Combined training,FNDC5/irisin levels and metabolic markers in obese men: A randomised controlled trial

The effects of training on FNDC5/irisin and its association with fitness and metabolic marker improvements induced by training have been poorly investigated in humans. Thus, the present study assessed the effects of combined training (CT) on FNDC5/irisin levels, metabolic markers and fitness adaptations in obese men. Middle-age obese men (age 49.13?±?5.75, body mass index (BMI) 30.86?±?1.63) were randomly distributed in the CT group (n?=?12) and control group (CG n?=?10). The CT consisted of strength followed by aerobic training, 3 times/week, for 24 weeks. Body composition, physical fitness, plasma FNDC5/irisin, biochemical markers and metabolic scores/index were evaluated. CT maintained FNDC5/irisin levels (µg/mL) (pre: 4.15?±?0.32, post: 4.21?±?0.32; p?=?.96) and improved body composition, metabolic and physical fitness markers. In the CG, decreased FNDC5/irisin (µg/mL) (pre: 4.36?±?0.23, post: 3.57?±?0.94; p?=?.01) and reduced strength (supine exercise/kg) (pre: 71?±?14.7, post: 60.1?±?14.05; p?<?.01) were observed, along with a trend to increase HOMA-IR (pre: 2.63?±?1.11, post: 3.14?±?1.27; p?=?.07) and other indicators of metabolic deterioration. An inverse correlation was found between the change (Δ%) in levels of FNDC5/irisin and Δ% glucose, Δ% total cholesterol, Δ% triglycerides and Δ% waist circumference, in addition to a positive relation with Δ% muscle strength. In conclusion, CT maintained FNDC5/irisin levels and provided metabolic and fitness benefits. The correlation between FNDC5/irisin changes and metabolic parameters, as well as the FNDC5/irisin reduction associated with fitness and metabolic worsening in the CG, suggests a relationship between FNDC5/irisin and a healthy metabolic status in humans.     

Exercise training modifies walking kinematics and energy cost in obese adolescents: A pilot controlled trial

Abstract

The aim of this study was to investigate the effects of a weight loss intervention based on physical exercise on the relationship between energy cost and stride frequency during walking in obese teenagers. Participants aged 13–16 years old were assigned to a training (n?=?14) and control (n?=?10) groups. During eight weeks, the training group performed three 60-min weekly sessions of high-intensity intermittent activities coupled with aerobic training. Body composition, gait parameters and energy cost during 4-min walking bouts at participants’ most comfortable speed and preferred stride frequency (PSF), PSF-10%, PSF?+?10%, PSF-20% and PSF?+?20% were measured before and after intervention. The effects of training and stride frequencies on the energy cost of walking were analysed by an ANOVA with repeated measures. The main results showed that the exercise intervention induced a significant increase in walking speed (+23.2%), and significant decreases in body mass (?1.4%), body fat percentage (?2.1%) and energy cost of walking at various frequencies (decreases ranging from ?10.5% to ?20.4%, p?<?.05). In addition, significantly greater decreases were shown at high frequencies (p?<?.05). No significant differences were shown in the control group (p?>?.05). These results suggest that this type of training is beneficial to reduce walking energy cost of obese teenagers, in particular at high frequencies. This should improve their well-being during daily activities.     

Sport-based physical activity intervention on body weight in children and adolescents: a meta-analysis

Controversial results reported in past research pertaining to the effectiveness of sport-based physical activity interventions on weight loss. The purpose of this study was to assess the impact of sport-based physical activity intervention on body weight in children and adolescents using a meta-analysis. Academic Search Complete, Education Source, ERIC, Medline, ProQuest, PsycINFO and SportDiscus databases were searched from January 2000 to April 2015. Eighteen studies met following inclusion criteria: sport-based intervention studies; subjects aged 6–18 years; reported body weight; published in peer-reviewed journals written in English. The mean intervention duration was 17.72 weeks. The overall effect size (ES) was 0.52 (Cohen’s d (ES) = 0.52, 95% CI = 0.08, 0.95, P = 0.021), using a random effects model. Moderator analyses results showed that the Q statistic for the sport type (individual sport or team sport, Qbetween (Q_b) = 14.52, df = 1, P = 0.001) and diet control (Qbetween (Q_b) = 8.85, df = 1, P = 0.001), explained the heterogeneity of ESs. Our study showed that there was a moderate overall effect of sport-based physical activity intervention on body weight reduction. The team sport type (ES = 1.05, 95% CI = 0.44, 1.66) and diet control group (ES = 0.84, 95% CI = 0.26, 1.41) appeared to be more effective in reducing body weight.     

Differential time responses in inflammatory and oxidative stress markers after a marathon: An observational study

ABSTRACT

Acute and adaptive changes in systemic markers of oxidatively generated nucleic acid modifications (i.e., 8-oxo-7,8-dihydro-2?-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo)) as well as inflammatory cytokines (i.e., C-reactive protein, interleukin-6, interleukin-10, and tumour necrosis factor alpha), a liver hormone (i.e., fibroblast growth factor 21 (FGF21)), and bone metabolism markers (sclerostin, osteocalcin, C-terminal telopeptide, and N-terminal propeptide of type 1 procollagen) were investigated following a marathon in 20 study participants. Immediate changes were observed in inflammatory cytokines, FGF21, and bone metabolism markers following the marathon. In contrast, no immediate changes in urinary excretion of 8-oxodG and 8-oxoGuo were evident. Four days after the marathon, decreased urinary excretion of 8-oxodG (-2.9 (95% CI -4.8;-1.1) nmol/24 h, P < 0.01) and 8-oxoGuo (-5.8 (95% CI -10.3;-1.3) nmol/24 h, P = 0.02) was observed. The excretion rate of 8-oxodG remained decreased 7 days after the marathon compared to baseline (-2.3 (95%CI -4.3;-0.4) nmol/24 h, P = 0.02), whereas the excretion rate of 8-oxoGuo was normalized. In conclusion marathon participation immediately induced a considerable inflammatory response, but did not increase excretion rates of oxidatively generated nucleic acid modifications. In fact, a delayed decrease in oxidatively generated nucleic acid modifications was observed suggesting adaptive antioxidative effects following exercise.     

Effects of strengthening and stretching exercise programmes on kinematics and kinetics of running in older adults: a randomised controlled trial

The aim of this study was to investigate the effects of strengthening and stretching exercises on running kinematics and kinetics in older runners. One hundred and five runners (55–75 years) were randomly assigned to either a strengthening (n = 36), flexibility (n = 34) or control (n = 35) group. Running kinematics and kinetics were obtained using an eight-camera system and an instrumented treadmill before and after the eight-week exercise protocol. Measures of strength and flexibility were also obtained using a dynamometer and inclinometer/goniometer. A time effect was observed for the excursion angles of the ankle sagittal (P = 0.004, d = 0.17) and thorax/pelvis transverse (P < 0.001, d = 0.20) plane. Similarly, a time effect was observed for knee transverse plane impulse (P = 0.013, d = 0.26) and ground reaction force propulsion (P = 0.042, d = ?0.15). A time effect for hip adduction (P = 0.006, d = 0.69), ankle dorsiflexion (P = 0.002, d = 0.47) and hip internal rotation (P = 0.048, d = 0.30) flexibility, and hip extensor (P = 0.001, d = ?0.48) and ankle plantar flexor (P = 0.01, d = 0.39) strength were also observed. However, these changes were irrespective of exercise group. The results of the present study indicate that an eight-week stretching or strengthening protocol, compared to controls, was not effective in altering age-related running biomechanics despite changes in ankle and trunk kinematics, knee kinetics and ground reaction forces along with alterations in muscle strength and flexibility were observed over time.     

Effects of movement velocity and training frequency of resistance exercise on functional performance in older adults: a randomised controlled trial

Objectives: To investigate the effects that high-velocity, low-load (HVLL) and low-velocity, high-load (LVHL) resistance exercise, performed once or twice-weekly, have on indices of functional performance (primary outcome), maximal strength, and body composition (secondary outcomes) in older adults.

Methods: In a randomised, controlled, multi-armed, parallel design, 54 moderately-highly active, but resistance exercise naïve older adults (aged 60–79 years), attended baseline and post-10-week intervention assessment sessions. Physical and functional assessments were completed, and predicted one-repetition maximums (1-RM) were obtained for eight exercises. Participants were then randomised into one of five conditions: HVLL once-weekly (HVLL1: n?=?11) or twice-weekly (HVLL2: n?=?11), LVHL once-weekly (LVHL1: n?=?10) or twice-weekly (LVHL2: n?=?11), no-exercise control condition (CON: n?=?11). The HVLL conditions completed 3 sets of 14 repetitions at 40% 1-RM and the LVHL conditions, 3 sets of 7 repetitions at 80% 1-RM. In total, 50 participants completed all testing and were included in analyses.

Results: Only LVHL2 improved 30-sec chair stand performance (p?=?.035; g?=?0.89), arm curls (p?=?.011; g?=?1.65) and grip-strength (p?=?.015; g?=?0.34) compared to CON. LVHL2 improved maximal strength compared to CON for 7/8 exercises (p?p?Conclusion: Possibly due to the lower intensity nature of the HVLL conditions, LVHL, twice-weekly was most beneficial for improving functional performance and strength in moderately-highly active older adults. Therefore, we recommend that exercise professionals ensure resistance exercise sessions have sufficient intensity of effort and volume, in order to maximise functional performance and strength gains in older adults.     

Student outcomes of the physical education and physical literacy (PEPL) approach: a pragmatic cluster randomised controlled trial of a multicomponent intervention to improve physical literacy in primary schools

ABSTRACT

Background: Health organisations such as the United Nations continue to place an expectation on school physical education (PE) programmes and wider school strategies to ensure students develop physical literacy and receive the well-established benefits of meeting physical activity guidelines. Barriers to meet this expectation such as lack of trained PE teachers, lack of time and greater emphasis on academic achievement are ongoing challenges to schools. The purpose of this study was to evaluate the impact of the multi-component Physical Education Physical Literacy (PEPL) intervention, designed to improve students’ fundamental movement skill, perceived physical abilities and level of physical activity.

Method: A qualified PE teacher implemented the PEPL intervention across seven schools, and another seven schools formed a control group as part of a randomised cluster-based trial. Grade 5 students (N?=?318, age 10.4 years?±?SD 0.4) completed assessments of physical activity, fundamental movement skill, attitudes towards PE, and self-perceptions of physical abilities before and after a 33-week intervention. Intervention effects were examined using general linear mixed models. Post-intervention focus groups with students were used to develop insights into experiences and outcomes.

Results: With no significant gender interactions, the PEPL approach led to enhanced object control skills (β?=?1.62; SE?=?0.61; p?=?0.008), with little evidence of any other fundamental movement skill improvements in excess of those in the control group. There was also modest evidence for an effect on accelerometer measured moderate-to-vigorous physical activity (MVPA) during school time (β?=?4.50; SE?=?2.39; p?=?0.058), but this was not accompanied by any significant intervention effect over the entire week. Questionnaires indicated students in the PEPL programme became less satisfied with their own sporting ability (β?=??0.20; SE?=?0.08; p?=?0.013) but qualitative data analyses suggested that they enjoyed the PEPL approach experience, becoming more motivated and confident in their physical abilities.

Conclusions: Evidence of enhanced object control skill, increased confidence and motivation to be physically active, and moderate evidence of more MVPA during school time, indicate that the introduction of the PEPL approach contributed to the development of student physical literacy. A decrease in perceived sporting competence warrants greater attention on student’s self-perceptions in future iterations of the intervention.

Trial registration: Australian New Zealand Clinical Trials Registry identifier: ACTRN12615000066583.     

Teacher and school outcomes of the Physical Education and Physical Literacy (PEPL) approach: a pragmatic cluster randomised controlled trial of a multicomponent intervention to improve physical literacy in primary schools

ABSTRACT

Background: Physical education (PE) can be considered the centrepiece of school physical literacy (PL) programs, but ineffective lessons or an absence of PE across the public primary school system has raised concern. This study aimed to evaluate the implementation, acceptability and impact of teacher delivery of PE as part of a multicomponent Physical Education Physical Literacy (PEPL) approach, designed to improve classroom teachers’ provision of PE and PL opportunities within a cluster of suburban primary schools.

Method: Within a pragmatic randomised cluster-based trial with mixed methods, a PEPL coach was appointed to seven schools for one school year, with another seven schools continuing their usual practice as the control group. The coach’s role was to support and professionally develop classroom teachers to teach PE and to create opportunities that develop PL inside and outside the school environment. Focusing on Grade 5 teachers, the implementation, acceptability and teacher impact were assessed using direct observations of PE teaching style, a daily log kept by the coach and interviews with principals and teachers.

Results: The PEPL coach visited each school on average once a week for the 33 available weeks of the school year. There were several positive effects for teachers and schools. With no classroom teacher initially taking PE or classroom physical activity breaks, all seven teachers regularly introduced a PE lesson and activity breaks into their weekly schedule. PE class instructional time increased (intervention; +4.8 vs. control; ?3.5 min/lesson; β?=?1.69; SE?=?0.76; p?=?.05), with lessons of greater duration (intervention; +8.6 vs. control +1.9 min/lesson; β?=?1.14, SE?=?0.58, p?=?.05) and moderate and vigorous physical activity increased 5.7 min in intervention classes (p?<?.05). The PEPL coach introduced regular physical activities before and after school and linked the schools with a national sports coaching scheme. Interviews indicated that the PEPL approach was both valued and well-accepted by staff, that classroom teacher confidence to teach PE increased and that principals perceived a shift toward a school ‘culture’ of physical activity.

Conclusions: Well-received by classroom teachers and principals, the PEPL approach resulted in classroom teachers introducing both PE and activity breaks into their weekly teaching program and schools were linked to external sport coaching programs. These effects suggest that the PEPL approach enhanced opportunities for the development of physical literacy in this suburban primary school setting.

Trial registration: Australian New Zealand Clinical Trials Registry identifier: ACTRN12615000066583.