Beer is used to socialize postexercise, celebrate sport victory, and commiserate postdefeat. Rich in polyphenols, beer has antioxidant effects when consumed in moderation, but its alcohol content may confer some negative effects. Despite beer’s popularity, no review has explored its effects on exercise performance, recovery, and adaptation. Thus, a systematic literature search of three databases (PubMed, SPORTDiscus, and Web of Science) was conducted by two reviewers. The search resulted in 16 studies that were appraised and reviewed. The mean PEDro score was 5.1. When individuals are looking to rehydrate postexercise, a low-alcohol beer (<4%) may be more effective. If choosing a beer higher in alcoholic content (>4%), it is advised to pair this with a nonalcoholic option to limit diuresis, particularly when relatively large volumes of fluid (>700 ml) are consumed. Adding Na+ to alcoholic beer may improve rehydration by decreasing fluid losses, but palatability may decrease. These conclusions are largely based on studies that standardized beverage volume, and the results may not apply equally to situations where people ingest fluids and food ad libitum. Ingesting nonalcoholic, polyphenol-rich beer could be an effective strategy for preventing respiratory infections during heavy training. If consumed in moderation, body composition and strength qualities seem largely unaffected by beer. Mixed results that limit sweeping conclusions are owed to variations in study design (i.e., hydration and exercise protocols). Future research should incorporate exercise protocols with higher ecological validity, recruit more women, prioritize chronic study designs, and use ad libitum fluid replacement protocols for more robust conclusions.
Jaison L. Wynne and Patrick B. Wilson
Margot A. Rogers, Michael K. Drew, Renee Appaneal, Greg Lovell, Bronwen Lundy, David Hughes, Nicole Vlahovich, Gordon Waddington, and Louise M. Burke
The Low Energy Availability in Females Questionnaire (LEAF-Q) was validated to identify risk of the female athlete triad (triad) in female endurance athletes. This study explored the ability of the LEAF-Q to detect conditions related to low energy availability (LEA) in a mixed sport cohort of female athletes. Data included the LEAF-Q, SCOFF Questionnaire for disordered eating, dual-energy X-ray absorptiometry-derived body composition and bone mineral density, Mini International Neuropsychiatric Interview, blood pressure, and blood metabolic and reproductive hormones. Participants were grouped according to LEAF-Q score (≥8 or <8), and a comparison of means was undertaken. Sensitivity, specificity, and predictive values of the overall score and subscale scores were calculated in relation to the triad and biomarkers relevant to LEA. Fisher’s exact test explored differences in prevalence of these conditions between groups. Seventy-five athletes (18–32 years) participated. Mean LEAF-Q score was 8.0 ± 4.2 (55% scored ≥8). Injury and menstrual function subscale scores identified low bone mineral density (100% sensitivity, 95% confidence interval [15.8%, 100%]) and menstrual dysfunction (80.0% sensitivity, 95% confidence interval [28.4%, 99.5%]), respectively. The gastrointestinal subscale did not detect surrogate markers of LEA. LEAF-Q score cannot be used to classify athletes as “high risk” of conditions related to LEA, nor can it be used as a surrogate diagnostic tool for LEA given the low specificity identified. Our study supports its use as a screening tool to rule out risk of LEA-related conditions or to create selective low-risk groups that do not need management as there were generally high negative predictive values (range 76.5–100%) for conditions related to LEA.
Allison H. Gruber, Shuqi Zhang, Jiahao Pan, and Li Li
The running footwear literature reports a conceptual disconnect between shoe cushioning and external impact loading: footwear or surfaces with greater cushioning tend to result in greater impact force characteristics during running. Increased impact loading with maximalist footwear may reflect an altered lower-extremity gait strategy to adjust for running in compliant footwear. The authors hypothesized that ankle and knee joint stiffness would change to maintain the effective vertical stiffness, as cushioning changed with minimalist, traditional, and maximalist footwear. Eleven participants ran on an instrumental treadmill (3.5 m·s−1) for a 5-minute familiarization in each footwear, plus an additional 110 seconds before data collection. Vertical, leg, ankle, and knee joint stiffness and vertical impact force characteristics were calculated. Mixed model with repeated measures tested differences between footwear conditions. Compared with traditional and maximalist, the minimalist shoes were associated with greater average instantaneous and average vertical loading rates (P < .050), greater vertical stiffness (P ≤ .010), and less change in leg length between initial contact and peak resultant ground reaction force (P < .050). No other differences in stiffness or impact variables were observed. The shoe cushioning paradox did not hold in this study due to a similar musculoskeletal strategy for running in traditional and maximalist footwear and running with a more rigid limb in minimalist footwear.
Bent R. Rønnestad, Joar Hansen, Thomas C. Bonne, and Carsten Lundby
Purpose: The present case report aimed to investigate the effects of exercise training in temperate ambient conditions while wearing a heat suit on hemoglobin mass (Hbmass). Methods: As part of their training regimens, 5 national-team members of endurance sports (3 males) performed ∼5 weekly heat suit exercise training sessions each lasting 50 minutes for a duration of ∼8 weeks. Two other male athletes acted as controls. After the initial 8-week period, 3 of the athletes continued for 2 to 4 months with ∼3 weekly heat sessions in an attempt to maintain acquired adaptations at a lower cost. Hbmass was assessed in duplicate before and after intervention and maintenance period based on automated carbon monoxide rebreathing. Results: Heat suit exercise training increased rectal temperature to a median value of 38.7°C (range 38.6°C–39.0°C), and during the initial ∼8 weeks of heat suit training, there was a median increase of 5% (range 1.4%–12.9%) in Hbmass, while the changes in the 2 control athletes were a decrease of 1.7% and an increase of 3.2%, respectively. Furthermore, during the maintenance period, the 3 athletes who continued with a reduced number of heat suit sessions experienced a change of 0.7%, 2.8%, and −1.1%, indicating that it is possible to maintain initial increases in Hbmass despite reducing the weekly number of heat suit sessions. Conclusions: The present case report illustrates that heat suit exercise training acutely raises rectal temperature and that following 8 weeks of such training Hbmass may increase in elite endurance athletes.
Ekin Ilke Sen, Sibel Eyigor, Merve Dikici Yagli, Zeynep Alev Ozcete, Tugba Aydin, Fatma Nur Kesiktas, Filiz Yildiz Aydin, Meltem Vural, Nilay Sahin, and Ayse Karan
In the prospective, randomized, controlled multicenter study, 100 patients who were clinically diagnosed with sarcopenia were assigned to either a home-based exercise group or a control group. The home-based training program included exercises with gradually increasing intensity comprising posture, stretching and upper- and lower-extremity muscle-strengthening exercises, balance and coordination exercises, and gait training. Before and 3 months after the exercise program, all the patients were evaluated. The 6-min walking test and Berg Balance Scale scores increased significantly after 3 months in the home-based exercise group compared with the controls. There was also a significant decrease in timed up and go test scores and a significant improvement in quality of life in the exercise group compared with the control group. Our findings indicated that a home-based exercise program can have a positive effect on physical function, balance, and quality of life in patients with sarcopenia.
Patrick D. Fischer, Keith A. Hutchison, James N. Becker, and Scott M. Monfort
Cognitive function plays a role in understanding noncontact anterior cruciate ligament injuries, but the research into how cognitive function influences sport-specific movements is underdeveloped. The purpose of this study was to determine how various cognitive tasks influenced dual-task jump-landing performance along with how individuals’ baseline cognitive ability mediated these relationships. Forty female recreational soccer and basketball players completed baseline cognitive function assessments and dual-task jump landings. The baseline cognitive assessments quantified individual processing speed, multitasking, attentional control, and primary memory ability. Dual-task conditions for the jump landing included unanticipated and anticipated jump performance, with and without concurrent working memory and captured visual attention tasks. Knee kinematics and kinetics were acquired through motion capture and ground reaction force data. Jumping conditions that directed visual attention away from the landing, whether anticipated or unanticipated, were associated with decreased peak knee flexion angle (P < .001). No interactions between cognitive function measures and jump-landing conditions were observed for any of the biomechanical variables, suggesting that injury-relevant cognitive-motor relationships may be specific to secondary task demands and movement requirements. This work provides insight into group- and subject-specific effects of established anticipatory and novel working memory dual-task paradigms on the neuromuscular control of a sport-specific movement.
Karini Borges dos Santos, Paulo Cesar Barauce Bento, Carl Payton, and André Luiz Felix Rodacki
This study described the kinematic variables of disabled swimmers’ performance and correlated them with their functional classification. Twenty-one impaired swimmers (S5–S10) performed 50-m maximum front-crawl swimming while being recorded by four underwater cameras. Swimming velocity, stroke rate, stroke length, intracycle velocity variation, stroke dimensions, hand velocity, and coordination index were analyzed. Kendall rank was used to correlate stroke parameters and functional classification with p < .05. Swimming velocity, stroke length, and submerged phase were positively correlated with the para swimmers functional classification (.61, .50, and .41; p < .05, respectively), while stroke rate, velocity hand for each phase, coordination index, and intracyclic velocity variation were not (τ between −.11 and .45; p > .05). Thus, some objective kinematic variables of the impaired swimmers help to support current classification. Improving hand velocity seems to be a crucial point to be improved among disabled swimmers.
Neil Chapman, John William Whitting, Suzanne Broadbent, Zachary Crowley-McHattan, and Rudi Meir
Hamstring strain injuries are common in sport. Supramaximal eccentric or high-intensity isometric contractions are favored in hamstring strain injury prevention. The effect of combining these contraction modes in such prevention programs as a poststretch isometric contraction is unknown. Poststretch isometric contractions incorporate an active stretch and result in greater final isometric force than isometric contractions at comparable joint angles. This study compared torque and muscle activation levels between maximal voluntary isometric contraction and maximal poststretch isometric contractions of the knee flexors. Participants (n = 9) completed baseline maximal voluntary isometric contraction at 150° knee flexion and maximal poststretch isometric contractions at 120° knee flexion actively stretching at 60°/s to 150° knee flexion for final isometric contraction. Torque of the knee flexors and surface electromyography root mean square (sEMGRMS) of biceps femoris long head were simultaneously recorded and compared between baseline and poststretch isometric at 150° knee flexion. Torque was 14% greater in the poststretch isometric condition compared with baseline maximal voluntary isometric contraction (42.45 [20.75] N·m, 14% [22.18%], P < .001) without increase in sEMGRMS of biceps femoris long head (−.03 mV, ±.06, P = .130, d = .93). Poststretch isometric contractions resulted in supramaximal levels of poststretch isometric torque without increased activation of biceps femoris long head.
Toby Staff, Fernand Gobet, and Andrew Parton
The aim of this study was to compare two methodologies employed by the British Cycling talent identification program. Specifically, the authors investigated cyclists selected to represent GB cycling team at the London 2012 Olympics using (a) a traditional talent identification methodology (British Cycling Olympic Development Program), where selection is based upon race results and (b) a detection talent identification methodology (U.K. Sport Talent Team Program), which is a multi-Olympic event initiative that identifies athletic potential from physical and skill-based tests. To facilitate this comparison, the authors calculated the speed with which expertise was acquired. A Mann–Whitney U test (U = 16.0, p = .031) indicated that the speed of acquiring expertise was quicker in detection talent identification (Mdn = 5.4) than traditional talent identification (Mdn = 7.2). Practice started later with detection talent identification than with traditional talent identification (14.12 years vs. 11.23 years, respectively), which affected the period to excellence. Thus, detection talent identification resulted in an absence of early specialization, which suggests a critical period for attaining cycling expertise. The authors hypothesize a genetic basis of talent and propose that critical periods are important in detection talent identification programs.