This study (a) compared accelerometer wear time and compliance between distinct wrist-worn accelerometer data collection plans, (b) analyzed participants’ perception of using accelerometers, and (c) identified sociodemographic and behavioral correlates of accelerometer compliance. A sample of high school students (n = 143) wore accelerometers attached to the wrist by a disposable polyvinyl chloride (PVC) wristband or a reusable fabric wristband for 24 hr over 6 days. Those who wore the reusable fabric band, but not their peers, were instructed to remove the device during water-based activities. Participants answered a questionnaire about sociodemographic and behavioral characteristics and reported their experience wearing the accelerometer. We computed non-wear time and checked participants’ compliance with wear-time criteria (i.e., at least three valid weekdays and one valid weekend day) considering two valid day definitions separately (i.e., at least 16 and 23 hours of accelerometer data). Participants who wore a disposable band had greater compliance compared with those who wore a reusable band for both 16-hr (93% vs. 76%, respectively) and 23-hr valid day definitions (91% vs. 50%, respectively). High schoolers with the following characteristics were less likely to comply with wear time criteria if they (a) engaged in labor-intensive activities, (b) perceived that wearing the monitor hindered their daily activities, or (c) felt ashamed while wearing the accelerometer. In conclusion, the data collection plan composed of using disposable wristbands and not removing the monitor resulted in greater 24-hr accelerometer wear time and compliance. However, a negative experience in using the accelerometer may be a barrier to high schoolers’ adherence to rigorous protocols.
Marcus V.V. Lopes, Bruno G.G. da Costa, Luis E.A. Malheiros, Rafael M. Costa, Ana C.C. Souza, Inacio Crochemore-Silva, and Kelly S. Silva
Mário A.M. Simim, Marco Túlio de Mello, Bruno V.C. Silva, Dayane F. Rodrigues, João Paulo P. Rosa, Bruno Pena Couto, and Andressa da Silva
The aim of this review was to identify the main variables for load monitoring in training and competition situations in wheelchair sports. Studies were identified from a systematic search of three databases (PubMed, Web of Science, and SportDiscuss), with search phrases constructed from MeSH terms, alone or in combination, limited to English-language literature, and published up to January 2016. Our main findings were that variables related to external load (distance, speed, and duration) are used to monitor load in competition. In training situations, researchers have used variables related to internal load (heart rate and VO2); in both training and competition situations, researchers used internal load measurements (training impulse and ratings of perceived exertion). We conclude that the main variables for load monitoring in competitive situations were distance, speed, and duration, whereas the variables for training situations were heart rate, VO2, training impulse, and ratings of perceived exertion.
Andressa Silva, Fernanda V. Narciso, Igor Soalheiro, Fernanda Viegas, Luísa S.N. Freitas, Adriano Lima, Bruno A. Leite, Haroldo C. Aleixo, Rob Duffield, and Marco T. de Mello
Purpose: To investigate the relationship between sleep quality and quantity and injuries in elite soccer players and to compare sleep–wake variables and injury characteristics. Methods: The current investigation was a prospective cohort study of 23 elite male soccer players competing for 2 teams over 6 mo in the highest-level Brazilian competition. The players’ sleep behavior was monitored for 10 d in the preseason using self-reporting sleep diaries and wrist activity monitors to determine sleep duration and quality. Furthermore, injuries were recorded by the respective club’s medical teams into a specific database. Details of injuries recorded included the type, location, and severity of each injury. The results were expressed as descriptive statistics, and the significance level was set at 5%. The Mann–Whitney U test was performed to compare the sleep variables between groups. Spearman correlation coefficient and linear-regression analysis were used. Results: The results indicated a moderate negative correlation between sleep efficiency and particular injury characteristics, including absence time, injury severity, and amount of injuries. The linear-regression analysis indicated that 44% of the total variance in the number of injuries can be explained by sleep efficiency, 24% of the total variance in the absence time after injury (days) can be explained by sleep efficiency, and 47% of the total variance in the injury severity can be explained by sleep efficiency. Conclusions: Soccer players who exhibit lower sleep quality or nonrestorative sleep show associations with increased number and severity of musculoskeletal injuries.
Mário A.M. Simim, Gustavo R. da Mota, Moacir Marocolo, Bruno V.C. da Silva, Marco Túlio de Mello, and Paul S. Bradley
We investigated the match demands (distances covered and acute physiological responses) of amputee soccer and its impact on muscular endurance and power. Measures such as heart rate, blood lactate concentration, subjective rating of perceived exertion, and time-motion characteristics were recorded in 16 Brazilian amputee soccer players during matches. Before and after matches, players completed a battery of tests: push-ups, countermovement vertical jump performance, and medicine ball throwing. Small differences were found between the first and second half for the distance covered in total and across various speed categories. Heart rate responses, blood lactate concentrations, and peak speed did not differ between halves, and all neuromuscular performance measures decreased after the match particularly after push-ups, although the rating of perceived exertion increased markedly compared with prematches. Although match physical performances were consistent across halves, the overall demands impaired test performance, especially for upper limb and closed kinetic chain exercise.
Yuri A. Freire, Carlos A. Silva, Geovani A. D. Macêdo, Rodrigo A. V. Browne, Bruno M. de Oliveira, George Felipe C. Martins, Luiz F. Farias-Junior, Luciana C. Brito, and Eduardo C. Costa
We carried out three types of 2-hr experimental sessions with middle-aged and older adults with Type 2 diabetes in order to examine the acute effect of interrupting prolonged sitting with varying periods of standing on postprandial glycemia and blood pressure (BP): (a) prolonged sitting after breakfast; (b) standing for 10 min, 30 min after breakfast; and (c) standing for 20 min, 30 min after breakfast. Glucose and BP were assessed before and after breakfast. A generalized linear model revealed no significant differences for the incremental area under the curve of glucose between standing for 10 min, 30 min after breakfast, versus prolonged sitting after breakfast (β = –4.5 mg/dl/2 hr, 95% CI [–17.3, 8.4]) and standing for 20 min, 30 min after breakfast, versus prolonged sitting after breakfast (β = 0.9 mg/dl/2 hr, 95% CI [–11.9, 13.7]). There was no difference in area under the curve of systolic and diastolic BP among the sessions. Interrupting prolonged sitting time with 10 or 20 min of standing 30 min after breakfast does not attenuate postprandial glycemia or BP in middle-aged and older adults with Type 2 diabetes.