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Peter M. Tiidus, Joel Cort, Sarah J. Woodruff and Pamela Bryden

Objectives:

To evaluate ultrasound’s effectiveness after eccentric-exercise-induced muscle damage.

Participants:

22 subjects.

Intervention:

Random assignment to ultrasound (UT) or placebo (PT). Ultrasound was applied immediately and 24, 48, and 72 h after 50 maximum eccentric contractions of the biceps.

Outcome Measures:

Concentric and eccentric peak torques, resting elbow angle, and subjective muscle soreness were measured before and 24, 48, 72, and 96 h afterward.

Results:

No significant differences between UT and PT for biceps concentric or eccentric peak torque were noted. Both groups exhibited significant (P < .01) depression in eccentric and concentric peak torques with a slow return toward preexercise values over 96 h. Resting elbow angles for both groups were significantly lower than preexercise values up to 96 h (P < .01). Muscle soreness increased significantly (P < .05) at 24 and 48 h and returned to preexercise levels by 96 h.

Conclusions:

Daily ultrasound did not influence recovery after eccentric-exercise-induced muscle damage.

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Michael F. Bergeron

In contrast to muscle cramps that are brought on by muscle overload or fatigue, exertional heat cramps seem to be prompted by extensive sweating and a significant sweat-induced whole-body sodium deficit. As a result of a consequent contracted interstitial compartment, axon terminals of selected motor neurons can become hyper-excitable and spontaneously discharge. Barely detectable muscle fasciculations or “twitches” in the affected muscles can rapidly progress to debilitating muscle cramps in just 20 to 30 minutes. To aid recovery, salt (NaCl) and water lost from sweating should be sufficiently replaced so as to restore the extracellular volume and interstitial fluid spaces. Sweat sodium, chloride, and fluid losses incurred during training and competition need to be closely matched by daily salt and fluid intake, in order to prevent an excessive sodium deficit, maintain sufficient fluid balance, and avoid exertional heat cramps.

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Brandon Rohrer, Susan Fasoli, Hermano Igo Krebs, Bruce Volpe, Walter R Frontera, Joel Stein and Neville Hogan

Submovements are hypothesized building blocks of human movement, discrete ballistic movements of which more complex movements are composed. Using a novel algorithm, submovements were extracted from the point-to-point movements of 41 persons recovering from stroke. Analysis of the extracted submovements showed that, over the course of therapy, patients' submovements tended to increase in peak speed and duration. The number of submovements employed to produce a given movement decreased. The time between the peaks of adjacent submovements decreased for inpatients (those less than 1 month post-stroke), but not for outpatients (those greater than 12 months post-stroke) as a group. Submovements became more overlapped for all patients, but more markedly for inpatients. The strength and consistency with which it quantified patients' recovery indicates that analysis of submovement overlap might be a useful tool for measuring learning or other changes in motor behavior in future human movement studies.

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George P. Elias, Matthew C. Varley, Victoria L. Wyckelsma, Michael J. McKenna, Clare L. Minahan and Robert J. Aughey

Purpose:

The authors investigated the efficacy of a single exposure to 14 min of cold-water immersion (COLD) and contrast water therapy (CWT) on posttraining recovery in Australian football (AF).

Method:

Fourteen AF players participated in 3 wk of standardized training. After week 1 training, all players completed a passive recovery (PAS). During week 2, COLD or CWT was randomly assigned. Players undertook the opposing intervention in week 3. Repeat-sprint ability (6 × 20 m), countermovement and squat jumps, perceived muscle soreness, and fatigue were measured pretraining and over 48 h posttraining.

Results:

Immediately posttraining, groups exhibited similar performance and psychometric declines. At 24 h, repeat-sprint time had deteriorated by 4.1% for PAS and 1.0% for CWT but was fully restored by COLD (0.0%). At 24 and 48 h, both COLD and CWT attenuated changes in mean muscle soreness, with COLD (0.6 ± 0.6 and 0.0 ± 0.4) more effective than CWT (1.9 ± 0.7 and 1.0 ± 0.7) and PAS having minimal effect (5.5 ± 0.6 and 4.0 ± 0.5). Similarly, after 24 and 48 h, COLD and CWT both effectively reduced changes in perceived fatigue, with COLD (0.6 ± 0.6 and 0.0 ± 0.6) being more successful than CWT (0.8 ± 0.6 and 0.7 ± 0.6) and PAS having the smallest effect (2.2 ± 0.8 and 2.4 ± 0.6).

Conclusions:

AF training can result in prolonged physical and psychometric deficits persisting for up to 48 h. For restoring physical-performance and psychometric measures, COLD was more effective than CWT, with PAS being the least effective. Based on these results the authors recommend that 14 min of COLD be used after AF training.

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Sebastian Altfeld, Paul Schaffran, Jens Kleinert and Michael Kellmann

(Vulnerability-Stress Model; Liebermann, 1986 ). According to this model, individuals with a higher vulnerability show higher rates of psychological illnesses compared to those with a lower vulnerability when exposed to identical living conditions ( Miller, Chen, & Zhou, 2007 ). Negative Cycle: Why Is Recovery

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Justin P. Guilkey, Brandon Dykstra, Jennifer Erichsen and Anthony D. Mahon

Purpose:

This study examined heart rate recovery (HRR) and heart rate variability (HRV) following maximal exercise in lean (<85th percentile age- and sex-BMI percentile; n = 11 (♂=5; ♀=6); 10.1 ± 0.7 years) and overweight (≥85th age- and sex-BMI percentile; n = 11 (♂=5; ♀=6); 10.5 ± 1.2 years) children.

Method:

Participants completed a 10-min rest, followed by a graded exercise test to maximal effort. HRV, in the time and frequency domains, was assessed during rest and recovery. Also during recovery, one-minute HRR and the time constant of a monoexponential line of best fit (HRRt) were determined.

Results:

There were no significant differences in one-minute HRR and HRRt between the lean (56 ± 7 beats∙min-1 and 160.4 ± 80.1 s, respectively) and overweight (51 ± 16 beats∙min-1 and 141.1 ± 58.1 s, respectively) groups. There also were no significant interactions between groups from rest to recovery for any HRV variables. Root mean square of successive differences (RMSSD) and high frequency power (HF) during recovery was 2.05 ± 0.49 ms and 3.30 ± 1.02 ms2 in the lean children, respectively. In the overweight children, RMSSD and HF were 1.88 ± 0.65 ms and 2.94 ± 1.27 ms2, respectively.

Conclusion:

HRR and HRV findings suggest there are no differences in autonomic function during recovery from maximal exercise in lean and obese 8- to 12-year old children.

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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.

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Takeshi Kokubo, Yuta Komano, Ryohei Tsuji, Daisuke Fujiwara, Toshio Fujii and Osamu Kanauchi

, including antigen presentation and antiviral infection ( Cervantes-Barragan et al., 2012 ; Siegal et al., 1999 ); however, its role during exercise and presentation of related symptoms is unclear. This preclinical study was designed to study the mechanism of attenuation of fatigue and recovery by LC

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Laurent Mourot, Nicolas Fabre, Erik Andersson, Sarah Willis, Martin Buchheit and Hans-Christer Holmberg

Postexercise heart-rate (HR) recovery (HRR) indices have been associated with running and cycling endurance-exercise performance. The current study was designed (1) to test whether such a relationship also exists in the case of cross-country skiing (XCS) and (2) to determine whether the magnitude of any such relationship is related to the intensity of exercise before obtaining HRR indices. Ten elite male cross-country skiers (mean ± SD; 28.2 ± 5.4 y, 181 ± 8 cm, 77.9 ± 9.4 kg, 69.5 ± 4.3 mL · min−1 · kg−1 maximal oxygen uptake [VO2max]) performed 2 sessions of roller-skiing on a treadmill: a 2 × 3-km time trial and the same 6-km at an imposed submaximal speed followed by a final 800-m time trial. VO2 and HR were monitored continuously, while HRR and blood lactate (BLa) were assessed during 2 min immediately after each 6-km and the 800-m time trial. The 6-km time-trial time was largely negatively correlated with VO2max and BLa. On the contrary, there was no clear correlation between the 800-m time-trial time and VO2, HR, or BLa. In addition, in no case was any clear correlation between any of the HRR indices and performance time or VO2max observed. These findings confirm that XCS performance is largely correlated with VO2max and the ability to tolerate high levels of BLa; however, postexercise HRR showed no clear association with performance. The homogeneity of the group of athletes involved and the contribution of the arms and upper body to the exercise preceding determination of HRR may explain this absence of a relationship.

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Sarah Kölling, Rob Duffield, Daniel Erlacher, Ranel Venter and Shona L. Halson

Sleep is increasingly gaining attention among sport scientists and practitioners as an important element to optimize sport performance and recovery. In fact, the critical importance of sleep’s restorative effects in daily life makes it an integral part of the recovery processes for athletes. 1 For