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  • Author: Greg D. Wells x
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Jason D. Vescovi, Olesya Falenchuk and Greg D. Wells

Purpose:

Blood lactate concentration, [BLa], after swimming events might be influenced by demographic features and characteristics of the swim race, whereas active recovery enhances blood lactate removal. Our aims were to (1) examine how sex, age, race distance, and swim stroke influenced [BLa] after competitive swimming events and (2) develop a practical model based on recovery swim distance to optimize blood lactate removal.

Methods:

We retrospectively analyzed postrace [BLa] from 100 swimmers who competed in the finals at the Canadian Swim Championships. [BLa] was also assessed repeatedly during the active recovery. Generalized estimating equations were used to evaluate the relationship between postrace [BLa] with independent variables.

Results:

Postrace [BLa] was highest following 100–200 m events and lowest after 50 and 1500 m races. A sex effect for postrace [BLa] was observed only for freestyle events. There was a negligible effect of age on postrace [BLa]. A model was developed to estimate an expected change in [BLa] during active recovery (male = 0; female = 1): [BLa] change after active recovery = –3.374 + (1.162 × sex) + (0.789 × postrace [BLa]) + (0.003 × active recovery distance).

Conclusions:

These findings indicate that swimmers competing at an elite standard display similar postrace [BLa] and that there is little effect of age on postrace [BLa] in competitive swimmers aged 14 to 29 y.

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Jairus J. Quesnele, Michelle A. Laframboise, Jessica J. Wong, Peter Kim and Greg D. Wells

Purpose:

To critically review the methodological quality and synthesize information from systematic reviews and high quality studies on the effects of beta alanine (BA) on exercise and athletic performance.

Methods:

A search strategy was developed in accordance with the standards for the reporting of scientific literature via systematic reviews. Five databases were thoroughly searched from inception to November 2012. Inclusion criteria were English language, human studies, used BA to increase exercise or athletic performance, systematic reviews or randomized controlled trials and were published in a peer-reviewed journal. Included studies were systematically graded for their methodological quality by rotating pairs of reviewers and the results were qualitatively synthesized.

Results:

One systematic review and 19 randomized trials were included in this review. There is one systematic review with several methodological weaknesses that limit the confidence in its results. There are moderate to high quality studies that appear to support that BA may increase power output and working capacity, decrease the feeling of fatigue and exhaustion, and have of positive effect on body composition and carnosine content. The reporting of side effects from BA supplementation in the athletic population was generally under-reported.

Conclusions:

There appears to be some evidence from this review that supplementation with BA may increase athletic performance. However, there is insufficient evidence examining the safety of BA supplementation and its side effects. It is therefore recommended to err on the side of caution in using BA as an ergogenic aid until there is sufficient evidence confirming its safety.

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Sarah L. West, Adam Gassas, Tal Schechter, R. Maarten Egeler, Paul C. Nathan and Greg D. Wells

Hematopoietic stem-cell transplant (SCT) is increasingly used to treat children with cancer, and survival following SCT is improving. One predominant consequence of childhood cancer therapy is increased physical morbidity, which is worse in pediatric SCT recipients compared with children treated with chemotherapy or radiation alone. There are many factors that contribute to exercise intolerance and reduced physical function during the pretransplant, peritransplant, and posttransplant phases. These include side effects from chemotherapy or radiation, excessive immobility due to bed rest, infections, the negative effects of immunosuppressants, and graft vs host disease, all of which can impair cardiorespiratory fitness, muscle strength, and muscle function. Few studies have investigated the effects of exercise in childhood SCT recipients. In a small number of published studies, exercise interventions have been demonstrated to improve cardiorespiratory fitness, preserve or increase muscle mass, and improve muscle strength in children following SCT. The use of exercise as medicine may be a noninvasive and nonpharmaceutical treatment to target physical complications post-SCT. Researchers and health-care professionals should work together to develop exercise prescription guidelines for this unique and important population.