Introduction: Benefits of regular physical exercise were demonstrated as preventive and coadjuvant nonpharmacological anticancer therapy. However, the role of exercise in modulating prostate cancer behavior has yet to be established. Methods: Prostate tumors were induced in C57BL/6 male mice (n = 28) by subcutaneous inoculation of a suspension of murine androgen-independent RM1 cells (1.5 × 105 cells/500 μL phosphate-buffered saline) in the dorsal region. Mice were randomly allocated into 2 study groups: sedentary tumor-induced (n = 14) and exercised tumor-induced (n = 14). Exercise consisted of voluntary running in wheeled cages. Mice (n = 7 per group) were sacrificed either 14 or 28 days after cell inoculation to evaluate tumor weight and percentage of area occupied by immunohistochemistry stained cells for Ki-67 and TdT-mediated dUTP-biotin nick end labeling, used as surrogate markers of cell proliferation and apoptosis, respectively. Results: Compared with sedentary tumor-induced mice, the tumors developed by exercised tumor-induced mice were significantly smaller at 14 days (0.17 [0.12] g vs 0.48 [0.24] g, P < .05) and at 28 days (0.92 [0.73] g vs 2.09 [1.31] g, P < .05), with smaller Ki-67 and greater TdT-mediated dUTP-biotin nick end-labeling stained areas (P < .05). Conclusion: These results suggest that regular voluntary running inhibits prostate cancer cell growth by reducing cell proliferation and enhancing apoptosis.
Mário Esteves, Carina Silva, Sofia S. Pereira, Tiago Morais, Ângela Moreira, Madalena M. Costa, Mariana P. Monteiro, and José A. Duarte
Colin B. Shore, Gill Hubbard, Trish Gorely, Angus M. Hunter, and Stuart D.R. Galloway
Background: Exercise referral schemes (ERS) aim to tackle noncommunicable disease via increasing levels of physical activity. Health benefits are reliant on uptake and attending ERS sessions. Hence, it is important to understand which characteristics may influence these parameters to target interventions to improve uptake and attendance to those who need it most. Method: Secondary analysis of one ERS database was conducted to (1) profile participants’ nonuptake of exercise referral; (2) describe any differences between nonattenders and attenders; and (3) report session count of attenders, exploring any relationship between attender demographics and session count. Results: The study showed that (1) sociodemographic profile of nonattenders was very similar to that of those who attended; (2) there was a high, early withdrawal rate of attenders wherein 68% exited the scheme at 5 exercise sessions or less; and (3) session count did not appear to differ by demographic characteristics. Conclusions: Nonattendance and session count did not appear to differ by demographic characteristics. Attendance at ERS was low. Nonuptake and reduced attendance may limit any associated health benefits that may be achieved from ERS. Therefore, it is important to identify additional factors that may influence participants’ choice to uptake and attend ERS.
Christianne F. Coelho-Ravagnani, Jeeser A. Almeida, Xuemei Sui, Fabricio C.P. Ravagnani, Russell R. Pate, and Steven N. Blair
Background: The effects of compliance with the US Physical Activity (PA) Guidelines and changes in compliance over time on cardiovascular disease (CVD) mortality are unknown. Methods: Male participants in the Aerobics Center Longitudinal Study (n = 15,411; 18–100 y) reported leisure-time PA between 1970 and 2002. The frequency of and time spent in PA were converted into metabolic equivalent minutes per week. The participants were classified into remained inactive, became active, became inactive, or remained active groups according to their achievement of the PA guidelines along the follow-up, equivalent here to at least 500 metabolic equivalent minutes of PA per week. Cox regression adjusted for different models was used for the analyses, using age, body mass index, smoking and drinking status, hypertension, diabetes, hypercholesterolemia, and parental history of CVD. Results: Over a mean follow-up of 6.2 years, 439 CVD deaths occurred. Consistently meeting the PA guidelines, compared with not meeting, was associated with a 54% (95% confidence interval, 0.32–0.67) decreased risk of CVD mortality. After controlling for all potential confounders, the risk reduction was 47% (95% confidence interval, 0.36–0.77). Conclusions: Maintaining adherence to the PA guidelines produces substantial reductions in the risk of CVD deaths in men. Furthermore, discontinuing compliance with the guidelines may offset the beneficial effects on longevity.
Nivash Rugbeer, Demitri Constantinou, and Georgia Torres
Background: High-intensity training is comprised of sprint interval training (SIT) and high-intensity interval training (HIIT). This study compared high-intensity training with moderate-intensity continuous training (MICT) on cardiorespiratory fitness (CRF) and body fat percentage for overweight or obese persons. Methods: A systematic search of randomized controlled trials using the health science databases occurred up to April, 2020. Twenty-six studies were included for complete analysis. A total of 784 participations were analyzed. The unstandardized mean difference for each outcome measurement was extracted from the studies and pooled with the random effects model. Results: MICT was significantly better at improving CRF compared with SIT (mean difference = −0.92; 95% confidence interval, −1.63 to −0.21; P = .01; I 2 = 10%). Furthermore, there was no significant difference between MICT versus HIIT on CRF (mean difference = −0.52; 95% confidence interval, −1.18 to 0.13; P = .12; I 2 = 23%). There was no significant difference in body fat percentage between MICT versus HIIT and MICT versus SIT. Conclusions: MICT was significantly better at improving CRF than SIT in overweight or obese persons.
João R. Pereira, Dylan P. Cliff, Eduarda Sousa-Sá, Zhiguang Zhang, Jade McNeill, Sanne L.C. Veldman, and Rute Santos
Background: This study aimed to understand whether a higher number of sedentary bouts (SED bouts) and higher levels of sedentary time (SED time) occur according to different day types (childcare days, nonchildcare weekdays, and weekends) in Australian toddlers (1–2.99 y) and preschoolers (3–5.99 y). Methods: The SED time and bouts were assessed using ActiGraph GT3X+ accelerometers. The sample was composed of 264 toddlers and 343 preschoolers. The SED bouts and time differences were calculated using linear mixed models. Results: The toddlers’ percentage of SED time was higher on nonchildcare days compared with childcare days (mean difference [MD] = 2.3; 95% confidence interval, 0.7 to 3.9). The toddlers had a higher number of 1- to 4-minute SED bouts on nonchildcare days compared with childcare days. The preschoolers presented higher percentages of SED time during nonchildcare days (MD = 3.1; 95% confidence interval, 1.6 to 4.5) and weekends (MD = 1.9; 95% confidence interval, 0.4 to 3.4) compared with childcare days. The preschoolers presented a higher number of SED bouts (1–4, 5–9, 10–19, and 20–30 min) during nonchildcare days and weekends compared with childcare days. No SED times or bout differences were found between nonchildcare days and weekends, neither SED bouts >30 minutes on toddlers nor on preschoolers. Conclusion: The SED time and bouts seem to be lower during childcare periods, which means that interventions to reduce sedentary time should consider targeting nonchildcare days and weekends.
Aashirwad Mahajan, Satish Mahajan, and Swanand Tilekar
The primary objective of this pilot randomized controlled trial was to study the feasibility (recruitment and retention rates) for interval training and sleep hygiene (SH) in adults aged above 60 years. Thirteen out of 46 screened individuals from a home for older adults in Shirdi (Maharashtra, India) were randomly assigned by permuted block randomization to either an interval training with SH group (n = 6) or an SH alone group (n = 7). The authors measured sleep with the S+ sleep monitor manufactured by ResMed (USA) Pittsburgh Sleep Quality Index and quality of life with Short Form-12 health survey version 2. Interval training consisted of 8 weeks of stationary cycling, whereas SH consisted of lecture and handouts. Recruitment was 38.2%, retention was >80% for both the interventions, and there was one loss to follow-up in SH. Interval training and SH were feasible for older adults and supported a full-scale randomized controlled trial.
Lyndel Hewitt, Anthony D. Okely, Rebecca M. Stanley, Marjika Batterham, and Dylan P. Cliff
Background: Tummy time is recommended by the World Health Organization as part of its global movement guidelines for infant physical activity. To enable objective measurement of tummy time, accelerometer wear and nonwear time requires validation. The purpose of this study was to validate GENEActiv wear and nonwear time for use in infants. Methods: The analysis was conducted on accelerometer data from 32 healthy infants (4–25 wk) wearing a GENEActiv (right hip) while completing a positioning protocol (3 min each position). Direct observation (video) was compared with the accelerometer data. The accelerometer data were analyzed by receiver operating characteristic curves to identify optimal cut points for second-by-second wear and nonwear time. Cut points (accelerometer data) were tested against direct observation to determine performance. Statistical analysis was conducted using leave-one-out validation and Bland–Altman plots. Results: Mean temperature (0.941) and z-axis (0.889) had the greatest area under the receiver operating characteristic curve. Cut points were 25.6°C (temperature) and −0.812g (z-axis) and had high sensitivity (0.84, 95% confidence interval, 0.838–0.842) and specificity (0.948, 95% confidence interval, 0.944–0.948). Conclusions: Analyzing GENEActiv data using temperature (>25.6°C) and z-axis (greater than −0.812g) cut points can be used to determine wear time among infants for the purpose of measuring tummy time.
Victor E. Ezeugwu, Piush J. Mandhane, Nevin Hammam, Jeffrey R. Brook, Sukhpreet K. Tamana, Stephen Hunter, Joyce Chikuma, Diana L. Lefebvre, Meghan B. Azad, Theo J. Moraes, Padmaja Subbarao, Allan B. Becker, Stuart E. Turvey, Andrei Rosu, Malcolm R. Sears, and Valerie Carson
Background: Movement behaviors (physical activity, sedentary time, and sleep) established in early childhood track into adulthood and interact to influence health outcomes. This study examined the associations between neighborhood characteristics and weather with movement behaviors in preschoolers. Methods: A subset of Canadian Healthy Infant Longitudinal Development birth cohort (n = 385, 50.6% boys) with valid movement behaviors data were enrolled at age 3 years and followed through to age 5 years. Objective measures of neighborhood characteristics were derived by ArcGIS software, and weather variables were derived from the Government of Canada weather website. Random forest and linear mixed models were used to examine predictors of movement behaviors. Cross-sectional analyses were stratified by age and season (winter and nonwinter). Results: Neighborhood safety, temperature, green space, and roads were important neighborhood characteristics for movement behaviors in 3- and 5-year-olds. An increase in temperature was associated with greater light physical activity longitudinally from age 3 to 5 years and also in the winter at age 5 years in stratified analysis. A higher percentage of expressways was associated with less nonwinter moderate to vigorous physical activity at age 3 years. Conclusions: Future initiatives to promote healthy movement behaviors in the early years should consider age differences, neighborhood characteristics, and season.
David H. Perrin
In this essay, I reflect on my life and academic career, detailing my childhood, family background, education, and those who influenced me to study physical education and athletic training. My higher education started with a small college experience that had a transformative impact on my intellectual curiosity, leading to graduate degrees and, ultimately, a career in higher education. I chronicle my academic career trajectory as a non-tenure-track faculty member and clinician, tenured faculty member, department chair, dean, and provost. My personal and professional lives have been undergirded by a commitment to equity, diversity, and inclusion, with examples provided in this essay.
Nathalie Berninger, Gill ten Hoor, Guy Plasqui, and Rik Crutzen
Purpose : Physical activity (PA) is crucial for health, but there is insufficient evidence about PA patterns and their operationalization. The authors developed two algorithms (SPORTconstant and SPORTlinear) to quantify PA patterns and check whether pattern information yields additional explained variance (compared with a compositional data approach [CoDA]). Methods : To measure PA, 397 (218 females) adolescents with a mean age of 12.4 (SD = 0.6) years wore an ActiGraph on their lower back for 1 week. The SPORT algorithms are based on a running value, each day starting with 0 and minutely adapting depending on the behavior being performed. The authors used linear regression models with a behavior-dependent constant (SPORTconstant) and a function of time-in-bout (SPORTlinear) as predictors and body mass index z scores (BMIz) and fat mass percentages (%FM) as exemplary outcomes. For generalizability, the models were validated using five-fold cross-validation where data were split up in five groups, and each of them was a test data set in one of five iterations. Results : The CoDA and the SPORTconstant models explained low variance in BMIz (2% and 1%) and low to moderate variance in %FM (both 5%). The variance being explained by the SPORTlinear models was 6% (BMIz) and 9% (%FM), which was significantly more than the CoDA models (p < .001) according to likelihood ratio tests. Conclusion : Among this group of adolescents, SPORTlinear explained more variance of BMIz and %FM than CoDA. These results suggest a way to enable research about PA patterns. Future research should apply the SPORTlinear algorithm in other target groups and with other health outcomes.