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1.
Forty-eight volunteer males were randomly assigned to one of three groups. Group I trained with isokinetic exercises, Group II trained with plyometric exercises, and Group III was the control. Subjects in the training groups trained three times per week for 8 weeks. The isokinetic group performed three sets of 10 repetitions per set of leg presses each training session. The plyometric group performed three sets of 10 repetitions per set of depth jumps from a height of 34 inches, with added resistance beginning with weeks 3, 5, and 7 of 10, 15, and 20 pounds, respectively. Prior to and at the end of the training period, all subjects were given a vertical jump-and-reach test. Covariance analysis was used to compare posttest scores with the effect of pretest differences removed. Results showed both training groups improved significantly in vertical jump capacity; however, no significant difference existed between training groups.  相似文献   

2.
Abstract

Three groups of 11 subjects enrolled in required physical education were equated on the basis of bicycling for two minutes at 14 kg. resistance. Group I did weight training, Group II used the Commander Set series of isometric contractions, and Group III participated in normal activities. At the conclusion of the 8-week experimental period all subjects were retested on the bicycle ergometer under the original conditions. Both experimental groups showed statistically significant improvements in the bicycle ergometer test and there were no statistically significant differences between the means of the differences between the initial and final scores of the two experimental groups. It is hypothesized that increases in muscular endurance may be effected by certain programs of isometric contractions as well as by isotonic exercises.  相似文献   

3.
PurposeThe aim of the present study was to determine the association between adherence to the 24-h movement guidelines during middle adolescence and glucose outcomes (glycated hemoglobin and fasting glucose) and type 2 diabetes mellitus (T2DM) in adulthood, 14 and 22 years later.MethodsWe analyzed data from apparently healthy adolescents aged 12–18 years who participated in Waves I and II (1994–1996, n = 14,738), Wave IV (2008–2009, n = 8913), and Wave V (2016–2018, n = 3457) of the National Longitudinal Study of Adolescent to Adult Health (Add Health) in the United States. Physical activity, screen time, and sleep duration were measured using questionnaires, and the 24-h guidelines were defined as: 5 or more times moderate-to-vigorous physical activity per week, ≤2 h per day of screen time, and 9–11 h of sleep for 12–13 years and 8–10 h for 14–17 years. Capillary and venous whole blood was collected and analyzed to determine glycated hemoglobin and fasting glucose for Waves IV and V, respectively.ResultsOnly 2.1% of the adolescents met all the 3 guidelines, and 37.8% met none of them. In both waves IV and V, adolescents who met physical activity and screen time guidelines had lower odds of T2DM in adulthood than those who did not meet any of these guidelines (Wave IV; prevalence ratio (PR) = 0.57, 95% confidence interval (95%CI): 0.21–0.89; Wave V: PR = 0.43, 95%CI: 0.32–0.74). Only for Wave V did adolescents who met all 3 guidelines have lower odds of T2DM at follow-up compared with those who did not meet any of these guidelines (PR = 0.47, 95%CI: 0.24–0.91). Also, for each increase in meeting one of the 24-h recommendations, the odds of T2DM decreased by 18% (PR = 0.82, 95%CI: 0.61–0.99) and 15% (PR = 0.85, 95%CI: 0.65–0.98) in adulthood for Waves IV and V, respectively.ConclusionPromoting all 24-h movement guidelines in adolescence, especially physical activity and screen time, is important for lowering the potential risk of T2DM in adulthood.  相似文献   

4.
Abstract

Levels of physical inactivity and sedentary behaviour among English and Spanish youth are high and vary within different regions of each country. Little though is known about these during specific periods of the day. The purpose of this study was to describe physical activity (PA) and sedentary time during segments of the day and week, and compare these critical contexts between youth in the Liverpool and Madrid areas of England and Spain, respectively. PA was objectively assessed in 235 Liverpool- and 241 Madrid youth (aged 10–14 years) who wore accelerometers for seven consecutive days. Minutes of sedentary time, moderate PA, vigorous PA and moderate-to-vigorous physical activity (MVPA) were calculated for weekdays, weekend days, school time, non-school time and after-school. Between-country differences were analysed using analysis of covariance (ANCOVA). Madrid youth spent significantly more time in sedentary activities than their Liverpool counterparts. Madrid youth engaged in more minutes of moderate intensity physical activity (MPA) than Liverpool youth during weekdays, school time and non-school time (P<0.01). Liverpool children recorded more time in vigorous physical activity (VPA) than Madrid peers during week days and weekend days (P<0.01) and during school time and after-school periods (P <0.01). The MVPA was significantly higher among Madrid youth during non-school time (P<0.01). Around 25% of all youth achieved recommended levels of MVPA. Low levels of MVPA and systematic differences in sedentary time, MPA and VPA exist between Liverpool and Madrid youth. Interventions targeted at the least-active children during weekends, after-school and non-school periods within the cultural contexts common to each city are required.  相似文献   

5.
The present study aimed to describe accelerometer-based physical activity levels in 4- and 5-year-old children (N = 76) on 2 weekdays and 2 weekend days. The children were sedentary for 9.6 hr (85%) daily, while they engaged in moderate to vigorous physical activity (MVPA) for 34 min (5%). Only 7% of the children engaged in MVPA for 60 min per day, and only 26% reached the standard of 120 min of total activity. Their engagement in MVPA did not significantly differ between weekend and weekdays. Mean activity counts and minutes in MVPA did not differ between genders. Physical activity levels in this sample of preschool children were far lower than recommended.  相似文献   

6.
The aim was to assess the relationship between school rhythm and physical activity (PA) in adolescents. The study included 2024 adolescents (12.5–17.4 years). Participants wore an accelerometer for 7 days. A short school rhythm was defined as a short time at school with short recesses and less time in teaching per day (Group 1). A long school rhythm was defined as a longer time at school with more time in teaching and recess (Group 2). Adolescents in Group 1 performed less moderate to vigorous PA (MVPA) than those in Group 2 per week (P < .0001), especially during school days (recess: 3.9 ± 4.0 vs. 9.8 ± 7.9 min · day?1; P < .0001; teaching hours: 14.5 ± 9.8 vs. 19.1 ± 12.0 min · day?1; P < .0001). Adolescents in Group 1 were less likely to meet the PA recommendations than were adolescents in Group 2: 30.7% vs. 34.1% (P < .0001). During school days, the percentage of adolescents who spent more than 2 h · day?1 in sedentary activities was greater in the Group 1 (P < .001). Our results suggest that leisure-time out-of-school hours is used mainly for sedentary activities, and that school time provides a good opportunity for promoting PA.  相似文献   

7.
Abstract

Two studies are presented which deal with the reliability and validity of self-reports of aerobic activity. The first study compared two forms of self-report data obtained as part of a study of intervention strategy. The two forms were daily self-report and weekly retrospective report. Analyses covering the overlapping time period revealed differences in mean minutes engaged in activity, but modest and statistically significant correlations between the two forms among adults participating in the intervention group. No meaningful results were obtained among adults in the control group, nor among children in either group. The need for the development and testing of self-report forms among children was noted, and was the subject of the second study.

In Study II, six different forms on which third to sixth grade children recorded their aerobic activity were compared against two days of continuous observations of their behavior. The six forms varied along two dimensions. The first dimension varied the time period of reporting: half the forms required reporting by segments of the day; the other half allowed for reporting of the day as a whole. The second dimension varied response format: one third of the forms asked for a dichotomous (yes; no) report; one third asked for a trichotomous (no; yes, but less than 20 min; yes, for 20 min or more) report; and one third asked for reporting of precise numbers of minutes. The segmented day forms resulted in significantly higher agreement with the observers' report of activity. This finding is interpreted to be congruent with recent research on the importance of context in the recall of behavior. No effect from parental assistance in child's form completion was detected.  相似文献   

8.
It is commonly believed that a torn ACL or a damaged meniscus may be associated with altered knee joint movements. The purpose of this study was to measure the tibiofemoral kinematics of ACL deficiency with concomitant meniscus deficiency. Unilateral knees of 28 ACL deficient participants were studied while ascending stairs. Among these patients, 6 had isolated ACL injuries (group I), 8 had combined ACL and medial meniscus injuries (group II), 8 had combined ACL and lateral meniscus injuries (group III) and 6 had combined ACL and medial-lateral meniscus injuries (group IV). Both knees were then scanned during a stair climb activity using single fluoroscopic image system. Knee kinematics were measured at 0°, 5°, 10°, 15°, 30° and 60° of flexion during ascending stairs. At 0°, 15° and 30° flexion of the knee, the tibia rotated externally by 13.9 ± 6.1°,13.8 ± 9.5° and 15.9 ± 9.8° in Group I. Group II and III exhibited decreased external rotation from 60° to full extension. Statistical differences were found in 0°, 15°and 30° of flexion for the 2 groups compared with Group I. In general, the tibia showed anterior translation with respect to the femur during ascending stairs. It was further determined that Group III had larger anterior translation compared with Group IV at 0° and 5° of flexion (?6.9 ± 1.7 mm vs. 6.2 ± 11.3 mm, P = 0.041; ?9.0 ± 1.8 mm vs. 8.1 ± 13.4 mm, P = 0.044). During ascending stairs the ACL deficient knee with different deficiencies in the meniscus will show significantly different kinematics compared with that of uninjured contralateral knee. Considering the varying effect of meniscus injuries on knee joint kinematics, future studies should concentrate on specific treatment of patients with combined ACL and meniscus injuries to protect the joint from abnormal kinematics and subsequent postoperative degeneration.  相似文献   

9.
Background:This study examined the volume and patterns of physical activity(PA) and sedentary time(ST) across different segments of the week among boys and girls.Methods:A total of 188 children aged 7-12 years wore a wrist-mounted ActiGraph GT3 X+accelerometer for 7 days.Time spent in PA and ST was calculated using ActiLife software.The mean number of minutes of light PA,moderate PA,vigorous PA,moderate-to-vigorous PA(MVPA),and ST were calculated per weekday(before school,during school,and after school) and per weekend day(morning and afternoon-evening).Results:After school represented the greatest accumulation of ST compared with before school and during school segments.Boys engaged in225.4 min/day of ST(95% confidence interval(CI):216-235),and girls engaged in 222.2 min/day of ST(95%CI:213-231).During school,boys engaged in significantly more MVPA than girls(46.1 min/day(95%CI:44-48) vs.40.7 min/day(95%CI:39-43)).Across the whole weekday,boys participated in significantly more MVPA than girls(103.9 min/day(95%CI:99-109) vs.95.7 min/day(95%CI:90-101)).The weekend afternoon—evening segment represented the larger accumulation of ST,where boys were significantly more sedentary than girls(367.5 min/day(95%CI:353-382) vs.339.8 min/day(95%CI:325-355),respectively).Conclusion:Our findings suggest that children are highly sedentary and spend little of their time in school in MVPA,especially girls.Routine breaks in school elicit increases in light PA and MVPA.Future work should consider the use of more active breaks within school time to encourage PA and reduce ST.  相似文献   

10.
Abstract

Walking is the most natural physical activity to maintain and improve fitness and health. Walking downhill is usefully adopted to plan training programmes to improve the strength, particularly in older adults. The present research was aimed to evaluate the influence of downhill walking on leg strength in young adult. A total of 32 females (age 26 ± 4 years; height 1.64 ± 0.05 m; body mass 57.6 ± 5.6 kg) were divided into four groups and they carried out an exercise intervention consisting of three sessions per week for 6 weeks, each lasting 30 minutes. Groups were defined at several workloads characterised by treadmill inclination (%) and walking speed (m·s?1): Level Walking at treadmill inclination 0% and walking speed 1.0; Uphill Walking at +20%, 0.75; Downhill Walking (DW) at ?20%, 1.36; and Mixed Walking at +20%, 0.75 and ?20%, 1.36 each lasting 15 minutes. Maximum voluntary contraction (MVC) developed by the Quadriceps Femoris and Endurance Time at 60% MVC were evaluated before and after experimental period. At the end of each session, Borg's scale and Visual Analogue Scale (VAS) were adopted in order to evaluate perception of rate exertion and pain. Statistical analysis showed significant only in MVC for DW in both right and left legs. Borg's scale and VAS described light activity free of pain. Present findings showed how an eccentric exercise, short lasting and at a low workload, can be useful in inducing improvements in leg strength.  相似文献   

11.
The aim of the current study was to establish which indicators of mobility are associated with successful wheelchair rugby performance and determine whether these indicators differed across classification. Data were collected from 11 international teams during 30 matches (353 match observations) using a radio-frequency-based, indoor tracking system across two tournaments. Players (n = 111) were first grouped by team rank as determined by their International Wheelchair Rugby Federation (IWRF) world ranking (LOW, MID, HIGH) and then into one of four groups based on their IWRF classification: Group I (0.5), Group II (1.0–1.5), Group III (2.0–2.5) and Group IV (3.0–3.5). The volume of activity (relative distance and mean speed), peak speed and time spent within classification-specific arbitrary speed zones were calculated for each individual. Although no differences were identified in the volume of activity, playing time was significantly reduced in LOW (34:51 ± 8:35) compared to MID (48:54 ± 0:51) and HIGH (45:38 ± 9:53), which was further supported by the greater number of substitutions performed by LOW. HIGH achieved greater peak speeds (3.55 ± 0.40 m · sˉ1) than LOW (3.27 ± 0.42 m · sˉ1) and MID (3.45 ± 0.41 m · sˉ1). Peak speed was further shown to be classification-dependent (P ≤ 0.005), whereby HIGH Groups III and IV players achieved greater peak speeds than LOW and MID. The time spent performing high-intensity activities was also greater in HIGH compared to LOW and MID, whilst further influenced by classification (P ≤ 0.0005). To conclude, peak speed and the ability to perform a greater number of high-intensity activities were associated with successful performance in wheelchair rugby.  相似文献   

12.
目的:通过测试萎缩骨骼肌细胞Caspase-3、SOD活性和MDA含量,观察补充扇贝肽对运动大鼠停训导致骨骼肌萎缩后肌细胞Caspase-3活性及其抗氧化能力的影响,研究扇贝肽对停训后骨骼肌萎缩的干预作用。方法:40只SD雄性大鼠以15 m/min的速度,持续性水平跑台训练30 min开始进行递增负荷运动,运动6 d/周,休息1 d/周,速度递增3 m/min/周,时间递增30 min/周,运动3周后即刻处死10只大鼠为基础对照组,其余大鼠随机分组为补充安慰剂阴性对照组、补充牛乳阳性对照组和补充扇贝肽实验组,30只大鼠左侧后肢实施石膏固定模拟停训模型,并进行扇贝肽补充实验。实验组和对照组所有动物每天分别进行灌胃15%扇贝肽饮料2mL、等量的安慰剂和牛乳。结果:发现补充扇贝肽可显著减低停训后萎缩骨骼肌细胞MDA含量增加,增加SOD活性,提高细胞内抗氧化能力,可显著抑制停训后萎缩骨骼肌细胞Caspase-3的活性,从而抑制骨骼肌收缩蛋白和结构蛋白的降解,促进萎缩骨骼肌的恢复。  相似文献   

13.
Abstracts     
This study investigated the changes in urinary neopterin, a biochemical marker of cellular immune activity, in elite male rowers undertaking a progressive increase in training prior to Olympic competition. Twenty‐seven male rowers of the 1992 Great Britain team provided daily urine samples for a 4‐week period of training that included 17 days of altitude training and 10 days of heat acclimatization. The mean (± s.d.) ratio of neopterin/ creatinine in urine increased from pre‐training values of 135 ± 32 to a peak of 219± 121 μmol neopterin per mol creatinine on day 19 of training (P < 0.05). Changes in the ratio of neopterin/creatinine with training were found to be transient and highly variable between subjects, ranging from no change to peak values five‐fold greater than baseline. On the basis of the in vivo measurement of cell‐mediated immunity employed in this study, we conclude that elite athletes engaged in high‐intensity training prior to competition show either no change or a moderate increase in cellular immune activation.  相似文献   

14.
Abstract

The purpose of this study was to determine the effects of a 15-week aerobic activity program on the total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) levels of 25 high school students, ages 14–17 years (experimental group = 14, control group = 11). Participants in the activity program exercised 4 days per week in a specially designed physical education class, while the control group participated in the regular physical education program. Results of the analysis of covariance found significant reductions in TC in the training group (control group Adj M = 190.2 mg/dl, experimental group Adj M = 173.1 mg/dl, p > .05), but no significant changes in HDL-C (control group Adj M = 49.8 mg/dl, experimental group Adj M = 50 mg/dl). While the exercise program appeared to have a beneficial effect on TC in 12 of 14 participants (86%), HDL-C also dropped in 12 of 14 participants (86%).  相似文献   

15.
In order to determine the influence of two artificially induced alkalotic states on the ability to perform maximal exercise, six male subjects (mean age, 22.0 years; mean height, 176.8 cm; mean weight, 69.1 kg; mean VO2 max, 3.83 l min-1) were studied during three experimental trials. The subjects performed six 60-s cycling bouts, at a work rate corresponding to 125% VO2 max, with 60 s recovery between work bouts; these regimens were performed 1 h after the ingestion of a solution containing either; I, placebo; II, NaHCO3 in a dosage of 0.15 g per kg body weight; or III, NaHCO3 0.30 g per kg body weight. The sixth work bout was continued until the pedal velocity dropped below 50 rev min-1. Total work done for the entire work period was calculated. Blood samples were taken from a forearm vein prior to the exercise bouts for analysis of pH and HCO3. The results showed a significant pre-exercise difference in pH and HCO3 for all conditions (P less than 0.01). In conditions where artificial alkalosis had been achieved prior to exercise there was significant increase in the work produced: I, 121.6 kJ; II, 133.1 kJ; III, 133.5 kJ (P less than 0.05). The time to fatigue in the six bout was also significantly increased; I, 74.7 s; II, 111.0 s; III, 106.0 p (P less than 0.05). There were no significant differences between conditions II and III. Thus augmentation of the bicarbonate reserves has a significant positive effect on the energy metabolism in interval-type exercise, leading to an increase in the work done and in the time to fatigue.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
Abstract

This study was made to determine a current set of concepts which physical educators believe should characterize the purposes of the modern college program of general physical education. A review of current literature was conducted to identify and define those concepts which seemed to be characteristic of the purposes of the general college program of physical education. From this literature a structured interview guide was developed. Sections I and II of this guide contained questions concerning the current status of this program. Questions designed to elicit opinions with regard to selected aspects of the general college program of physical education also were included. Section III contained statements of concepts currently appearing in the literature of higher education. The data were obtained by the personal interview and the mailed questionnaire technique. The Kolmogorov-Smirnov test was employed to compare responses among three groups of respondents: a group of physical educators who were selected on the basis of their specific qualifications with regard to the general college program (Group I), a jury of physical educators who were considered expert in the overall field of physical education (Group II), and a group composed of deans of instruction (Group III). This test was designed to determine whethere were statistically significant differences of opinion among responses of the three groups. The data were reported and interpretations and analyses of the data were made. It was found that physical educators and academic deans of instruction were in close agreement in most instances with regard to beliefs concerning the general college program of physical education.  相似文献   

17.
Abstract

The objective of this study was to determine the effect of a marathon run on serum lipid and lipoprotein concentrations and serum muscle enzyme activities and follow their recovery after the run. These blood concentrations were measured before, immediately after, and serially after a marathon run in 15 male recreational runners. The triglyceride level was significantly elevated postrace, then fell 30% below baseline 1 day after the run, and returned to baseline after 1 week. Total cholesterol responded less dramatically but with a similar pattern. High-density lipoprotein cholesterol remained significantly elevated and low-density lipoprotein cholesterol was transiently reduced for 3 days after the run. The total cholesterol/high-density cholesterol ratio was significantly lowered for 3 days. Serum lactate dehydrogenase activity significantly doubled postrace and then declined but remained elevated for 2 weeks. Serum creatine kinase activity peaked 24 hr after the run, with a 15-fold rise, and returned to baseline after 1 week. The rise of these enzymes reflects mechanically damaged muscle cells leaking contents into the interstitial fluid. It is concluded that a prolonged strenuous exercise bout in recreational runners, such as a marathon, produces beneficial changes in lipid blood profiles that are significant for only 3 days. However, muscle damage is also evident for 1 week or more from the dramatic and longlasting effect on enzyme levels. Laboratory values for these runners were outside normal ranges for some days after the race.  相似文献   

18.
BackgroundThis study systematically synthesized and quantified the relationship linking state laws governing school physical education (PE) to PE attendance and physical activity (PA) in class and throughout the day and week among students in the USA.MethodsA keyword search was performed in PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Academic Search Complete, and EconLit. Meta-analyses were performed to estimate the effects of state PE laws.ResultsA total of 17 studies were included in the review, and five contributed to the meta-analyses. A total of 8 studies used nationally representative school- or student-level data, three focused on multiple states, and the remaining six examined the PE laws of a single state. The presence and strength of state PE laws were positively associated with PE attendance and the frequency and duration of PA during PE classes and throughout the school day. Compared to those residing in states with weak or no PE laws, students in states with strong PE laws had an additional 0.2 days (95% confidence interval (95%CI): 0.1–0.4) of PE attendance per week and spent an additional 33.9 min (95%CI: 22.7–45.0) participating PE classes per week. State PE laws affected girls’ PA more than boys’. Different aspects of state PE laws tended to affect students’ PE attendance differently. Disparities in the implementation of state PE laws existed across schools.ConclusionFuture studies should adopt objective measures on PE and PA participation and examine the roles schools and districts play in mediating the effect of state PE laws on students’ PE attendance and PA.  相似文献   

19.
Abstract

The purpose of this study was to establish whether an accumulated brisk walking programme, performed during the school day, is effective in changing body composition in primary school children aged 5–11 years. Altogether, 152 participants (79 boys and 73 girls) took part in this repeated-measures intervention study, divided into groups of walkers and controls. The walkers took part in the intervention during school time, which involved brisk walking around the school grounds for 15 min in the morning and afternoon, at least three times a week for 15 weeks. This represented an additional 90 min of moderate physical activity per week. The controls undertook their usual school day activities. Pre- and post-intervention anthropometric and body composition measures were taken. Body fat (?1.95 ± 2.6%) and fat mass (?0.49 ± 1.0 kg) were significantly reduced in the walkers after the intervention, whereas the controls showed no significant changes in these measures. Our results show that regular accumulated bouts of brisk walking during the school day can positively affect body composition in primary school children.  相似文献   

20.
Abstract

Two matched groups of 10 subjects each were employed to assess possible central facilitation effects over 4 weeks of training. Each of the 12 training sessions consisted of 20 trials of maximum isometric wrist flexion for 5 sec. with a 30-sec. rest period between trials. Two experimental conditions were used. On alternate sessions condition one consisted of 20 trials with odd-numbered trials being unilateral and even-numbered trials being simultaneous bilateral efforts. Condition two consisted of the first 15 trials being unilateral and the last 5 trials simultaneous bilateral. The right limb in Group I and the left limb in Group II constituted the criterion measures. Central facilitation effects due to simultaneous bilateral isometric wrist contractions were: (a) not present initially and (b) not elicited through the 4 weeks of training. The finding held for both dominant and nondominant limbs and for fatigued and nonfatigued states.  相似文献   

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