110 (6) ◽  
pp. 1598-1606 ◽  
Author(s):  
Scott R. Murgatroyd ◽  
Carrie Ferguson ◽  
Susan A. Ward ◽  
Brian J. Whipp ◽  
Harry B. Rossiter
Keyword(s):  
Steady State ◽  
High Intensity ◽  
Exercise Tolerance ◽  
Slow Component ◽  
Progressive Increase ◽  
High Intensity Exercise ◽  
Exercise Intolerance ◽  
Exercise Onset ◽  
O2 Uptake Kinetics ◽  
Two Parameters

Tolerance to high-intensity constant-power (P) exercise is well described by a hyperbola with two parameters: a curvature constant (W′) and power asymptote termed “critical power” (CP). Since the ability to sustain exercise is closely related to the ability to meet the ATP demand in a steady state, we reasoned that pulmonary O2 uptake (V̇o2) kinetics would relate to the P-tolerable duration (tlim) parameters. We hypothesized that 1) the fundamental time constant (τV̇o2) would relate inversely to CP; and 2) the slow-component magnitude (ΔV̇o2sc) would relate directly to W′. Fourteen healthy men performed cycle ergometry protocols to the limit of tolerance: 1) an incremental ramp test; 2) a series of constant-P tests to determine V̇o2max, CP, and W′; and 3) repeated constant-P tests (WR6) normalized to a 6 min tlim for τV̇o2 and ΔV̇o2sc estimation. The WR6 tlim averaged 365 ± 16 s, and V̇o2max (4.18 ± 0.49 l/min) was achieved in every case. CP (range: 171–294 W) was inversely correlated with τV̇o2 (18–38 s; R2 = 0.90), and W′ (12.8–29.9 kJ) was directly correlated with ΔV̇o2sc (0.42–0.96 l/min; R2 = 0.76). These findings support the notions that 1) rapid V̇o2 adaptation at exercise onset allows a steady state to be achieved at higher work rates compared with when V̇o2 kinetics are slower; and 2) exercise exceeding this limit initiates a “fatigue cascade” linking W′ to a progressive increase in the O2 cost of power production (V̇o2sc), which, if continued, results in attainment of V̇o2max and exercise intolerance. Collectively, these data implicate V̇o2 kinetics as a key determinant of high-intensity exercise tolerance in humans.

scholarly journals The effects of a high-intensity exercise bout on landing biomechanics post anterior cruciate ligament reconstruction: a quasi-experimental study

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ahmad Dhahawi Alanazi ◽  
Katy Mitchell ◽  
Toni Roddey ◽  
Aqeel M. Alenazi ◽  
Msaad M. Alzhrani ◽  
...  
Keyword(s):  
High Intensity ◽  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Exercise Bout ◽  
High Intensity Exercise ◽  
Soccer Players ◽  
Cruciate Ligament Reconstruction ◽  
Landing Biomechanics ◽  
Ankle Joints ◽  
Anterior Cruciate

Abstract Background We aimed to examine the effect of a high-intensity exercise bout on landing biomechanics in soccer players who underwent anterior cruciate ligament reconstruction (ACLR) and non-injured soccer players during a soccer-specific landing maneuver. Methods Eighteen soccer players who underwent ACLR and 18 normal soccer players were enrolled in this investigation (ACLR group; age, 26.11 ± 3.95 years; body mass index, 23.52 ± 2.69 kg/m2; surgery time, 5 ± 3.30 years: control group; age, 25.83 ± 3.51 years; body mass index, 24.09 ± 3.73 kg/m2, respectively). Participants were evaluated during the landing maneuver before and after carrying out the high-intensity exercise bout using the Wingate test. The intensity of the exercise was defined as a blood lactate accumulation of at least 4 mmol/L. The dependent variables included sagittal-plane kinematics and kinetics of the ankle, knee and hip joints, and electromyography activity of the gastrocnemius, hamstrings, quadriceps, and gluteus maximus. Results On 2 × 2 analysis of variance, none of the dependent variable showed significant exercise×group interactions. Regardless of group, significant main effects of exercise were found. Post-exercise landing was characterized by increased flexion of hip (p = 0.01), knee (p = 0.001), and ankle joints (p = 0.002); increased extension moments of hip (p = 0.009), knee (p = 0.012), and ankle joints (p = 0.003), as well as decreased quadriceps activity (p = 0.007). Conclusion At 1 year or more post-ACLR, the effect of the high-intensity exercise bout on landing biomechanics is not expected to differ from that experienced by healthy soccer players.

Caffeine, performance, and metabolism during repeated Wingate exercise tests

1998 ◽  
Vol 85 (4) ◽  
pp. 1502-1508 ◽  
Author(s):  
F. Greer ◽  
C. McLean ◽  
T. E. Graham
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Anaerobic Metabolism ◽  
Exercise Bout ◽  
High Intensity Exercise ◽  
Intense Exercise ◽  
Short Term ◽  
Exercise Tests ◽  
Negative Effect ◽  
Epinephrine Concentration

Investigations examining the ergogenic and metabolic influence of caffeine during short-term high-intensity exercise are few in number and have produced inconsistent results. This study examined the effects of caffeine on repeated bouts of high-intensity exercise in recreationally active men. Subjects ( n = 9) completed four 30-s Wingate (WG) sprints with 4 min of rest between each exercise bout on two separate occasions. One hour before exercise, either placebo (Pl; dextrose) or caffeine (Caf; 6 mg/kg) capsules were ingested. Caf ingestion did not have any effect on power output (peak or average) in the first two WG tests and had a negative effect in the latter two exercise bouts. Plasma epinephrine concentration was significantly increased 60 min after Caf ingestion compared with Pl; however, this treatment effect disappeared once exercise began. Caf ingestion had no significant effect on blood lactate, O2 consumption, or aerobic contribution at any time during the protocol. After the second Wingate test, plasma NH3concentration increased significantly from the previous WG test and was significantly higher in the Caf trial compared with Pl. These data demonstrate no ergogenic effect of caffeine on power output during repeated bouts of short-term, intense exercise. Furthermore, there was no indication of increased anaerobic metabolism after Caf ingestion with the exception of an increase in NH3 concentration.

Glucose Tolerance Is Improved After Low- and High-Intensity Exercise in Middle-Age Men and Women

1998 ◽  
Vol 23 (6) ◽  
pp. 583-593 ◽  
Author(s):  
Arend Bonen ◽  
Margaret Ball-Burnett ◽  
Caryl Russel
Keyword(s):  
Glucose Tolerance ◽  
High Intensity ◽  
Area Under The Curve ◽  
Exercise Bout ◽  
Tolerance Test ◽  
High Intensity Exercise ◽  
Oral Glucose ◽  
Oral Glucose Tolerance ◽  
Beneficial Effects ◽  
Low Intensity Exercise

We compared the effects of low- and high-intensity exercise on oral glucose tolerance immediately and 24 hr after each exercise bout. Participants were 5 male and 5 female individuals (age 40-48). A fasted, oral glucose tolerance test (OGTT) was conducted several days before the first exercise bout. Glucose and insulin concentrations were determined every 15 min throughout a 2 hr, 75 g OGTT. Immediately after low-intensity exercise, the incremental glucose area under the curve was reduced by 16%, compared to the fasting OGTT (p < .05). This was reduced further (−30%) 24 hr postexercise (p < .05). After high-intensity exercise, similar results were observed, with the incremental glucose area reduced by 14 and 35% immediately and 24 hr postexercise, respectively (p < .05). In conclusion, exercise improves glucose tolerance, this effect is more pronounced 24 hr postexercise, and low-and high-intensity exercise provide similar beneficial effects on glucose tolerance. Key words: cycle ergometry, insulin

Effects of prior very-heavy intensity exercise on indices of aerobic function and high-intensity exercise tolerance

2007 ◽  
Vol 103 (3) ◽  
pp. 812-822 ◽  
Author(s):  
C. Ferguson ◽  
B. J. Whipp ◽  
A. J. Cathcart ◽  
H. B. Rossiter ◽  
A. P. Turner ◽  
...  
Keyword(s):  
High Intensity ◽  
Slow Component ◽  
Energy Resource ◽  
Constant Load ◽  
High Intensity Exercise ◽  
Metabolite Level ◽  
Fully Depleted ◽  
Significant Difference ◽  
Aerobic Function ◽  
Residual Fatigue

A recent bout of high-intensity exercise can alter the balance of aerobic and anaerobic energy provision during subsequent exercise above the lactate threshold (θL). However, it remains uncertain whether such “priming” influences the tolerable duration of subsequent exercise through changes in the parameters of aerobic function [e.g., θL, maximum oxygen uptake (V̇o2max)] and/or the hyperbolic power-duration (P-t) relationship [critical power (CP) and the curvature constant (W′)]. We therefore studied six men performing cycle ergometry to the limit of tolerance; gas exchange was measured breath-by-breath and arterialized capillary blood [lactate] was measured at designated intervals. On different days, each subject completed 1) an incremental test (15 W/min) for estimation of θL and measurement of the functional gain (ΔV̇o2/ΔWR) and V̇o2peak and 2) four constant-load tests at different work rates (WR) for estimation of CP, W′, and V̇o2max. All tests were subsequently repeated with a preceding 6-min supra-CP priming bout and an intervening 2-min 20-W recovery. The hyperbolicity of the P-t relationship was retained postpriming, with no significant difference in CP (241 ± 39 vs. 242 ± 36 W, post- vs. prepriming), V̇o2max (3.97 ± 0.34 vs. 3.93 ± 0.38 l/min), ΔV̇o2/ΔWR (10.7 ± 0.3 vs. 11.1 ± 0.4 ml·min−1·W−1), or the fundamental V̇o2 time constant (25.6 ± 3.5 vs. 28.3 ± 5.4 s). W′ (10.61 ± 2.07 vs. 16.13 ± 2.33 kJ) and the tolerable duration of supra-CP exercise (−33 ± 11%) were each significantly reduced, despite a less-prominent V̇o2 slow component. These results suggest that, following supra-CP priming, there is either a reduced depletable energy resource or a residual fatigue-metabolite level that leads to the tolerable limit before this resource is fully depleted.

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