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Helena Gapeyeva, Mati Pääsuke, Jaan Ereline, Vallo Vaher, Aivar Pintsaar and Aalo Eller

Context:

Contractile characteristics of the knee extensors after arthroscopic meniscectomy are poorly understood.

Objective:

To measure the recovery of knee-extensor-muscle contractility after arthroscopic partial meniscectomy.

Design:

Single-group repeated measures.

Setting:

Kinesiology and biomechanics laboratory.

Subjects:

Fourteen patients with arthroscopic partial medial meniscectomies.

Main Outcome Measures:

Maximal isometric voluntary contraction (MVC) force, rate of force development (MRFDES), and half-relaxation time (HRTES) of evoked tetanic contraction preoperatively and during 6 months postoperatively.

Results:

Two weeks postoperatively, a reduction in MVC force of 27.1% and in MRFDES of 17.8% and a prolongation of HRTES of 34.0% in the injured leg were found. A significant MVC-force deficit (17.5%) was observed 3 months postoperatively.

Conclusions:

The recovery of knee-extensor-muscle voluntary strength is more delayed than are evoked tetanic-contractile characteristics after partial meniscectomy. The rehabilitation protocol seems to be insufficient to attain effective recovery of knee-extensor-muscle voluntary strength.

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Rob Duffield, Monique King and Melissa Skein

Purpose:

This study investigated the effects of hot conditions on the acute recovery of voluntary and evoked muscle performance and physiological responses following intermittent exercise.

Methods:

Seven youth male and six female team-sport athletes performed two sessions separated by 7 d, involving a 30-min exercise protocol and 60-min passive recovery in either 22°C or 33°C and 40% relative humidity. The exercise protocol involved a 20-s maximal sprint every 5 min, separated by constant-intensity exercise at 100 W on a cycle ergometer. Maximal voluntary contraction (MVC) and a resting evoked twitch (Pf) of the right knee extensors were assessed before and immediately following exercise and again 15, 30, and 60 min post exercise, and capillary blood was obtained at the same time points to measure lactate, pH, and HCO3. During and following exercise, core temperature, heart rate and rating of perceived exertion (RPE) were also measured.

Results:

No differences (P = 0.73 to 0.95) in peak power during repeated sprints were present between conditions. Post exercise MVC was reduced (P < .05) in both conditions and a moderate effect size (d = 0.60) indicated a slower percentage MVC recovered by 60 min in the heat (83 ± 10 vs 74 ± 11% recovered). Both heart rate and core temperature were significantly higher (P < .05) during recovery in the heat. Capillary blood values did not differ between conditions at any time point, whereas sessional RPE was higher 60 min post exercise in the heat.

Conclusions:

The current data suggests that passive recovery in warm temperatures not only delays cardiovascular and thermal recovery, but may also slow the recovery of MVC and RPE.

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Christos K. Argus, Matthew W. Driller, Tammie R. Ebert, David T. Martin and Shona L. Halson

Purpose:

To evaluate the effectiveness of different recovery strategies on repeat cycling performance where a short duration between exercise bouts is required.

Methods:

Eleven highly trained cyclists (mean ± SD; age = 31 ± 6 y, mass = 74.6 ± 10.6 kg, height = 180.5 ± 8.1 cm) completed 4 trials each consisting of three 30-s maximal sprints (S1, S2, S3) on a cycle ergometer, separated by 20-min recovery periods. In a counterbalanced, crossover design, each trial involved subjects performing 1 of 4 recovery strategies: compression garments (COMP), electronic muscle stimulation (EMS), humidification therapy (HUM), and a passive control (CON). The sprint tests implemented a 60-s preload (at an intensity of 4.5 W/kg) before a 30-s maximal sprint. Mean power outputs (W) for the 3 sprints, in combination with perceived recovery and blood lactate concentration, were used to examine the effect of each recovery strategy.

Results:

In CON, S2 and S3 were (mean ± SD) –2.1% ± 3.9% and –3.1% ± 4.2% lower than S1, respectively. Compared with CON, COMP resulted in a higher mean power output from S1 to S2 (mean ± 90%CL: 0.8% ± 1.2%; possibly beneficial) and from S1 to S3 (1.2% ± 1.9%; possibly beneficial), while HUM showed a higher mean power output from S1 to S3 (2.2% ± 2.5%; likely beneficial) relative to CON.

Conclusion:

The authors suggest that both COMP and HUM may be effective strategies to enhance recovery between repeated sprint-cycling bouts separated by ~30 min.

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Rob Duffield, Alistair Murphy, Aaron Kellett and Machar Reid

Purpose:

To investigate the effects of combining cold-water immersion (CWI), full-body compression garments (CG), and sleep-hygiene recommendations on physical, physiological, and perceptual recovery after 2-a-day on-court training and match-play sessions.

Methods:

In a crossover design, 8 highly trained tennis players completed 2 sessions of on-court tennis-drill training and match play, followed by a recovery or control condition. Recovery interventions included a mixture of 15 min CWI, 3 h of wearing full-body CG, and following sleep-hygiene recommendations that night, while the control condition involved postsession stretching and no regulation of sleeping patterns. Technical performance (stroke and error rates), physical performance (accelerometry, countermovement jump [CMJ]), physiological (heart rate, blood lactate), and perceptual (mood, exertion, and soreness) measures were recorded from each on-court session, along with sleep quantity each night.

Results:

While stroke and error rates did not differ in the drill session (P > .05, d < 0.20), large effects were evident for increased time in play and stroke rate in match play after the recovery interventions (P > .05, d > 0.90). Although accelerometry values did not differ between conditions (P > .05, d < 0.20), CMJ tended to be improved before match play with recovery (P > .05, d = 0.90). Furthermore, CWI and CG resulted in faster postsession reductions in heart rate and lactate and reduced perceived soreness (P > .05, d > 1.00). In addition, sleep-hygiene recommendations increased sleep quantity (P > .05, d > 2.00) and maintained lower perceived soreness and fatigue (P < .05, d > 2.00).

Conclusions:

Mixed-method recovery interventions (CWI and CG) used after tennis sessions increased ensuing time in play and lower-body power and reduced perceived soreness. Furthermore, sleep-hygiene recommendations helped reduce perceived soreness.

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Hugh H.K. Fullagar, Rob Duffield, Sabrina Skorski, David White, Jonathan Bloomfield, Sarah Kölling and Tim Meyer

Purpose:

The current study examined the sleep, travel, and recovery responses of elite footballers during and after long-haul international air travel, with a further description of these responses over the ensuing competitive tour (including 2 matches).

Methods:

In an observational design, 15 elite male football players undertook 18 h of predominantly westward international air travel from the United Kingdom to South America (–4-h time-zone shift) for a 10-d tour. Objective sleep parameters, external and internal training loads, subjective player match performance, technical match data, and perceptual jet-lag and recovery measures were collected.

Results:

Significant differences were evident between outbound travel and recovery night 1 (night of arrival; P < .001) for sleep duration. Sleep efficiency was also significantly reduced during outbound travel compared with recovery nights 1 (P = .001) and 2 (P = .004). Furthermore, both match nights (5 and 10), showed significantly less sleep than nonmatch nights 2 to 4 and 7 to 9 (all P < .001). No significant differences were evident between baseline and any time point for all perceptual measures of jet-lag and recovery (P > .05), although large effects were evident for jet-lag on d 2 (2 d after arrival).

Conclusions:

Sleep duration is truncated during long-haul international travel with a 4-h time-zone delay and after night matches in elite footballers. However, this lost sleep appeared to have a limited effect on perceptual recovery, which may be explained by a westbound flight and a relatively small change in time zones, in addition to the significant increase in sleep duration on the night of arrival after the long-haul flight.

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Mark D. Haub, Jeffrey A. Potteiger, Dennis J. Jacobsen, Karen L. Nau, Lawrence A. Magee and Matthew J. Comeau

We investigated the effects of carbohydrate ingestion on glycogen replenishment and subsequent short duration, high intensity exercise performance. During Session 1, aerobic power was determined and each subject (N = 6) was familiarized with the 100-kJ cycling test (lOOKJ-Test). During the treatment sessions, the subjects performed a lOOKJ-Test (Ride-1), then consumed 0.7 g ⋅ kg body mass-1 of maltodextrin (CHO) or placebo (PLC), rested 60 min, and then performed a second lOOKJ-Test (Ride-2). Muscle tissue was collected before (Pre-1) and after Ride-1 (Post-1), and before (Pre-2) and after Ride-2 (Post-2), and analyzed for glycogen concentration. Both treatments yielded a significant increase in glycogen levels following the 60-min recovery, but there was no difference between treatments. Time to complete the lOOKJ-Test increased significantly for PLC, but not for CHO. These data indicate that the decrease in performance during Ride-2 in PLC was not the result of a difference in glycogen concentration.

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Robert Carter III, Samuel N. Cheuvront and Michael N. Sawka

Objectives:

We report our observations on one soldier with abnormal hyperthermia during exercise in the heat compared with prior exercise and following acute local (non-febrile) infection. Also, we report on 994 heat stroke hospitalizations in the U.S. Army. It is known that prior infection is a risk factor for heat illness and some of the 37 heat stroke deaths cited infections (eg, pneumonia, influenza) in the medical records.

Results:

This case report illustrates complete recovery from abnormal hyperthermia, which occurred in a laboratory setting during mild, low intensity exercise. In a field setting, this case may have resulted in serious heat illness. As with most of the heat stroke cases, rapid medical attention (ie, cooling and rehydration) and the age group (19 to 26) that represents majority of the heatstroke cases in U.S. Army are likely factors that contribute successful treatment of heatstroke in the field environment.

Conclusions:

We conclude that acute inflammatory response can augment the hyperthermia of exercise and possibly increase heat illness susceptibility. Furthermore, it is important for health care providers of soldiers and athletes to monitor acute local infections due to the potential thermoregulatory consequences during exercise in the heat.

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Christine E. Dziedzic and Dean G. Higham

Rugby sevens is an abbreviated version of rugby union, played by teams of seven players over 7-min halves. International competitions are usually played in a tournament format. While shorter in duration, the movement demands of rugby sevens per min of match time are greater than rugby union, resulting in an accentuated load on players. This load can be repeated up to six times over a typical 2- or 3-day competition period. The potential cumulative effect of inadequate carbohydrate, protein and/or fluid intake over the course of a tournament is the greatest nutrition-related concern for players. Nutritional strategies before and during competition are suggested to replenish substrate stores, maintain fluid balance and promote recovery between matches. The use of ergogenic aids known to enhance intermittent, high-intensity activity and/or the execution of motor skills may be advantageous to rugby sevens performance and is discussed. This review provides a best-practice model of nutritional support for international rugby sevens competition based on our current understanding of the sport combined with pragmatic guidelines and considerations for the practitioner.

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Robin T. Thorpe, Greg Atkinson, Barry Drust and Warren Gregson

The increase in competition demands in elite team sports over recent years has prompted much attention from researchers and practitioners to the monitoring of adaptation and fatigue in athletes. Monitoring fatigue and gaining an understanding of athlete status may also provide insights and beneficial information pertaining to player availability, injury, and illness risk. Traditional methods used to quantify recovery and fatigue in team sports, such as maximal physical-performance assessments, may not be feasible to detect variations in fatigue status throughout competitive periods. Faster, simpler, and nonexhaustive tests such as athlete self-report measures, autonomic nervous system response via heart-rate-derived indices, and to a lesser extent, jump protocols may serve as promising tools to quantify and establish fatigue status in elite team-sport athletes. The robust rationalization and precise detection of a meaningful fluctuation in these measures are of paramount importance for practitioners working alongside athletes and coaches on a daily basis. There are various methods for arriving at a minimal clinically important difference, but these have been rarely adopted by sport scientists and practitioners. The implementation of appropriate, reliable, and sensitive measures of fatigue can provide important information to key stakeholders in team-sport environments. Future research is required to investigate the sensitivity of these tools to fundamental indicators such as performance, injury, and illness.

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Matthew Finberg, Rebecca Braham, Carmel Goodman, Peter Gregory and Peter Peeling

Purpose:

To assess the efficacy of a 1-off electrostimulation treatment as a recovery modality from acute teamsport exercise, directly comparing the benefits to contrast water therapy.

Methods:

Ten moderately trained male athletes completed a simulated team-game circuit (STGC). At the conclusion of exercise, participants then completed a 30-min recovery modality of either electrostimulation therapy (EST), contrast water therapy (CWT), or a passive resting control condition (CON). Twenty-four hours later, participants were required to complete a modified STGC as a measure of next-day performance. Venous blood samples were collected preexercise and 3 and 24 h postexercise. Blood samples were analyzed for circulating levels of interleukin-6 (IL-6) and C-reactive protein (CRP).

Results:

The EST trial resulted in significantly faster sprint times during the 24-h postrecovery than with CON (P < .05), with no significant differences recorded between EST and CWT or between CWT and CON (P > .05). There were no differences in IL-6 or CRP across all trials. Finally, the perception of recovery was significantly greater in the EST trial than in the CWT and CON (P < .05).

Conclusions:

These results suggest that a 1-off treatment with EST may be beneficial to perceptual recovery, which may enhance next-day performance.