Impact of a physical education-based behavioural skill training program on cognitive antecedents and exercise and sport behaviour among adolescents: a cluster-randomized controlled trial

ABSTRACT

Background: School-based physical education has been associated with a multitude of potential learning outcomes. Representatives of a public health perspective suggest that promoting physical activity in and outside the context of school is an important endeavour. While the importance of behavioural skill training to improve (motor) learning is well documented in both general and physical education, the promotion of behavioural skills to foster physically active lifestyles constitutes a rather neglected area in physical education research.

Purpose: To examine whether a standardized physical education-based behavioural skill training program has the potential to positively impact on adolescents’ self-reported exercise and sport participation, as well as cognitive antecedents involved in the regulation of exercise and sport behaviour.

Research design: Cluster-randomized controlled trial.

Methods: A sample of 143 secondary school students (50% girls, aged 14–18 years) attending academic high schools in German-speaking Switzerland were assigned class-wise to the intervention (behavioural skill training) and control condition (conventional physical education lessons). Data were assessed prior and after completion of the 7-week intervention program, which was composed of four 20-min lessons and two reflection phases. Exercise and sport behaviour and cognitive antecedents (exercise/sport intention, motivation, implementation intentions, coping planning, self-efficacy) were assessed via self-reports. A multilevel mixed effects linear regression procedure was used to test the main hypotheses. The regression analyses were adjusted for clustering of school classes, and controlled for baseline levels of the outcome measure and potential confounders.

Results: Compared to a control condition, the intervention program resulted in significant improvements with regard to introjected motivation (p?<?.05), coping planning (p?<?.001) and self-efficacy (p?<?.01). The intervention also had a positive impact on adolescents’ self-reported sport/exercise behaviour (p?<?.001). Improvements in exercise/sport intention (p?<?.05), coping planning (p?<?.01), and self-efficacy (p?<?.01) were associated with increased levels of self-reported exercise/sport participation.

Conclusion: Behavioural skill training as part of compulsory physical education has the potential to improve cognitive antecedents of exercise and sport behaviour and to foster adolescents’ exercise and sport participation. Enhancing behavioural skills might be one way in which school physical education can contribute to the creation of more physically active lifestyles among adolescents.     

Exercise Recovery,Lactate Removal,and Subsequent High Intensity Exercise Performance

Abstract

In order to examine the effects of different recoveries from high intensity short duration exercise on lactate removal and subsequent performance, 11 subjects completed 8 experimental sessions. Each subject completed an initial all-out pedaling task against 5.5 kg resistance (Monark bicycle ergometer) for 1 min followed by a randomly assigned recovery pattern and a repeat of the all-out exercise task. The main effects examined were active (1.0 kg, 60 rpm) vs passive recovery, inhalation of inhalation of oxygen vs room air during recovery, and 10- vs-20-min duration of recovery. Pedal revolutions were analyzed on a 6- by 6-sec and on a cumulative basis. Blood lactate concentrations were determined during rest, the 3rd–4th, 9th–10th, and 19th–20th min of recovery. Results revealed significant main effects for active vs passive recovery and for 10- vs 20-min recovery, with active and 20-min recovery resulting in significantly higher postrecovery pedal revolutions (p < .001) and enhanced rates of lactate removal during recovery (p < .001). Oxygen inhalation during recovery had no effect on postrecovery performance or lactate removal (p > .05). The correlation between blood lactate levels at the end of recovery and pedal revolutions on the postrecovery exercise task was only r = -.19, suggesting that factors other than lactate removal are critical for subsequent performance.     

Relationship between before-to-after-exercise feeling state changes and exercise session attendance over 14 weeks: Testing principles of Operant Conditioning

Abstract

A preliminary field study was conducted to estimate relationships between changes in feelings states occurring from before to after 20- to 30-min bouts of moderate cardiovascular exercise, and two measures of adherence to exercise in 66 adults (M _age=38?yrs, 30% males) initiating regimens of 3x/week. Positive pre- to post-exercise changes in participants’ feeling state scores ranged from 0 to 100% (M=73.2%, SD=28.8). Significant positive correlations were found between percentage of positive changes and exercise session attendance (r=0.36, p=0.003), and number of days of adherence to exercise (r=0.37, p=0.002), over 14 weeks. Results were interpreted as supporting principles of operant conditioning, and the possibility of exercise-induced feeling changes having direct reinforcing and punishing properties on the behavior of exercise in adults initiating programs. Accounting for identified correlates of exercise maintenance was suggested for extensions of this research. Applied uses of the abbreviated feeling state measure adapted for this research were suggested, after sufficient replication.     

The effects of maximal and submaximal arm crank ergometry and cycle ergometry on postural sway

Abstract

This study aimed to determine whether arm crank ergometry (ACE) disturbed postural sway to the same extent as cycle ergometry (CE). Nine healthy, none specifically trained adults undertook posturographic tests before and after five separate exercise trials consisting of: two incremental exercise tests to exhaustion for ACE and CE to examine postural sway responses to maximal exercise and to determine peak power output (W_max); two subsequent tests of 30 min duration for ACE and CE at a relative workload corresponding to 50% of the ergometer-specific W_max (ACE_rel; 53 ± 8 W and CE_rel; 109 ± 16 W). A final CE trial was performed at the same absolute power output (CE_abs) as the submaximal ACE trial to match absolute exercise intensity (i.e., 53 ± 8 W). The centre of pressure (COP) displacement was recorded using a force platform before, immediately after exercise and during a 30-min recovery period. ACE had no effects on postural sway (P > 0.05). An increase in mediolateral COP displacement was observed following maximal CE only (P = 0.001), while anteroposterior COP displacement and COP path length increased following maximal and submaximal CE (P < 0.05). These differences in postural sway according to exercise mode likely stem from the activity of postural muscles when considering that CE recruits lower limb muscles involved in balance. This study provides evidence of an exercise mode which does not elicit post-exercise balance impairments, therefore possesses applications to those at an increased risk of falling.     

Grading in Portuguese secondary school physical education: assessment parameters,gender differences and associations with academic achievement

ABSTRACT

Background: Assessment is crucial for the quality of teaching and learning in physical education (PE). Currently little is known about the students’ level of achievement in PE and about the parameters used for calculating the PE grades. Although there is evidence that boys are more active outside school than girls and participate more in organized sports, few studies have examined possible differences between genders in PE achievement. Furthermore, despite the current interest in the relationship between motor competencies and cognitive functioning, limited research has examined if PE grades are associated with academic achievement.

Purpose: Considering the lack of information on the current level of students’ success in PE, the main aim of this study is to examine the PE grades of Portuguese students in secondary school. Specifically, this study analysis the level of students’ achievement in PE, the relation of PE grades with other school subjects’ grades, compares the PE grades between boys and girls, and presents the PE summative assessment parameters used in schools.

Method: Participants were 1936 students (57% girls) from the 10th, 11th and 12th grades (16.8?±?1.3 years old) attending eleven Portuguese secondary schools. Information was gathered on their grades in PE and in the other school subjects at the end of the school year. Information on the specific assessment parameters used in each school was also collected.

Results: The average grades in PE were 14.9?±?2.3 points (20-point scale). Only ～1% of students with a final PE grade had a negative performance (<10 points). PE grades were relatively higher than in most of the other school-subjects and for most students (68.7%) the PE classification raised their overall average grade. The level of correlation between grades in PE and in other school subjects was statistically significant (r's?=?.13 to .29, p?<?.05) although lower than that between grades in the other school subjects (r's?=?.44 to .84, p?<?.01). There were significant differences between girls’ and boys’ grades in PE (14.3?±?2.3 and 15.9?±?2.1 points, respectively). The school assessment parameters prioritize physical performance over participation and attitude.

Conclusion: The Portuguese students’ level of achievement in PE seems to be very satisfactory. However, as boys have higher grades than girls it is urgent to find appropriate strategies to tackle this problem. The associations found between PE grades and academic achievement could have relevant repercussions considering the current debate about the status of PE and about the relationship between motor and cognitive competencies. It is also relevant that the schools’ summative assessment parameters are based mainly on skill mastery and not on effort and participation. This study provided a brief glance into some aspects of the assessment of PE in Portugal and is it is desirable that future investigations examine the teacher's assessment practices.     

Validity of Activity Trackers in Estimating Energy Expenditure During High-Intensity Functional Training

ABSTRACT

Purpose: The purpose of this study was to evaluate the agreement of five commercially available accelerometers in estimating energy expenditure while performing an acute bout of high-intensity functional training (HIFT). Methods: Participants (n = 47; average age: 28.5 ± 11.6 years) consisted of recreationally active, healthy adults. Each participant completed a session of HIFT: a 15-minute workout consisting of 12 repetitions each of air-squats, sit-ups, push-ups, lunges, pull-ups, steps-ups, and high-knees; performed circuit-style by completing as many rounds as possible. During this session, each participant wore the Cosmed K4b2 portable metabolic analyzer (PMA) and five different accelerometers (ActiGraph GT3X, Nike Fuelband, Fitbit One, Fitbit Charge HR, and Jawbone UP Move). Results: Four of the five activity trackers reported lower (p < .05) total EE values compared to the PMA during the acute bout of HIFT. The waist-mounted device (ActiGraph, 182.55 ± 37.93 kcal) was not significantly different from, and most closely estimated caloric expenditure compared to the PMA (144.99 ± 37.13 kcal) (p = .056). A repeated-measures ANOVA showed that all activity trackers were significantly different from the reference measure (PMA) (p < .05). Systematic relative agreement between the activity trackers was calculated, exhibiting a significant ICC = 0.426 (F [46,230] = 5.446 [p < .05]). Conclusion: The wrist- and hip-mounted activity trackers did not accurately assess energy expenditure during HIFT exercise. With the exception of the ActiGraph GT3X, the remaining four activity trackers showed inaccurate estimates of the amount of kilocalories expended during the HIFT exercise bout compared to the PMA.     

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.     

Interval exercise induces milder respiratory responses compared to continuous exercise

ABSTRACT

The purpose of this study was to explore the respiratory response of acute interval and continuous exercise (CE) of low and high intensity. Fourteen recreational athletes (7 men and 7 women; VO₂max = 35.7 ± 6.1 mlkg^–1min^–1) performed a bout of continuous and a bout of interval exercise (IE) both consisted of 5-min cycling at low intensity [80% of the power output (W) of the predetermined gas exchange threshold (GET) (80%W_GET)] and 5-min cycling at high intensity {W_GET plus the work rate corresponding to 50% of the difference between peak power output (PPO) at oxygen uptake (VO₂max) test and the W_GET [W_GET + 0.50 Δ(PPO – W_GET)]}. CE compared to IE induced significant higher heart rate and ventilation as well as significant higher levels of mouth occlusion pressure for 0.1 s (P_0.1) (P < 0.05) during low and high intensities. Our results indicate that CE stimulates respiration more than IE when the exercise is performed at the same relative intensity.     

Finnish students’ enjoyment and anxiety levels during fitness testing classes

ABSTRACT

Background: Fitness testing is a commonly applied learning and teaching practice implemented in both secondary and elementary school physical education (PE). Many teachers believe that by using a variety of different tests, they are able to provide students with feedback regarding their fitness status, and furthermore, increase students’ willingness to be physically active later in their lives. However, empirical evidence concerning students’ affective responses during fitness testing classes is limited.

Purpose: The primary aim of the study was to investigate whether students’ perceptions of enjoyment and anxiety differed between two different types of fitness testing classes and PE in general. In addition, the measurement invariances over time and between Grade 5 (aged 11–12) and Grade 8 (aged 14–15) groups were determined.

Method: A total sample of 645 Finnish Grade 5 (N?=?328, 50% boys, mean age?=?11.2, SD?=?0.36) and Grade 8 students (N?=?317, 47% boys, mean age?=?14.2, SD?=?0.35) participated in the study. Series of multi-group confirmatory factor analyses were conducted to test the level of measurement invariance between general PE and fitness testing classes, and between age groups. Strict factorial invariance was supported for both enjoyment and anxiety scales allowing for latent mean comparisons. Latent mean differences were studied using z-tests.

Results: Grade 5 students perceived significantly lower levels of enjoyment and cognitive processes and a higher level of somatic anxiety in fitness testing classes compared to general PE. Additionally, for Grade 8 students, levels of enjoyment and cognitive processes were significantly lower and somatic anxiety and worry higher in fitness testing classes than in general PE. Furthermore, enjoyment was significantly higher, and cognitive processes, somatic anxiety and worry lower among Grade 5 students compared with Grade 8 students in both contextual PE and during fitness testing class.

Conclusion: Results of this study indicate that students’ perceptions of enjoyment were lower in fitness testing classes compared to PE in general. Additionally, students perceived lower levels of cognitive anxiety and higher levels of somatic anxiety in fitness testing classes than in general PE. It is noteworthy that students might not significantly dislike fitness testing per se but instead have significantly more positive affects towards PE in general. Generally, practitioners conducting fitness testing lessons are encouraged to embrace different strategies such as fostering basic psychological needs or promoting mastery climate to facilitate enjoyment and diminish anxiety.     

Effects of increasing and decreasing physiological arousal on anticipation timing performance during competition and practice

The aim of this study was to investigate if the effects of changes in physiological arousal on timing performance can be accurately predicted by the catastrophe model. Eighteen young adults (8 males, 10 females) volunteered to participate in the study following ethical approval. After familiarisation, coincidence anticipation was measured using the Bassin Anticipation Timer under four incremental exercise conditions: Increasing exercise intensity and low cognitive anxiety, increasing exercise intensity and high cognitive anxiety, decreasing exercise intensity and low cognitive anxiety and decreasing exercise intensity and high cognitive anxiety. Incremental exercise was performed on a treadmill at intensities of 30%, 50%, 70% and 90% heart rate reserve (HRR) respectively. Ratings of cognitive anxiety were taken at each intensity using the Mental Readiness Form 3 (MRF3) followed by performance of coincidence anticipation trials at speeds of 3 and 8 mph. Results indicated significant condition × intensity interactions for absolute error (AE; p = .0001) and MRF cognitive anxiety intensity scores (p = .05). Post hoc analysis indicated that there were no statistically significant differences in AE across exercise intensities in low–cognitive anxiety conditions. In high–cognitive anxiety conditions, timing performance AE was significantly poorer and cognitive anxiety higher at 90% HRR, compared to the other exercise intensities. There was no difference in timing responses at 90% HRR during competitive trials, irrespective of whether exercise intensity was increasing or decreasing. This study suggests that anticipation timing performance is negatively affected when physiological arousal and cognitive anxiety are high.     

Effects of pomegranate extract on blood flow and vessel diameter after high-intensity exercise in young,healthy adults

The effects of pomegranate extract (PE) supplementation were evaluated on high-intensity exercise performance, blood flow, vessel diameter, oxygen saturation (SPO₂), heart rate (HR), and blood pressure (BP). In a randomized, crossover design, nineteen recreationally resistance-trained participants were randomly assigned to PE (1000?mg) or placebo (PL), which were consumed 30?min prior to a repeated sprint ability (RSA) test and repetitions to fatigue (RTF) on bench and leg press. The RSA consisted of ten six-second sprints on a friction-loaded cycle ergometer with 30?s recovery. Brachial artery blood flow and vessel diameter were assessed by ultrasound. Blood flow, vessel diameter, SPO₂, HR, and BP were assessed at baseline, 30?min post ingestion, immediately post exercise (IPost), and 30?min post exercise (30minPost). With PE, blood flow significantly increased IPost RSA (mean difference?=?18.49?mL?min^?1; P?<?.05), and IPost and 30minPost RTF (P?<?.05) according to confidence intervals (CI). Vessel diameter increased significantly 30minPost RSA according to CI and resulted in a significant interaction IPost and 30minPost RTF (P?<?.05). With PE, according to CI, average and peak power output increased significantly in sprint 5 of the RSA (P?<?.05). There was no significant difference between PE and PL for bench (P?=?.25) or leg press (P?=?.15) repetitions. Acute PE supplementation enhanced vessel diameter and blood flow, suggesting possible exercise performance enhancement from increased delivery of substrates and oxygen. The acute timing and capsule form of PE may be advantageous to athletic populations due to ergogenic effects, taste, and convenience.     

American Association for Health,Physical Education,and Recreation

ABSTRACT

Purpose: The purpose of this study was to identify whether post-resistance exercise (REx) blood flow restriction (BFR) can elicit a similar acute training stimulus to that offered by either heavy REx or traditional low-load BFR REx. Method: Ten men completed trials with 30% one-repetition maximum (1RM) for 5 sets of 15 repetitions without BFR (30%), with BFR during exercise (30% RD), and with postexercise BFR (30% RP) and at 75% 1RM for 3 sets of 10 repetitions. Lactate and cortisol were measured before and up to 60 min after exercise. Thigh circumference, ratings of perceived exertion (RPE), and pain were measured before and after exercise. Surface electromyography was measured during exercise. Results: All conditions had a large effect (effect size [ES] > 0.8) on lactate, with the largest effects observed with the 75% condition; no differences were observed between the 30% conditions. All conditions had a moderate effect (ES > 0.25 ≤ 0.4) on increasing thigh circumference. This effect was maintained (ES = 0.35) with the application of BFR after REx (30% RP). Change in RPE, from the first to last set, was significantly greater with 30% RD compared with other conditions (all p < .05). Electromyography amplitude was higher and percentage change was greater for the 75% condition compared with the other conditions (both p < .05). Conclusions: The application of BFR immediately post-REx altered several of the responses associated with REx that is aimed at inducing muscular hypertrophy. Additionally, these changes occurred with less pain and perceived exertion suggesting that this form of REx may offer an alternative, tolerable method of REx.     

Carbohydrate gel ingestion during running in the heat on markers of gastrointestinal distress

The purpose of this study is to measure the effects of carbohydrate ingestion during exercise in the heat by measuring markers of gastrointestinal damage and inflammation. Methods: Active subjects (n?=?7) completed two 60-min running trials in a heated environment (70% VO₂max, 30°C). At minute 20 of exercise, subjects consumed a carbohydrate gel (Cho) (27?g), or a non-carbohydrate placebo (nCho). Plasma endotoxin, I-FABP, TNF-α, IL-6, IL-1β, IL-10, and MCP-1 were measured pre-exercise, 20-min post-exercise, and again 2-h, and 4-h post-exercise. Results: Endotoxin increased 20-min post-exercise compared to pre in the Cho trial only (p?=?.03). I-FABP levels increased 20-min post-exercise in the Cho trial only compared to pre-exercise (p?=?.003). I-FABP levels were also increased in Cho trial 20-min post-exercise when compared to same time point in the nCho trial (p?=?.032). TNF-α increased 20-min post-exercise in the Cho trial only compared to pre (p?=?.03). Plasma IL-6 concentration increased 20-min post-exercise when compared to pre in both the Cho (p?=?.002) and nCho (p?=?.009), but remained elevated at the 2-h time point in the nCho trial (p?=?.03). I-FABP and several plasma cytokines (TNF-α, MCP-1, Il-6) returned to baseline sooner in the Cho trial. Conclusions: Ingestion of carbohydrate gel during exercise in the heat enhances markers of gastrointestinal wall damage.     

Evidence for the Importance of Openness to Experience on Performance of a Fluid Intelligence Task by Physically Active and Inactive Participants

Abstract

The cross-sectional relationship between exercise training history and performance on a fluid intelligence test was examined. In addition, openness to experience was included as a potential trait-based contributor to predicting cognitive performance. Results supported past literature demonstrating that aerobically trained or active participants performed significantly better on the fluid intelligence task than aerobically untrained or inactive participants. Hierarchical regression analysis results revealed, as predicted, that openness to experience was a significant predictor of fluid intellectual performance. When entered into the hierarchical regression equation, openness to experience accounted for 16.0% of unique variance in Culture Fair Intelligence Test performance. By contrast, participants' exercise training history, which initially and significantly (p < . 05) accounted for approximately 12.0% of the variance in cognitive performance, accounted for 5.0% (p > .05) after openness was entered. Participants were, on average, more open than inactive participants. Results are discussed in terms of the possible mechanisms aerobic exercise training and openness to experience share in regard to brain functioning and performance of fluid intelligence tasks. Future research is suggested that examines biological factors known to influence cognitive performance in exercise settings.     

Effects of a Three-Year Exercise Program on Motor Function and Cognitive Processing Speed in Older Women

Abstract

This study evaluated the effects of a three-year exercise program on motor performance and cognitive processing speed of previously sedentary older women, ages 57–85. Variables tested were simple and choice reaction time (CRT), balance, sit and reach flexibility, shoulder flexibility, and grip strength. Subjects participated three times a week in exercise performance classes designed to meet American College of Sports Medicine guidelines. Results indicate that performance was significantly improved on all measures during the course of the study (p < .01) except for the sit and reach test (SRT), where significance was approached (p < .027), but not reached. A comparison of the exercise subjects with a comparable group of nonexercising control subjects revealed significant interactions between treatment and time on all variables except CRT and grip strength. Pretest to posttest scores of the exercise subjects tended to improve over the three-year period, whereas the scores of the control subjects declined. Improved reaction time indicated exercise is effective in reversing or at least slowing certain age-related declines in motor performance and in speed of cognitive processing.     

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.     

Rhythmic Isometric Fatigue Patterns of the Elbow Flexors and Knee Extensors

Abstract

Twenty-seven male subjects performed two 5-min bouts of rhythmic, isometric elbow flexion and two similar bouts of knee extension at a rate of 30 maximal contractions per min. Exponential analyses revealed that the pattern of fatigue for each limb followed a single component curve of the form: Y_t = a₀e ^?Kot + c. An analysis of variance comparing the results from the two limbs revealed that (a) the strength scores for the leg were significantly (p < .05) higher than those for the arm throughout the exercise bouts; (b) both limbs experienced a significant strength decrement; and (c) there was significant interaction between trials and limbs. It appeared that the greater loss of strength by the knee extensors was reponsible for this interaction. It was concluded that during a rhythmic, all-out task, the rates of fatigue experienced by the two muscle groups tend to differ, with the elbow flexors fatiguing more rapidly initially but reaching a plateau at a relatively higher level than the knee extensors.     

Relationship of Social Physique Anxiety to Indicators of Physique

ABSTRACT

Purpose: Maximal heart rate (MHR) is an important physiologic tool for prescribing and monitoring exercise in both clinical and athletic settings. However, prediction equations developed in adults may have limited accuracy in youth. The purpose of this study was to systematically review and analyze the available evidence regarding the validity of commonly used age-based MHR prediction equations among children and adolescents. Methods: Included articles were peer-reviewed, published in English, and compared measured to predicted MHR in male and female participants <18 years old. The standardized mean difference effect size (ES) was used to quantify the accuracy of age-predicted MHR values and a priori moderators were examined to identify potential sources of variability. Results: The cumulative results of 20 effects obtained from seven articles revealed that prediction equations did not accurately estimate MHR (ES= 0.44, p < .05) by 6.3 bpm (bpm). Subgroup analyses indicated that the Fox equation (MHR = 220–age) overestimated MHR by 12.4 bpm (ES = 0.95, p < .05), whereas the Tanaka equation (MHR = 208–0.7*age) underestimated MHR by 2.7 bpm (ES = ?0.34, p < .05). Conclusions: Age-based MHR equations derived from adult populations are not applicable to children. However, if the use of age-based equations cannot be avoided, we recommend using the Tanaka equation, keeping in mind the range of error reported in this study. Future research should control for potential pubertal influences on sympathetic modulation during exercise to facilitate the development of more age-appropriate methods for prescribing exercise intensity.     

Effects of Different Durations of Physical Training on Cardiorespiratory Function,Body Composition,and Serum Lipids

Abstract

The purpose of the study was to determine the effects of 15, 30, and 45 min of conditioning on maximum performance and cardiorespiratory fitness variables, body composition, pulmonary function, and serum lipids. Subjects, ages 20 to 35, were 59 inmates at a California state prison. The conditioning included running and walking and was performed three days/week at approximately 85 to 90% max HR for 20 weeks. The distance covered per exercise session was approximately 1.75, 3.25, and 5.1 miles for the 15-, 30-, and 45-min groups, respectively.

Improvements in treadmill performance time. [Vdot]O₂ max, max O₂ pulse, diastolic blood pressure, and total skinfold fat were proportional to duration of the training session; i.e., the subjects training in the longer duration sessions showed the greater improvements. The control group showed no significant change during the same period. Compared to the control group, the 15-min group made significant reductions in resting HR, total skinfold fat, percent fat, and waist girth and increases in [Vdot]O₂ max, max O₂ pulse,[Vdot]_E max, and treadmill performance time. Vital capacity, FEV_1.0, and % FEV_1.0 remained relatively unchanged in all four groups, as did serum cholesterol and triglycerides. The 45-min group improved significantly more than the 15-min group in treadmill time, [Vdot]O₂ max, max O₂ pulse, resting systolic and diastolic blood pressures, and percent fat. In general, comparisons between the 15- and 30-min groups and between the 30- and 45-min groups failed to yield statistically significant differences.     

Resting Bradycardia,Enhanced Postexercise Heart Rate Recovery and Cardiorespiratory Fitness in Recreational Ballroom Dancers

Purpose: In a cross-sectional study design, we evaluated the resting heart rate (HR_baseline) and exercise and postexercise stress test-related chronotropic responses in male practitioners of recreational ballroom dancing (BD; n = 25, M_age = 26.6 ± 6.1 years) compared to a control group of insufficiently active nondancers (CG; n = 25, M_age = 25.9 ± 4.5 years). Method: All participants underwent a submaximal exercise test. At 85% of the maximal predicted HR, the recovery protocol was started, and heart rate recovery (HRR) was recorded during 1-min intervals for 5 min. Results: Compared with CG, BD showed lower HR_baseline (70 beats per minute [bpm] vs. 62 bpm, respectively, U = 143, p < .05, ES = .46), lower preexercise HR (94 bpm vs. 86 bpm, U = 157, p < .05, ES = .42), longer exercise test duration (346 s vs. 420 s, U = 95.5, p < .05, ES = .59), and higher HRR for 5 min postexercise (U = 1.29–1.89, p < .05, ES = .33–.50) as follows: 1st min (32 bpm vs. 40 bpm), 2nd min (45 bpm vs. 53 bpm), 3rd min (51 bpm vs. 58 bpm), 4th min (55 bpm vs. 59 bpm), and 5th min (59 bpm vs. 63 bpm). The coefficient of HRR from the 1st min to the 5th min postexercise was similar in both groups (U = 229–311, p > .05, ES = < .10–.22). Conclusion: Heightened cardiovascular functional status characterized by favorable enhanced chronotropic dynamics appears to occur in practitioners of recreational ballroom dancing, which suggests that this modality of exercise may result in health benefits.