Sports, Volume 3, Issue 4 (December 2015) – 9 articles , Pages 269-382

This study examined patterns of responses for physiological and perceptual variables during cycle ergometry at a constant rate of perceived exertion (RPE) within the moderate and heavy exercise intensity domains. Nineteen (mean age 21.3 ± 0.5 years; 43.4 ± 2.0 mL·kg⁻¹·min⁻¹ V ˙ O 2 Peak ) moderately trained cyclists performed an incremental test to exhaustion and two 60 min constant RPE rides at the RPE corresponding to the gas exchange threshold (RPE_GET) and 15% above the GET (RPE_GET+15%). Oxygen consumption ( V ˙ O₂), respiratory exchange ratio (RER), heart rate (HR), minute ventilation ( V ˙ E ), breathing frequency ( ℱ b ), and power output (PO) were monitored throughout the rides. Polynomial regression analyses showed V ˙ O₂, RER, HR, and V ˙ E (correlation = −0.85 to −0.98) tracked the decreases in PO required to maintain a constant RPE. Only ℱ b tracked RPE during the moderate and heavy intensity rides. Repeated measures ANOVAs indicated that V ˙ O₂ during the 60 min rides at RPE_GET was not different (p > 0.05) from V ˙ O₂ at GET from the incremental test to exhaustion. Thus, monitoring intensity using an RPE associated with the GET is sustainable for up to 60 min of cycling exercise and a common mechanism may mediate ℱ b and the perception of effort during moderate and heavy intensity cycle ergometry. Full article

Recent studies in adults have shown that the critical intensity during running and cycling estimated from three prediction trials interspersed by 30 min is valid and reliable. To establish the reliability of the single-visit field test to determine critical speed (CS) and the distance above critical speed (D′) in adolescents, 29 trained and 14 untrained participants (mean ± SD age: 17.5 ± 0.5 years) performed three tests on a 400-m outdoor track separated by 48 h. Each test consisted of three distances selected to result in finishing times between 2 and 15 min that must be completed as fast as possible. CS and D′ were modeled using the linear 1/time model (Speed = D′(1/t) + CS). While the coefficient of variation (CV) of CS was between 2.4% and 4.3%, the CV of D′ was 9.3% to 13.6%. Also the intraclass correlation coefficient ranged from 0.919 to 0.983 for CS and from 0.325 to 0.828 for D′. The results show that the single-visit field test provides reliable estimates of CS but not D′ in trained and untrained adolescents. Full article

Puberty is characterized by a large number of physiological modifications that translate into increased neuromuscular fatigue during high-intensity exercise in adolescents compared to prepubertal children. This greater neuromuscular fatigue in adolescents could be attributed to peripheral (i.e., muscular) and central (i.e., nervous) factors that change through puberty. Among the peripheral changes are muscle mass, fiber type composition, energy metabolism and musculo-tendinous stiffness. Among the central modifications are the voluntary activation level, the antagonist co-activation and a differential interplay between central and peripheral fatigue. The objective of this review article will be to underline the importance of these factors on the development of neuromuscular fatigue during high-intensity exercise throughout puberty and to highlight that the adolescents could be physiologically less protected against fatiguing high-intensity exercise than their prepubertal counterparts. Full article

Aim: An effective catch in sculling is a critical determinant of boat velocity. This study used rowers’ performance-based judgments to compare three measures of catch slip efficiency. Two questions were addressed: (1) would rower-judged Yes strokes be faster than No strokes? and (2) which method of quantifying catch slip best reflected these judgements? Methods: Eight single scullers performed two 10-min blocks of sub maximal on-water rowing at 20 strokes per minute. Every 30 s, rowers reported either Yes or No about the quality of their stroke at the catch. Results: It was found that Yes strokes identified by rowers had, on average, a moderate effect advantage over No strokes with a standardised effect size of 0.43. In addition, a quicker time to positive acceleration best reflected the change in performance; where the standardised mean difference score of 0.57 for time to positive acceleration was larger than the scores of 0.47 for time to PowerLine force, and 0.35 for time to 30% peak pin force catch slip measures. For all eight rowers, Yes strokes corresponded to time to positive acceleration occurring earlier than No strokes. Conclusion: Rower judgements about successful strokes was linked to achieving a quicker time to positive acceleration, and may be of the most value in achieving a higher average boat velocity. Full article

Athletes have preferences for the way in which they internalize and process information, whether that is visual, aural, by-doing (kinesthetic), reading or a mixture of preferences. Health professionals that interact with athletes rarely consider the individual learning style prior to any communication or education, despite mounting evidence for the benefits of learning-style tailored education. The aim of this study was to characterize athletes with regards to their preferred learning style. Athletes (n = 93) from 24 sports and various sport achievement levels completed a questionnaire, including the visual (V), auditory (A), reading/writing (R), kinesthetic (K)/(VARK) Questionnaire for Athletes. Questionnaire outcomes were analysed by X² analysis on SPSS. The main findings were: (1) very few athletes have a visual learning-style preference; (2) there was a significant relationship between gender and VARK preference (X² = 13.84, p = 0.003); (3) and between athletic status and VARK preference (X² = 9.2, p = 0.025); (4) there was a trivial association between individual/ team sport athletes and assessed VARK preference (X² = 3.95, p = 0.265). Our findings show significant variation in learning-style preference between males and females, and those of different athletic status. Health professionals should be aware of the inadequacy of visual information presentation when working with athletes. Furthermore, health professionals working with elite and female athletes should be comfortable using a mixture of learning styles (multi-modal). Full article

Exercise performance is partially limited by the functionality of the respiratory musculature. Training these muscles improves steady-state exercise performance. However, less is known about the efficacy of executing a respiratory muscle warm-up (RWU) immediately prior to high-intensity exercise. Our study purpose was to use a practitioner-friendly airflow restriction device to investigate the effects of a high, medium, or low intensity RWU on short, high-intensity exercise and pulmonary, cardiovascular, and metabolic function. Eleven recreationally active, males (24.9 ± 4.2 y, 178.8 ± 9.0 cm, 78.5 ± 10.4 kg, 13.4% ± 4.2% body fat) cycled at 85% peak power to exhaustion (TTE) following four different RWU conditions (separate days, in random order): (1) high; (2) medium; (3) low airflow inspiration restriction, or no RWU. When analyzed as a group, TTE did not improve following any RWU (4.73 ± 0.33 min). However, 10 of the 11 participants improved ≥25 s in one of the three RWU conditions (average = 47.6 ± 13.2 s), which was significantly better than (p < 0.05) the control trial (CON). Neither blood lactate nor perceived difficulty was altered by condition. In general, respiratory exchange ratios were significantly lower during the early stages of TTE in all RWU conditions. Our findings suggest RWU efficacy is predicated on identifying optimal inspiration intensity, which clearly differs between individuals. Full article

American adults and an increasing number of children, are not meeting the recommended amounts of daily physical activity. Research has documented the effects of low activity on health and increasingly new research has shown that low activity levels now impact academic achievement. Physical education (PE) can play an important role if the children participating are obtaining enough physical activity while in class and the PE program has not been targeted with cutbacks. The purpose of this study was to identify the amount and intensity of activity in PE classes. The results indicate that on average students at all levels are not meeting the activity requirements. In addition, PE teachers’ perceptions of physical activity in their own class does not match actual activity levels. PE teachers must do a better job of increasing activity levels in their classrooms. Mounting research indicates students perform better academically if they are physically active. PE is the only subject where teachers can organize activities that meet both activity and intensity requirements. Full article

There is growing evidence to support change in the rehabilitation strategy of patellofemoral pain syndrome (PFPS) from traditional quadriceps strengthening exercises to inclusion of hip musculature strengthening in individuals with PFPS. Several studies have evaluated effects of quadriceps and hip musculature strengthening on PFPS with varying outcomes on pain and function. This systematic review and meta-analysis aims to synthesize outcomes of pain and function post-intervention and at follow-up to determine whether outcomes vary depending on the exercise strategy in both the short and long term. Electronic databases including MEDLINE, EMBASE, CINAHL, Web of Science, PubMed, Pedro database, Proquest, Science direct, and EBscoHost databases were searched for randomized control trials published between 1st of January 2005 and 31st of June 2015, comparing the outcomes of pain and function following quadriceps strengthening and hip musculature strengthening exercises in patients with PFPS. Two independent reviewers assessed each paper for inclusion and quality. Means and SDs were extracted from each included study to allow effect size calculations and comparison of results. Six randomized control trials met the inclusion criteria. Limited to moderate evidence indicates that hip abductor strengthening was associated with significantly lower pain post-intervention (SMD −0.88, −1.28 to −0.47 95% CI), and at 12 months (SMD −3.10, −3.71 to −2.50 95% CI) with large effect sizes (greater than 0.80) compared to quadriceps strengthening. Our findings suggest that incorporating hip musculature strengthening in management of PFPS tailored to individual ability will improve short-term and long-term outcomes of rehabilitation. Further research evaluating the effects of quadriceps and hip abductors strengthening focusing on reduction in anterior knee pain and improvement in function in management of PFPS is needed. Full article

This study compared electromyographic (EMG) amplitude, the number of repetitions completed, and exercise volume during three sets to failure of high- (80% 1RM) versus low-load (30% 1RM) forearm flexion resistance exercise on a subject-by-subject basis. Fifteen men were familiarized, completed forearm flexion 1RM testing. Forty-eight to 72 h later, the subjects completed three sets to failure of dumbbell forearm flexion resistance exercise with 80% (n = 8) or 30% (n = 7) 1RM. EMG amplitude was calculated for every repetition, and the number of repetitions performed and exercise volume were recorded. During sets 1, 2, and 3, one of eight subjects in the 80% 1RM group demonstrated a significant linear relationship for EMG amplitude versus repetition. For the 30% 1RM group, seven, five, and four of seven subjects demonstrated significant linear relationships during sets 1, 2, and 3, respectively. The mean EMG amplitude responses show that the fatigue-induced increases in EMG amplitude for the 30% 1RM group and no change in EMG amplitude for the 80% 1RM group resulted in similar levels of muscle activation in both groups. The numbers of repetitions completed were comparatively greater, while exercise volumes were similar in the 30% versus 80% 1RM group. Our results, in conjunction with those of previous studies in the leg extensors, suggest that there may be muscle specific differences in the responses to high- versus low-load exercise. Full article