Scale-up of the Australian Fans in Training (Aussie-FIT) men's health behaviour change program: a protocol for a randomised controlled hybrid effectiveness-implementation trial.

INTRODUCTION: Improving physical activity (PA) and healthy eating is critical for primary and secondary prevention of cardiovascular disease (CVD). Behaviour change programmes delivered in sporting clubs can engage men in health behaviour change, but are rarely sustained or scaled-up post trial. Following the success of pilot studies of the Australian Fans in Training (Aussie-FIT) programme, a hybrid effectiveness-implementation trial protocol was developed. This protocol outlines methods to: (1) establish if Aussie-FIT is effective at supporting men with or at risk of CVD to sustain improvements in moderate-to-vigorous PA (primary outcome), diet and physical and psychological health and (2) examine the feasibility and utility of implementation strategies to support programme adoption, implementation and sustainment. METHODS AND ANALYSIS: A pragmatic multistate/territory hybrid type 2 effectiveness-implementation parallel group randomised controlled trial with a 6-month wait list control arm in Australia. 320 men aged 35-75 years with or at risk of CVD will be recruited. Aussie-FIT involves 12 weekly face-to-face sessions including coach-led interactive education workshops and PA delivered in Australian Football League (Western Australia, Northern Territory) and rugby (Queensland) sports club settings. Follow-up measures will be at 3 and 6 months (both groups) and at 12 months to assess maintenance (intervention group only). Implementation outcomes will be reported using the Reach, Effectiveness, Adoption, Implementation, Maintenance framework. ETHICS AND DISSEMINATION: This multisite study has been approved by the lead ethics committees in the lead site's jurisdiction, the South Metropolitan Health Service Human Research Ethics Committee (Reference RGS4254) and the West Australian Aboriginal Health Ethics Committee (HREC1221). Findings will be disseminated at academic conferences, peer-reviewed journals and via presentations and reports to stakeholders, including consumers. Findings will inform a blueprint to support the sustainment and scale-up of Aussie-FIT across diverse Australian settings and populations to benefit men's health. TRIAL REGISTRATION NUMBER: This trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12623000437662).

Increases in muscle temperature by hot water improve muscle contractile function and reduce motor unit discharge rates.

PURPOSE: Examine the effects of 42°C hot-water immersion on muscle contraction function and motor unit discharge rates. Voluntary and evoked contraction assessments were examined first with a concomitant increase in the core and muscle temperature, and thereafter with increased muscle temperature but cooled core temperature. METHODS: Fifteen participants (24.9 ± 5.6 years) performed neuromuscular assessments before, after, and ~15-min after either 90-min of 42°C (hot) or 36°C (control) water immersion. Maximal voluntary contraction (MVC) assessment of knee extension was performed along with surface electromyography (sEMG) (vastus lateralis and medialis [VL, VM]) and voluntary activation level (VAL). Resting evoked twitch was elicited for peak torque and time to peak torque analysis. In addition, the VL and VM motor unit discharge rates (MUDR) were measured. RESULTS: After hot-water immersion (core temperature ↑1°C; muscle temperature ↑2.4°C), MVC torque and VAL decreased (p < 0.05). The sEMG (VL and VM) and peak twitch torque did not change (p > 0.05), while time to peak torque decreased (p = 0.007). The VL and VM MUDR decreased, showing a time effect, after both water immersion conditions (36 and 42°C) (p > 0.001). Fifteen minutes after the hot-water immersion (core temperature at baseline; muscle temperature ↑1.4°C), MVC torque returned to baseline, but VAL remained lower. The sEMG (VL and VM) remained unchanged. Peak twitch torque increased (p < 0.002) and time to peak torque remained lower (p = 0.028). The MUDR remained lower after both water immersion conditions (p < 0.05). CONCLUSION: Increased core temperature evoked by 42°C hot-water immersion decreases MVC torque and VAL. However, a passive increase in muscle temperature improved evoked muscle contractile function (i.e., time to peak torque [after] and peak twitch torque [~15 min after]). Moreover, a passive increase in muscle temperature reduced the required MUDR to attain the same torque.

Predicting Lactate Threshold With Rate of Perceived Exertion in Young Competitive Male Swimmers.

The purpose of this study was to verify the effectiveness of the rate of perceived exertion threshold (RPET) for predicting young competitive swimmers' lactate threshold (LT) during incremental testing. We enrolled 13 male athletes (M age = 16, SD = 0.6 years) in an incremental test protocol consisting of eight repetitions of a 100-meter crawl with 2-minute intervals between each repetition. We collected data for blood lactate concentration ([La]) and Borg scale rate of perceived exertion (RPE) at the end of each repetition. The results obtained were: M RPET = 4.98, SD = 1.12 arbitrary units (A.U.) and M lactate threshold = 4.24, SD = 1.12 mmol.L-1, with [La] and RPE identified by the maximal deviation (Dmax) method without a significant difference (p > 0.05) and large correlations between DmaxLa and DmaxRPE at variables for time (r = 0.64), velocity (r = 0.67) and percentage of personal best time (PB) (r = 0.60). These results suggest that RPET is a good predictor of LT in young competitive swimmers.

A passive increase in muscle temperature enhances rapid force production and neuromuscular function in healthy adults.

OBJECTIVE: To test the effects of hot-water immersion on the rapid force production and parameters of neuromuscular function in healthy adults. DESIGN: Cross-sectional study. METHODS: Fifteen healthy adults (24.9±5.6 years; 178±11.4cm; 72.8±16.2kg) performed neuromuscular assessments before, after and ∼15min after either 90min of 42°C (hot) or 36°C (sham-condition) water immersion (lower body). Knee extensors rate of torque development (RTD) was measured during explosive voluntary contraction in the interval of 0-50ms (RTDV50) and 0-150ms (RTDV150) and during electrically-evoked contractions by single twitches (RTDtwitch) and low- and high-frequencies doublets (RTD20Hz and 100Hz). Rate of EMG rise (RER) was calculated for voluntary contractions and half-relaxation time (HRT) and electromechanical delay (EMD) was measured during single twitches. RESULTS: After the hot-water immersion (when rectal and muscle temperature were elevated [↑1°C and ↑2.4°C, respectively]), RTDV50, RTD20Hz and RTD100Hz significantly increased and HRT decreased when compared to baseline and sham-condition (p<0.05). Approximately 15min after the hot-water immersion (when muscle temperature was still higher [↑1.4°C], but rectal temperature at baseline level), RTDV50 remained higher and RTDtwitch presented higher values than baseline and sham-condition. The RTD20Hz and RTD100Hz showed further increases compared to post hot-water immersion trials. HRT showed no changes compared to post water immersion, but the EMD presented lower values than baseline and sham-condition. No changes were observed for RTDV150 and RER at any moment. CONCLUSION: Increased muscle temperature provoked by 42°C hot-water immersion increases the early phase of the RTD (<70ms) (voluntary and evoked) and decreases HRT and EMD of the knee extensors.

Effects of passive heating intervention on muscle hypertrophy and neuromuscular function: A preliminary systematic review with meta-analysis.

Passive heating has been therapeutically used to treat a range of health conditions. Further, this intervention presents as a potential exercise mimetic strategy showing acute and chronic effects on skeletal muscle adaptation and neuromuscular systems. This systematic review and meta-analysis aimed to synthesise the existing evidence on the effects of passive heating on muscle hypertrophy and neuromuscular function. Seven databases were searched (i.e., PubMed, Web of Science, Scopus, CINAHL, EMBASE, Cochrane, and SPORTDiscus) from 1937 to October 2019. Eligible studies included original papers using healthy animals or human samples (≥18 years; both sexes) that have used a control group or condition. Ten original articles were included in this review and four in the meta-analysis. The meta-analysis detected an increase in muscle mass in animal samples seven days after passive heating (I2 = 65%, P < 0.01). The systematic review showed preliminary evidence that repeated passive heating exposures may promote muscle hypertrophy in animals and humans. Moreover, augmented muscle strength (involuntary and voluntary) may be observed after long-term passive heating (animals and humans) and increases in corticospinal excitability in humans after a single passive heating session. Passive heating has shown some potential benefits for skeletal muscle mass gain and muscle force improvement. Therefore, it is plausible to suggest that passive heating might be a worthwhile alternative to be recommended as an exercise mimetic for those people who lack or are unable to complete sufficient exercise.

Muscle temperature kinetics and thermoregulatory responses to 42 °C hot-water immersion in healthy males and females.

PURPOSE: To determine the vastus lateralis muscle temperature kinetics during and after passive heating, to exam the effect of sex on thermoregulatory responses, and the thermal safety and tolerance of the 42 °C hot-water immersion protocol. METHODS: Thirty participants (15 males, 15 females) underwent a 2 h 42 ºC hot-water immersion to the waist level. Vastus lateralis, rectal and skin temperature, thermal sensation, heart rate and blood pressure (BP) were measured during the passive heating and recovery period. Participant recovery was monitored until muscle temperature returned to baseline. RESULTS: Vastus lateralis temperature increased to a maximal value of 39.0 ± 0.11 °C (P < 0.001), reaching a plateau after ~ 83.5 min of hot-water immersion and returning to baseline after ~ 115.8 min of recovery. Despite the anthropometric differences between males and females (e.g., height, body mass, body fat %, and fat thickness; P < 0.05), thermoregulatory responses showed no differences between sexes (P > 0.05). No change was found in systolic BP (~ 117 mmHg; P = 0.061). Peak rectal temperature (38.8 ± 0.14 °C; P < 0.001), heart rate (~ 100 bpm; P < 0.001), and diastolic BP (↓ ~ 13 mmHg; P < 0.001) during the hot-water immersion indicated the safety of the protocol. While skin temperature (~ 35.4 °C; P < 0.001) and thermal sensation (~ 5.95 AU; P < 0.001) confirmed protocol tolerance. CONCLUSION: These data demonstrate lower-body 42 °C hot-water immersion to increase vastus lateralis temperature and plateau ~ 2.8 °C above baseline. This amplitude of muscle temperature change aligns with reported cellular adaptation and muscle growth. Thermal strain incurred from this protocol appears safe and tolerable, positioning it well for health-related prescription.

Correlates of physical activity in fifth-grade students in Ho Chi Minh City, Vietnam.

Studies investigating correlates of physical activity (PA) using objective PA measurements among primary school-aged children are limited in Asia, particularly Vietnam. This study examined psychosocial and environmental factors associated with PA among fifth-grade students in eight primary schools in Ho Chi Minh city, Vietnam. Bivariate analyses showed that for every month increase in students' age, an increase of 66 steps/day (p<0.05) was found; boys had 1442 more steps/day than girls (p<0.001); and students from lower income households had 1169 steps/day less than those from higher income households (p<0.01). For every unit increase in self-efficacy, perceived social influences, intention to be physically active, and parental support for PA, an increase of 220, 200, 522, and 117 steps/day (p<0.01) was found respectively. In multivariable analysis, only intention and parental support for PA remained significant (p<0.01). About 21% of variation in daily steps was explained by demographic characteristics and an additional 13% by psychosocial influences. In conclusion, intention to be physically active and parental support are important factors and should be considered when designing PA interventions in school/community-based settings.

Psychometric properties of questionnaires to measure social ecological influences in Vietnamese children.

Physical activity data in primary school-aged children are limited in Vietnam. Although tools to measure social ecological influences on physical activity are validated in English, they are not available in Vietnamese. Due to cultural and contextual differences, their psychometric properties need to be tested. Five scales were translated into Vietnamese and evaluated for internal consistency and test re-test reliability, including self-efficacy, perceived social influences, and beliefs self-administered by students, and parental support for physical activity and parental perceived safety of the neighbourhood, self-administered by parents. Compared to the original scales, two items from the parental perceived neighbourhood safety were removed due to the cultural context. Another item of the self-efficacy scale was also removed as it correlated poorly with the other items in the scale at both administrations. The adjusted scales were found to be reliable and appropriate for use among students and parents to measure social ecological influences on physical activity in the Vietnamese context.

Time-course of changes in indirect markers of muscle damage responses following a 130-km cycling race / Comportamento das respostas dos marcadores indiretos de dano muscular após uma competição de ciclismo de 130-km

Abstract The purpose of the present investigation was to identify the effects of a 130-km cycling race on indices of biochemical indirect markers of muscle damage and muscle soreness responses during a 72-hour recovery period. Fifteen endurance-trained male cyclists which were competing for more than 2 years and were involved in systematic training at least of 3 days/wk underwent a collection of indirect biochemical markers of muscle damage (CK, LDH, Myo) and delayed onset of muscle soreness (DOMS), at five different moments of data collection: before (PRE) and immediately after (POST) a 130-km cycling race, and 24, 48, 72 hours following the cycling race. CK and LDH plasma concentrations significantly increased POST-race (p < 0.001) and remained high throughout the 72 hour recover period (CK: p < 0.05; LDH: p < 0.001). Myo increased significantly POST-race (p < 0.001) and returned to the PRE-race values 24 hours thereafter (p < 0.05). DOMS increased significantly POST-race (p < 0.001) and returned to the PRE-race values at 48 hours after (p > 0.05). A 130-km cycling race has a noteworthy effect on indices of biochemical indirect markers of muscle damage and muscle soreness responses, indicating that 72 hour recovery period do not seems to be enough for long-distance cyclist, and reinforce the propositions of scientific literature about the need of a sufficient recovery period for cycling endurance athletes.

Resumo O objetivo do presente estudo foi identificar os efeitos de uma competição de ciclismo de 130-km nos índices de marcadores bioquímicos indiretos de dano muscular e na dor muscular durante um período de 72 horas de recuperação. Quinze ciclistas do sexo masculino que estavam em treinamento competitivo por mais de dois anos e que estavam em treinamento sistemático, pelo menos três dias por semana, foram submetidos à coleta de marcadores bioquímicos indireto de dano muscular (CK, LDH e Mioglobina) e dor muscular em cinco momentos distintos de coleta: antes, depois, 24, 48 e, 72 horas após uma competição de ciclismo. A CK e a LDH aumentaram imediatamente após a corrida (p < 0,001) e mantiveram-se elevadas durante as 72 horas de recuperação (CK: p < 0,05; LDH: p < 0,001). A Mioglobina aumentou logo após a competição (p < 0,001) e retornou aos valores basais 24 horas após (p < 0,05). A dor muscular aumentou logo após a competição (p < 0,001) e retornou aos valores basais após 48 horas de recuperação (p > 0,05). Uma competição de ciclismo de 130-km teve efeitos notáveis sobre os índices de marcadores bioquímicos indiretos de lesão muscular e dor muscular, indicando que um período de 72 horas de recuperação pode não ser o suficiente para ciclistas de longa distância, isto também reforça as proposições da literatura científica sobre a necessidade de um período de recuperação suficiente para os atletas de ciclismo de fundo.