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Michael J. Saunders, Rebecca W. Moore, Arie K. Kies, Nicholas D. Luden and Casey A. Pratt

This study examined whether a carbohydrate + casein hydrolysate (CHO+ProH) beverage improved time-trial performance vs. a CHO beverage delivering ~60 g CHO/hr. Markers of muscle disruption and recovery were also assessed. Thirteen male cyclists (VO2peak = 60.8 ± 1.6 ml · kg−1 · min−1) completed 2 computer-simulated 60-km time trials consisting of 3 laps of a 20-km course concluding with a 5-km climb (~5% grade). Participants consumed 200 ml of CHO (6%) or CHO+ProH beverage (6% + 1.8% protein hydrolysate) every 5 km and 500 ml of beverage immediately postexercise. Beverage treatments were administered using a randomly counterbalanced, double-blind design. Plasma creatine phosphokinase (CK) and muscle-soreness ratings were assessed immediately before and 24 hr after cycling. Mean 60-km times were 134.4 ± 4.6 and 135.0 ± 4.0 min for CHO+ProH and CHO beverages, respectively. All time differences between treatments occurred during the final lap, with protein hydrolysate ingestion explaining a significant (p < .05) proportion of betweentrials differences over the final 20 km (44.3 ± 1.6, 45.0 ± 1.6 min) and final 5 km (16.5 ± 0.6, 16.9 ± 0.6 min). Plasma CK levels and muscle-soreness ratings increased significantly after the CHO trial (161 ± 53, 399 ± 175 U/L; 15.8 ± 5.1, 37.6 ± 5.7 mm) but not the CHO+ProH trial (115 ± 21, 262 ± 88 U/L; 20.9 ± 5.3, 32.2 ± 7.1 mm). Late-exercise time-trial performance was enhanced with CHO+ProH beverage ingestion compared with a beverage containing CHO provided at maximal exogenous oxidation rates during exercise. CHO+ProH ingestion also prevented increases in plasma CK and muscle soreness after exercise.

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Chelsea L. Oxendale, Craig Twist, Matthew Daniels and Jamie Highton

Purpose:

While exercise-induced muscle damage (EIMD) after rugby league match play has been well documented, the specific match actions that contribute to EIMD are unclear. Accordingly, the purpose of this study was to investigate the positional demands of elite rugby league matches and examine their relationship with subsequent EIMD.

Methods:

Twenty-eight performances (from 17 participants) were captured using 10-Hz global positioning systems over 4 competitive matches. Upper- and lower-body neuromuscular fatigue, creatine kinase (CK), and perceived muscle soreness were assessed 24 h before and at 12, 36, and 60 h after matches.

Results:

High-intensity running was moderately higher in backs (6.6 ± 2.6 m/min) than in forwards (5.1 ± 1.6 m/min), whereas total collisions were moderately lower (31.1 ± 13.1 vs 54.1 ± 37.0). Duration (r = .90, CI: .77–.96) and total (r = .86, CI: .70–.95) and high-intensity distance covered (r = .76, CI: .51–.91) were associated (P < .05) with increased CK concentration postmatch. Total collisions and repeated high-intensity efforts were associated (P < .05) with large decrements in upper-body neuromuscular performance (r = –.48, CI: –.74 to .02; r = –.49, CI: –.77 to .05, respectively), muscle soreness (r = –.68, CI: –.87 to –.10, r = –.66, CI: –.89 to .21, respectively), and CK concentration (r = .67, CI: .42–.85; r = .73, CI: .51–.87, respectively). All EIMD markers returned to baseline within 60 h.

Conclusion:

Match duration, high-intensity running, and collisions were associated with variations in EIMD markers, suggesting that recovery is dependent on individual match demands.

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Robin T. Thorpe, Anthony J. Strudwick, Martin Buchheit, Greg Atkinson, Barry Drust and Warren Gregson

Purpose:

To determine the sensitivity of a range of potential fatigue measures to daily training load accumulated over the previous 2, 3, and 4 d during a short in-season competitive period in elite senior soccer players (N = 10).

Methods:

Total highspeed-running distance, perceived ratings of wellness (fatigue, muscle soreness, sleep quality), countermovement-jump height (CMJ), submaximal heart rate (HRex), postexercise heart-rate recovery (HRR), and heart-rate variability (HRV: Ln rMSSD) were analyzed during an in-season competitive period (17 d). General linear models were used to evaluate the influence of 2-, 3-, and 4-d total high-speed-running-distance accumulation on fatigue measures.

Results:

Fluctuations in perceived ratings of fatigue were correlated with fluctuations in total high-speed-running-distance accumulation covered on the previous 2 d (r = –.31; small), 3 d (r = –.42; moderate), and 4 d (r = –.28; small) (P < .05). Changes in HRex (r = .28; small; P = .02) were correlated with changes in 4-d total high-speed-running-distance accumulation only. Correlations between variability in muscle soreness, sleep quality, CMJ, HRR%, and HRV and total high-speed-running distance were negligible and not statistically significant for all accumulation training loads.

Conclusions:

Perceived ratings of fatigue and HRex were sensitive to fluctuations in acute total high-speed-running-distance accumulation, although sensitivity was not systematically influenced by the number of previous days over which the training load was accumulated. The present findings indicate that the sensitivity of morning-measured fatigue variables to changes in training load is generally not improved when compared with training loads beyond the previous day’s training.

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Jay R. Ebert, Anne Smith, Peter K. Edwards and Timothy R. Ackland

Context:

Matrix-induced autologous chondrocyte implantation (MACI) is an established technique for the repair of knee chondral defects. Despite the reported clinical improvement in knee pain and symptoms, little is known on the recovery of knee strength and its return to an appropriate level compared with the unaffected limb.

Objective:

To investigate the progression of isokinetic knee strength and limb symmetry after MACI.

Design:

Prospective cohort.

Setting:

Private functional rehabilitation facility.

Patients:

58 patients treated with MACI for full-thickness cartilage defects to the femoral condyles.

Intervention:

MACI and a standardized rehabilitation protocol.

Main Outcome Measures:

Preoperatively and at 1, 2, and 5 y postsurgery, patients underwent a 3-repetition-maximum straight-leg raise test, as well as assessment of isokinetic knee-flexor and -extensor torque and hamstring:quadriceps (H:Q) ratios. Correlation analysis investigated the association between strength and pain, demographics, defect, and surgery characteristics. Linear-regression analysis estimated differences in strength measures between the operated and nonoperated limbs, as well as Limb Symmetry Indexes (LSI) over time.

Results:

Peak knee-extension torque improved significantly over time for both limbs but was significantly lower on the operated limb preoperatively and at 1, 2, and 5 y. Mean LSIs of 77.0%, 83.0%, and 86.5% were observed at 1, 2, and 5 y, respectively, while 53.4–72.4% of patients demonstrated an LSI ≤ 90% across the postoperative timeline. Peak knee-flexion torque was significantly lower on the operated limb preoperatively and at 1 year. H:Q ratios were significantly higher on the operated limb at all time points.

Conclusions:

While peak knee-flexion and hip-flexor strength were within normal limits, the majority of patients in this study still demonstrated an LSI for peak knee-extensor strength ≤ 90%, even at 5 y. It is unknown how this prolonged knee-extensor deficit may affect long-term graft outcome and risk of reinjury after return to activity.

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Armand E.O. Bettonviel, Naomi Y.J. Brinkmans, Kris Russcher, Floris C. Wardenaar and Oliver C. Witard

The nutritional status of elite soccer players across match, postmatch, training and rest days has not been defined. Recent evidence suggests the pattern of dietary protein intake impacts the daytime turnover of muscle proteins and, as such, influences muscle recovery. We assessed the nutritional status and daytime pattern of protein intake in senior professional and elite youth soccer players and compared findings against published recommendations. Fourteen senior professional (SP) and 15 youth elite (YP) soccer players from the Dutch premier division completed nutritional assessments using a 24-hr web-based recall method. Recall days consisted of a match, postmatch, rest, and training day. Daily energy intake over the 4-day period was similar between SP (2988 ± 583 kcal/day) and YP (2938 ± 465 kcal/day; p = .800). Carbohydrate intake over the combined 4-day period was lower in SP (4.7 ± 0.7 g·kg-1 BM·day-1) vs. YP (6.0 ± 1.5 g·kg-1 BM·day-1, p = .006) and SP failed to meet recommended carbohydrate intakes on match and training days. Conversely, recommended protein intakes were met for SP (1.9 ± 0.3 g·kg-1 BM·day-1) and YP (1.7 ± 0.4 g·kg-1 BM·day-1), with no differences between groups (p = .286). Accordingly, both groups met or exceeded recommended daily protein intakes on individual match, postmatch, rest and training days. A similar “balanced” daytime pattern of protein intake was observed in SP and YP. To conclude, SP increased protein intake on match and training days to a greater extent than YP, however at the expense of carbohydrate intake. The daytime distribution of protein intake for YP and SP aligned with current recommendations of a balanced protein meal pattern.

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Benita J. Lalor, Shona L. Halson, Jacqueline Tran, Justin G. Kemp and Stuart J. Cormack

Australian Football (AF) is an intermittent team sport involving rapid accelerations and decelerations, collisions, and large distances covered at a high intensity. 1 The competitive season can produce high levels of fatigue, and optimizing recovery in order to maximize performance is critical. 1

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Jonathan Magee, Ramón Spaaij and Ruth Jeanes

This paper builds on the concept of mental health recovery to critically examine three football projects in the United Kingdom and their effects on the recovery process. Drawing on qualitative research on the lived experiences of mental health clients and service providers across the three projects, we explore the role of football in relation to three components of recovery: engagement, stigma, and social isolation. The findings indicate how the projects facilitated increased client engagement, peer supports, and the transformation of self-stigma. The perception of football as an alternative setting away from the clinical environment was an important factor in this regard. Yet, the results also reveal major limitations, including the narrow, individualistic conceptualization of both recovery and stigma within the projects, the reliance on a biomedical model of mental illness, and the potentially adverse consequences of using football in mental health interventions.

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Ian McGinnis, Justin Cobb, Ryan Tierney and Anne Russ

recovery from concussion, both in athletic and general populations. 4 – 6 The vestibular system’s regulation of balance, spatial orientation, and gaze stability plays a key role in athletic tasks and many activities of daily living. Disruption of the vestibular system can exacerbate other symptoms of

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Brett S. Pexa, Eric D. Ryan, Elizabeth E. Hibberd, Elizabeth Teel, Terri Jo Rucinski and Joseph B. Myers

’s posterior shoulder to a high amount of eccentric muscle activity and causes significant trauma to the musculoskeletal system. Despite acute changes in CSA, 19 , 22 range of motion, 7 – 9 and glenohumeral strength, 23 there is still limited evidence defining the time to recovery of these variables

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David S. Rowlands, Rhys M. Thorp, Karin Rossler, David F. Graham and Mike J. Rockell

Carbohydrate ingestion after prolonged strenuous exercise enhances recovery, but protein might also be important. In a crossover with 2-wk washout, 10 cyclists completed 2.5 h of intervals followed by 4-h recovery feeding, provided 218 g protein, 435 g carbohydrate, and 79 g fat (protein enriched) or 34 g protein, 640 g carbohydrate, and 79 g fat (isocaloric control). The next morning, cyclists performed 10 maximal constant-work sprints on a Velotron cycle ergometer, each lasting ~2.5 min, at ~5-min intervals. Test validity was established and test reliability and the individual response to the protein-enriched condition estimated by 6 cyclists’ repeating the intervals, recovery feeding, and performance test 2 wk later in the protein-enriched condition. During the 4-h recovery, the protein-enriched feeding had unclear effects on mean concentrations of plasma insulin, cortisol, and growth hormone, but testosterone was 25% higher (90% confidence limits, ± 14%). Protein enrichment also reduced plasma creatine kinase by 33% (±38%) the next morning and reduced tiredness and leg-soreness sensations during the sprints, but effects on mean sprint power were unclear (–1.4%, ±4.3%). The between-subjects trial-to-trial coefficient of variation in overall mean sprint power was 3.1% (±3.4%), whereas the variation in the protein-enriched condition was 5.9% (±6.9%), suggesting that individual responses to the protein-enriched treatment contributed to the unclear performance outcome. To conclude, protein-enriched recovery feeding had no clear effect on next-day performance.