Search Results

You are looking at 1 - 10 of 11 items for

  • Author: Glyn Howatson x
Clear All Modify Search
Restricted access

Glyn Howatson, Raphael Brandon and Angus M. Hunter

There is a great deal of research on the responses to resistance training; however, information on the responses to strength and power training conducted by elite strength and power athletes is sparse.

Purpose:

To establish the acute and 24-h neuromuscular and kinematic responses to Olympic-style barbell strength and power exercise in elite athletes.

Methods:

Ten elite track and field athletes completed a series of 3 back-squat exercises each consisting of 4 × 5 repetitions. These were done as either strength or power sessions on separate days. Surface electromyography (sEMG), bar velocity, and knee angle were monitored throughout these exercises and maximal voluntary contraction (MVC), jump height, central activation ratio (CAR), and lactate were measured pre, post, and 24 h thereafter.

Results:

Repetition duration, impulse, and total work were greater (P < .01) during strength sessions, with mean power being greater (P < .01) after the power sessions. Lactate increased (P < .01) after strength but not power sessions. sEMG increased (P < .01) across sets for both sessions, with the strength session increasing at a faster rate (P < .01) and with greater activation (P < .01) by the end of the final set. MVC declined (P < .01) after the strength and not the power session, which remained suppressed (P < .05) 24 h later, whereas CAR and jump height remained unchanged.

Conclusion:

A greater neuromuscular and metabolic demand after the strength and not power session is evident in elite athletes, which impaired maximal-force production for up to 24 h. This is an important consideration for planning concurrent athlete training.

Restricted access

Ken A. van Someren and Glyn Howatson

Purpose:

To determine the relative importance of anthropometric and physiological attributes for performance in the 1000-m, 500-m, and 200-m flatwater kayaking events.

Methods:

Eighteen competitive male kayakers completed performance trials over the 3 distances and a battery of anthropometric and physiological tests.

Results:

Performance times (mean ± SD) for 1000 m, 500 m, and 200 m were 262.56 ± 36.44 s, 122.10 ± 5.74 s, and 41.59 ± 2.12 s, respectively. Performance in all 3 events was correlated with a number of physiological parameters; in addition, 500-m and 200-m performance was correlated with upper body dimensions. 1000-m time was predicted by power output at lactate turnpoint expressed as a percentage of maximal aerobic power, work done in a 30-s ergometry test and work done in a 2-min ergometry test (adjusted R 2 = 0.71, SEE = 5.72 s); 500-m time was predicted by work done and the fatigue index in a 30-s ergometry test, work done in a 2-min ergometry test, peak isometric and isokinetic function (adjusted R 2 = 0.79, SEE = 2.49 s); 200-m time was predicted by chest circumference, humeral breadth, peak power, work done, and the fatigue index in a 30-s ergometry test (adjusted R 2 = 0.71, SEE = 0.71 s).

Conclusions:

A number of physiological variables are correlated with performance in all events. 1000-m, 500-m, and 200-m times were predicted with a standard error of only 2.2%, 2.0%, and 1.7%, respectively.

Restricted access

Ken A. van Someren, Adam J. Edwards and Glyn Howatson

This study examined the effects of β-hydroxy-β-methylbutyrate (HMB) and α-ketoisocaproic acid (KIC) supplementation on signs and symptoms of exercise-induced muscle damage following a single bout of eccentrically biased resistance exercise. Six non-resistance trained male subjects performed an exercise protocol designed to induce muscle damage on two separate occasions, performed on the dominant or non-dominant arm in a counter-balanced crossover design. Subjects were assigned to an HMB/KIC (3 g HMB and 0.3 g α-ketoisocaproic acid, daily) or placebo treatment for 14 d prior to exercise in the counter-balanced crossover design. One repetition maximum (1RM), plasma creatine kinase activity (CK), delayed onset muscle soreness (DOMS), limb girth, and range of motion (ROM) were determined pre-exercise, at 1h, 24 h, 48 h, and 72 h post-exercise. DOMS and the percentage changes in 1RM, limb girth, and ROM all changed over the 72 h period (P < 0.05). HMB/KIC supplementation attenuated the CK response, the percentage decrement in 1RM, and the percentage increase in limb girth (P < 0.05). In addition, DOMS was reduced at 24 h post-exercise (P < 0.05) in the HMB/KIC treatment. In conclusion, 14 d of HMB and KIC supplementation reduced signs and symptoms of exercise-induced muscle damage in non-resistance trained males following a single bout of eccentrically biased resistance exercise.

Restricted access

Javier T. Gonzalez, Martin J. Barwood, Stuart Goodall, Kevin Thomas and Glyn Howatson

Unaccustomed eccentric exercise using large muscle groups elicits soreness, decrements in physical function and impairs markers of whole-body insulin sensitivity; although these effects are attenuated with a repeated exposure. Eccentric exercise of a small muscle group (elbow flexors) displays similar soreness and damage profiles in response to repeated exposure. However, it is unknown whether damage to small muscle groups impacts upon whole-body insulin sensitivity. This pilot investigation aimed to characterize whole-body insulin sensitivity in response to repeated bouts of eccentric exercise of the elbow flexors. Nine healthy males completed two bouts of eccentric exercise separated by 2 weeks. Insulin resistance (updated homeostasis model of insulin resistance, HOMA2-IR) and muscle damage profiles (soreness and physical function) were assessed before, and 48 h after exercise. Matsuda insulin sensitivity indices (ISIMatsuda) were also determined in 6 participants at the same time points as HOMA2-IR. Soreness was elevated, and physical function impaired, by both bouts of exercise (both p < .05) but to a lesser extent following bout 2 (time x bout interaction, p < .05). Eccentric exercise decreased ISIMatsuda after the first but not the second bout of eccentric exercise (time x bout interaction p < .05). Eccentric exercise performed with an isolated upper limb impairs whole-body insulin sensitivity after the first, but not the second, bout.

Restricted access

Tom Clifford, Will Abbott, Susan Y. Kwiecien, Glyn Howatson and Malachy P. McHugh

Purpose : To examine whether donning lower-body garments fitted with cooled phase change material (PCM) would enhance recovery after a soccer match. Methods : In a randomized, crossover design, 11 elite soccer players from the reserve squad of a team in the second-highest league in England wore PCM cooled to 15°C (PCMcold) or left at ambient temperature (PCMamb; sham control) for 3 h after a soccer match. To assess recovery, countermovement jump height, maximal isometric voluntary contraction (MIVC), muscle soreness, and the adapted Brief Assessment of Mood Questionnaire (BAM+) were measured before 12, 36, and 60 h after each match. A belief questionnaire was completed preintervention and postintervention to determine the perceived effectiveness of each garment. Results : Results are comparisons between the 2 conditions at each time point postmatch. MIVC at 36 h postmatch was greater with PCMcold versus PCMwarm (P = .01; ES = 1.59; 95% CI, 3.9–17.1%). MIVC also tended to be higher at 60 h postmatch (P = .05; ES = 0.85; 95% CI, −0.4% to 11.1%). Muscle soreness was 26.5% lower in PCMcold versus PCMwarm at 36 h (P = .02; ES = 1.7; 95% CI, −50.4 to −16.1 mm) and 24.3% lower at 60 h (P = .04; ES = 1.1; 95% CI, −26.9 to −0.874 mm). There were no between-conditions differences in postmatch countermovement jump height or BAM+ (P > .05). The belief questionnaire revealed that players felt the PCMcold was more effective than the PCMamb after the intervention (P = .004). Conclusions : PCM cooling garments provide a practical means of delivering prolonged postexercise cooling and thereby accelerate recovery in elite soccer players.

Restricted access

Susan Y. Kwiecien, Malachy P. McHugh, Stuart Goodall, Kirsty M. Hicks, Angus M. Hunter and Glyn Howatson

Purpose: To evaluate the effectiveness between cold-water immersion (CWI) and phase-change-material (PCM) cooling on intramuscular, core, and skin-temperature and cardiovascular responses. Methods: In a randomized, crossover design, 11 men completed 15 min of 15°C CWI to the umbilicus and 2-h recovery or 3 h of 15°C PCM covering the quadriceps and 1 h of recovery, separated by 24 h. Vastus lateralis intramuscular temperature at 1 and 3 cm, core and skin temperature, heart-rate variability, and thermal comfort were recorded at baseline and 15-min intervals throughout treatment and recovery. Results: Intramuscular temperature decreased (P < .001) during and after both treatments. A faster initial effect was observed from 15 min of CWI (Δ: 4.3°C [1.7°C] 1 cm; 5.5°C [2.1°C] 3 cm; P = .01). However, over time (2 h 15 min), greater effects were observed from prolonged PCM treatment (Δ: 4.2°C [1.9°C] 1 cm; 2.2°C [2.2°C] 3 cm; treatment × time, P = .0001). During the first hour of recovery from both treatments, intramuscular temperature was higher from CWI at 1 cm (P = .013) but not 3 cm. Core temperature deceased 0.25° (0.32°) from CWI (P = .001) and 0.28°C (0.27°C) from PCM (P = .0001), whereas heart-rate variability increased during both treatments (P = .001), with no differences between treatments. Conclusions: The magnitude of temperature reduction from CWI was comparable with PCM, but intramuscular temperature was decreased for longer during PCM. PCM cooling packs offer an alternative for delivering prolonged cooling whenever application of CWI is impractical while also exerting a central effect on core temperature and heart rate.

Restricted access

Jessica Hill, Glyn Howatson, Ken van Someren, David Gaze, Hayley Legg, Jack Lineham and Charles Pedlar

Compression garments are frequently used to facilitate recovery from strenuous exercise.

Purpose:

To identify the effects of 2 different grades of compression garment on recovery indices after strenuous exercise.

Methods:

Forty-five recreationally active participants (n = 26 male and n = 19 female) completed an eccentric-exercise protocol consisting of 100 drop jumps, after which they were matched for body mass and randomly but equally assigned to a high-compression pressure (HI) group, a low-compression pressure (LOW) group, or a sham ultrasound group (SHAM). Participants in the HI and LOW groups wore the garments for 72 h postexercise; participants in the SHAM group received a single treatment of 10-min sham ultrasound. Measures of perceived muscle soreness, maximal voluntary contraction (MVC), countermovement-jump height (CMJ), creatine kinase (CK), C-reactive protein (CRP), and myoglobin (Mb) were assessed before the exercise protocol and again at 1, 24, 48, and 72 h postexercise. Data were analyzed using a repeated-measures ANOVA.

Results:

Recovery of MVC and CMJ was significantly improved with the HI compression garment (P < .05). A significant time-by-treatment interaction was also observed for jump height at 24 h postexercise (P < .05). No significant differences were observed for parameters of soreness and plasma CK, CRP, and Mb.

Conclusions:

The pressures exerted by a compression garment affect recovery after exercise-induced muscle damage, with higher pressure improving recovery of muscle function.

Restricted access

Geoff P. Lovell, John K. Parker, Abbe Brady, Stewart T. Cotterill and Glyn Howatson

Research has reported that initial evaluations of consultants’ competency are affected by dress and build. This investigation examined how athletes’ perceptions of sport psychology consultants (SPCs) are affected by SPCs’ physical characteristics of BMI and dress, and whether these perceptions are moderated by the athletes’ sex or standard of competition. Two hundred and thirty three competitive sports volunteers classified by sex and competitive standard viewed computer generated images of the same female SPC in sports and formal attire manipulated to represent a range of body mass indexes. Participants were asked to rank the SPCs in order of their preference to work with them, and to rate their perceived effectiveness of each of the SPCs. Results demonstrated that SPCs’ physical characteristics do influence athletes’ preference to work with them and perceptions of their effectiveness. Furthermore, athlete’s competitive standard does significantly moderate initial evaluation of SPCs based on physical characteristics.

Restricted access

Malachy P. McHugh, Tom Clifford, Will Abbott, Susan Y. Kwiecien, Ian J. Kremenic, Joseph J. DeVita and Glyn Howatson

Purpose: To assess the utility of an inertial sensor for assessing recovery in professional soccer players. Methods: In a randomized, crossover design, 11 professional soccer players wore shorts fitted with phase change material (PCM) cooling packs or uncooled packs (control) for 3 h after a 90-min match. Countermovement jump (CMJ) performance was assessed simultaneously with an inertial sensor and an optoelectric system: prematch and 12, 36, and 60 h postmatch. Inertial sensor metrics were flight height, jump height, low force, countermovement distance, force at low point, rate of eccentric force development, peak propulsive force, maximum power, and peak landing force. The only optoelectric metric was flight height. CMJ decrements and the effect of PCM cooling were assessed with repeated-measures analysis of variance. Jump heights were also compared between devices. Results: For the inertial sensor data, there were decrements in CMJ height on the days after matches (88% [10%] of baseline at 36 h, P = .012, effect size = 1.2, for control condition) and accelerated recovery with PCM cooling (105% [15%] of baseline at 36 h, P = .018 vs control, effect size = 1.1). Flight heights were strongly correlated between devices (r = .905, P < .001), but inertial sensor values were 1.8 [1.8] cm lower (P = .008). Low force during countermovement was increased (P = .031) and landing force was decreased (P = .043) after matches, but neither was affected by the PCM cooling intervention. Other CMJ metrics were unchanged after matches. Conclusions: This small portable inertial sensor provides a practical means of assessing recovery in soccer players.

Restricted access

Jonathan D.C. Leeder, Ken A. van Someren, David Gaze, Andrew Jewell, Nawed I.K. Deshmukh, Iltaf Shah, James Barker and Glyn Howatson

Purpose:

This investigation aimed to ascertain a detailed physiological profile of recovery from intermittentsprint exercise of athletes familiar with the exercise and to investigate if athletes receive a protective effect on markers of exercise-induced muscle damage (EIMD), inflammation, and oxidative stress after a repeated exposure to an identical bout of intermittent-sprint exercise.

Methods:

Eight well-trained male team-sport athletes of National League or English University Premier Division standard (mean ± SD age 23 ± 3 y, VO2max 54.8 ± 4.6 mL · kg−1 · min−1) completed the Loughborough Intermittent Shuttle Test (LIST) on 2 occasions, separated by 14 d. Maximal isometric voluntary contraction (MIVC), countermovement jump (CMJ), creatine kinase (CK), C-reactive protein (CRP), interleukin-6 (IL-6), F2-isoprostanes, and muscle soreness (DOMS) were measured before and up to 72 h after the initial and repeated LISTs.

Results:

MIVC, CMJ, CK, IL-6, and DOMS all showed main effects for time (P < .05) after the LIST, indicating that EIMD was present. DOMS peaked at 24 h after LIST 1 (110 ± 53 mm), was attenuated after LIST 2 (56 ± 39 mm), and was the only dependent variable to demonstrate a reduction in the second bout (P = .008). All other markers indicated that EIMD did not differ between bouts.

Conclusion:

Well-trained games players experienced EIMD after exposure to both exercise tests, despite being accustomed to the exercise type. This suggests that well-trained athletes receive a very limited protective effect from the first bout.