Effectiveness of Rest,Abdominal Cold Packs,and Cold Showers in Relieving Fatigue

Abstract

The purpose of this study was to compare three methods of relieving fatigue between bouts of strenuous exercise—rest, abdominal cold packs, and cold showers. Fifteen subjects were used in the study; each subject participated in each of the three treatments, making a total of 45 measurements. The subjects ran on a treadmill which was set at 8 mph with a 10 percent elevation, until their pulse rates reached 180 beats per minute. One of the three treatments was then applied for 10 min., after which the subjects engaged in a second treadmill run until heart rates reached 180 beats per minute. The time of the second treadmill run was the main criterion measure.

A complete randomized block design was used to test the differences among the three treatments for statistical significance. The Newman-Keuls sequential range test was employed to test differences between all possible pairs of treatment. Abdominal cold packs proved to be the most effective treatment, with the cold shower second and rest third.     

Heart Rates of Selected Male College Freshmen during a Season of Basketball

Abstract

Seven basketball athletes were studied to determine the effect of a season of competition on the heart. Pre- and postseason variables of resting and recovery heart rates plus the minutes of treadmill performance to produce a peak of 180 heart beats per minute were studied via an ECG telemetering transmitter. Variation of the resting heart rate between the preseason and postseason trials was not statistically significant; a significant reduction in the postseason treadmill performance task was obtained and a more rapid postseason recovery of the heart rate was observed.     

大负荷运动状态下男运动员部分生理、心理指标测试分析

采用台阶实验法，测试大负荷运动状态下男运动员的心率、肺活量、闪烁频率、平衡能力等生理、心理指标。结果表明：40cm高、每min上下40次台阶实验中，被试心率均可达180bs／min以上，该实验可作为研究大负荷运动状态下测试生理、心理机能的方法；在大负荷运动状态下，运动后即刻心理机能提高；运动后即刻与休息5min后的心理指标比较显示，心理机能可能存在延迟下降的现象。     

Comparison of different theoretical models estimating peak power output and maximal oxygen uptake in trained and elite triathletes and endurance cyclists in the velodrome

Abstract

The primary objective of this study was to examine the relationship between heart rate intensity and pedometer step counts in adolescents. To determine cardiorespiratory fitness, 106 participants (47 boys, 59 girls, mean age 14.2 years, s = 0.8) completed the Queen's College Step Test and were classified as having low, moderate or high cardiorespiratory fitness. Adolescents also completed a 10-min treadmill trial while wearing a pedometer and heart rate monitor. The participants were instructed to maintain their heart rate between 65 and 75% of their maximum heart rate while running or walking on a treadmill. A heart rate of 65–75% maximum was associated with 146 steps per minute (s = 22) in boys and 137 steps per minute (s = 22) in girls. Results of analysis of variance indicated that there was a main effect for level of fitness (F _2,102 = 9.36, P < 0.001). The correlation between mean steps per minute and estimated maximum oxygen consumption was statistically significant (r = 0.44, P < 0.001). The results from this study suggest that a step rate of 130 steps per minute is equal to 65–75% maximum heart rate in low-fit adolescents and achieving 130 steps per minute could be used as an initial goal to improve fitness.     

Indoor 16.1-km time-trial performance in cyclists aged 25- 63 years

In this study, we assessed age-related changes in indoor 16.1-km cycling time-trial performance in 40 competitive male cyclists aged 25-63 years. Participants completed two tests: (1) a maximal ramped Kingcycle ergometer test, with maximal ramped minute power (RMPmax, W) recorded as the highest mean external power during any 60 s and maximal heart rate (HRmax, beats min(-1)) as the highest value during the test; and (2) an indoor Kingcycle 16.1-km time-trial with mean external power output (W), heart rate (beats min(-1)), and pedal cadence (rev min(-1)) recorded throughout the event. Results revealed age-related declines (P < 0.05) in absolute and relative time-trial external power output [(24 W (7.0%) per decade], heart rate [7 beats min(-1) (3.87%) per decade], and cadence [3 rev min(-1) (3.1%) per decade]. No relationships (P > 0.05) were observed for mean power output and heart rate recorded during the time-trial versus age when expressed relative to maximal ramped minute power and maximal heart rate respectively. Strong relationships (P < 0.05) were observed for maximal ramped minute power and time-trial power (r= 0.95) and for maximal heart rate and time-trial heart rate (r= 0.95). Our results show that indoor 16.1-km time-trial performance declines with age but relative exercise intensity (%RMPmax and %HRmax) does not change.     

85 Years Later,RQES Remains Young,Energized, Innovative,and Strong!

Abstract

Subject performed a five-choice reaction time (RT) and movement time (MT) task while walking on a treadmill at heart rates (HR) of approximately 80 (standing still), 115, 145 and 175 beats per minute (bpm). Five-choice RT was optimal at a HR of 115 bpm and worst at 175 bpm, thereby supporting the hypothesis of an inverted U relationship between activation and choice RT. On the other hand, MT improved linearly with increased levels of HR, showing that these two parameters are affected quite differently by concomitant physical exertion.     

小学生50米×8往返跑心率变化规律研究

为确定小学生耐力锻炼安全有效的负荷强度,采用试验法、数理统计法,以50米×8往返跑过程中男女学生心率强度和变化规律为研究内容,抽取厦门市金尚小学五年级72名为观察对象,采用ON-rhythm 410 progress心率表,按照50米×8往返跑测试成绩合格、良好、优秀三个等级进行分组测试,结果显示;学生往返跑第三次时平均心率已经达到181次/分。心率在190~200次/分的强度下要持续1分30秒左右。研究认为小学生50米×8往返跑的练习应循序渐进的原则,最高心率维持时间不宜超过1分30秒的时间范围。     

散打运动员体能训练课的特点及结构探讨

文章结合当前散打运动员体能训练的实际,从训练学和运动医学角度探讨了散打运动员体能训练课的性质,生理基础,体能训练课的结构。指出散打运动员的体能训练中应尽可能地把主要生理负荷强度维持在心率160￣170次/min的范围内,并适宜地进入心率180次/min负荷强度的大运动量课,适当安排极限训练强度的训练;训练课的生理负担量应根据人体生理功能活动变化的规律逐渐加大;训练结束前要逐渐减少运动量,并进行必要的调整活动,有利于超量恢复的进行。     

Effects of Various Periods of Inactivity on Retention of Newly Acquired Levels of Muscular Endurance

Abstract

Male university students (N = 54) engaged in an 8-week training program with sessions held three times per week. Each session consisted of one “all-out” bout of right elbow flexion on an arm lever ergometer against a resistance of 11.03 lbs. at a work rate of 40 repetitions per minute. Following the training phase of the study, the subjects were randomly assigned to three experimental groups and ceased training for either 8, 10, or 12 weeks. At the conclusion of the inactivity period, each subject retrained until his peak performance of the training program had been equaled or exceeded. The analysis of data revealed that no difference existed among the groups: (a) at the beginning of the training program, (b) at the termination of the training program, (c) following the various inactivity periods, and (d) in the number of sessions needed to retrain to the peak performance attained during the training period. The within-group analysis indicated that each group had experienced: (a) significant muscular endurance development during the training period, (b) significant loss of endurance during the period of inactivity, and (c) significant retention of the newly acquired endurance over the inactivity period. Peak performance during the retraining phase was achieved in approximately one-fourth the number of training sessions initially required to attain the same level during the developmental phase.     

Heart rate responses of male orienteers aged 21-67 years during competition

Abstract

Orienteering is a sport in which it is common for most participants to be aged over 40 years, but research into the demands of the sport has focused almost exclusively on elite participants aged 21–35 years. The aim of the present study was to examine the heart rate responses of older male orienteers. Thirty-nine competitive male orienteers were divided into three groups: group 1 (international competitive standard, n=11, age 21–67 years), group 2 (national competitive standard, n=15, age 24–66 years) and group 3 (club competitive standard, n=13, age 23–60 years). Each participant had his heart rate monitored during two orienteering races of contrasting technical difficulty. The results were analysed using analysis of covariance, with age as a covariate, and Pearson product-moment correlation coefficients to determine whether age was related to the observed heart rate responses. The groups did not differ in their peak (175±12 beats · min^?1, P=0.643) or mean (159±13 beats · min^?1, P=0.171) heart rates during the races. There was a decline of 6 beats · min^?1 · decade^?1 (P=0.001) for peak heart rate and 5 beats · min ^?1·decade^?1 (P<0.001) for mean heart rate. Mean heart rates were 86±6% of the participants' maximal heart rates and were not associated with age. The orienteers in group 1 displayed a lower (P<0.005) within-race standard deviation in heart rate (6±2 beats · min^?1) than those in groups 2 and 3 (10±3 and 10±4 beats · min^?1, respectively). In conclusion, the mean heart rates indicated that all three groups of orienteers ran at a relative high intensity and the international competitive standard orienteers displayed a less variable heart rate, which may have been related to fewer instances of slowing down to relocate and being able to navigate while running at relatively high speeds.     

Upper and lower body responses to repeated cyclical sprints

Purpose: To compare the physiological and perceptual responses of the upper and lower body to all-out cyclical sprints with short or long rest periods between sprints.

Methods: Ten recreationally trained males completed four 10?×?10?s sprint protocols in a randomized order: upper body with 30?s and 180?s of rest between sprints, and lower body with 30?s and 180?s of rest between sprints. Additionally, maximum voluntary contractions (MVC) were measured at pre-sprint and post-sprints 5 and 10. Normalized (% of first sprint) peak power, MVC, heart rate (HR) and rating of perceived exertion (RPE) were compared between upper and lower body within the same recovery period, and absolute values (Watts, bpm, RPE scores) were compared within the same body part and between recovery periods.

Results: Trivial differences were identified in normalized peak power, HR and RPE values between the upper and lower body in both recovery conditions (<2%, d?≤?0.1), but MVC forces were better maintained with the upper body (～9.5%, d?=?1.0) in both recovery conditions. Absolute peak power was lower (～147?Watts, d?=?1.3), and HR was higher (～10?bpm, d?=?0.73) in the 30?s compared to 180?s condition in both the upper and lower body whereas RPE scores were similar (<0.6?RPE units, d?≤?0.1). Despite the reductions in peak power, MVC forces were better maintained in the 30?s condition in both upper (2.5?kg, d?=?0.4) and lower (7.5?kg, d?=?0.7) body.

Conclusions: Completing a commonly used repeated sprint protocol with the upper and lower body results in comparable normalized physiological and perceptual responses.     

Circulatory effects of fluid loss and fluid intake during exercise

Abstract

Cardiorespiratory responses to two levels of exercise (133 and 200 W) on a bicycle ergometer were measured in nine subjects before and after a 1‐h outdoor run of 12.8 km completed in ambient temperatures of 20–25° C. After the run, the subjects showed a mean weight loss of 1.49 kg; the laboratory exercises produced higher mean levels of O2 consumption than before the run (1.91 and 2.66 1 min‐1 compared with 1.80 and 2.46 1 min‐1) and higher mean heart rates (141 and 158 beats min‐1 compared with 115 and 140 beats min‐1); and lower levels of stroke volume (83 and 85 ml compared with 109 and 101 ml) and of cardiac output (11.6 and 13.3 1 min‐1 compared with 12.6 and 14.1 1 min‐1). Five subjects were studied in a similar way on a second occasion when they consumed 1.25 1 of a dextrose‐electrolyte solution during the first 45 min of the outdoor run. Differences in the exercise variables measured before and after the outdoor run were now small or insignificant. It is postulated that in the first study uncompensated loss of body water reduced plasma volume and cardiac filling, thus reducing stroke volume and cardiac output. Such changes jeopardize body temperature regulation during exercise.     

Relationship between laboratory-measured variables and heart rate during an ultra-endurance triathlon

The aim of the present study was to examine the relationship between the performance heart rate during an ultra-endurance triathlon and the heart rate corresponding to several demarcation points measured during laboratory-based progressive cycle ergometry and treadmill running. Less than one month before an ultra-endurance triathlon, 21 well-trained ultra-endurance triathletes (mean +/- s: age 35 +/- 6 years, height 1.77 +/- 0.05 m, mass 74.0 +/- 6.9 kg, = 4.75 +/- 0.42 l x min(-1)) performed progressive exercise tests of cycle ergometry and treadmill running for the determination of peak oxygen uptake (VO2peak), heart rate corresponding to the first and second ventilatory thresholds, as well as the heart rate deflection point. Portable telemetry units recorded heart rate at 60 s increments throughout the ultra-endurance triathlon. Heart rate during the cycle and run phases of the ultra-endurance triathlon (148 +/- 9 and 143 +/- 13 beats x min(-1) respectively) were significantly (P < 0.05) less than the second ventilatory thresholds (160 +/- 13 and 165 +/- 14 beats x min(-1) respectively) and heart rate deflection points (170 +/- 13 and 179 +/- 9 beats x min(-1) respectively). However, mean heart rate during the cycle and run phases of the ultra-endurance triathlon were significantly related to (r = 0.76 and 0.66; P < 0.01), and not significantly different from, the first ventilatory thresholds (146 +/- 12 and 148 +/- 15 beats x min(-1) respectively). Furthermore, the difference between heart rate during the cycle phase of the ultra-endurance triathlon and heart rate at the first ventilatory threshold was related to marathon run time (r = 0.61; P < 0.01) and overall ultra-endurance triathlon time (r = 0.45; P < 0.05). The results suggest that triathletes perform the cycle and run phases of the ultra-endurance triathlon at an exercise intensity near their first ventilatory threshold.     

Comparison of Recovery Procedures for the Reduction of Exercise Stress

Abstract

This study investigated the effects of three types of recovery procedure on (a) circulatory recovery from a standardized bicycle ergometer exercise, (b) performance in a second standardized bicycle ergometer exercise, and (c) circulatory recovery from the second exercise. The recovery procedures were complete rest, light activity, and cold showers. Each of 10 male subjects underwent each recovery procedure on separate days. Analysis of variance for a randomized complete blocks design was used in the analysis of the data. Results indicated that cold showers decreased recovery heart rate after the first standardized exercise from 115 to 96 beats/minute and after the second exercise from 164 to 152 beats/ minute when compared with the other two conditions. Speed of performance in the second exercise was improved from 40.4 and 40.3 sec. in the case of rest and light activity to 38.9 sec. for cold showers. These improvements were all statistically significant at the .05 level. Three physiological explanations, not necessarily independent, are advanced: (a) local vasoconstriction of the skin vessels and vasodilatation of the muscle vessels causing a greater proportion of total blood flow to the working muscles, (b) establishment of a greater thermal gradient between the core and shell of the body allowing heat movement to the surface of the body by conduction between tissues rather than by skin blood flow, and (c) a decrease in sweat rate, thereby suppressing release of bradykinin, a vasodilator substance.     

剧烈运动对几种血清酶活性和T 细胞的影响

通过对大学生剧烈运动时血清酶活性和剧烈运动及中等强度运动时外周血中Ｔ细胞总数变化的观察,发现：剧烈运动后血清磷酸肌酸激酶、磷酸肌酸同工酶、乳酸脱氢酶、α－羟丁酸脱氢酶的活性均显著升高,３ｈ后恢复。外周血中Ｔ细胞总数百分率剧烈运动后２ｈ显著下降,１２ｈ后基本恢复。中等强度运动后则无明显变化。结果提示：剧烈运动可导致骨骼肌和心肌细胞的损伤及细胞免疫功能下降。由此说明健身运动的最大心率不宜超过１８０～１９５次／ｍｉｎ。     

Cardiorespiratory Adaptations to Training at Specified Intensities

Abstract

Sixteen college men were randomly divided into three training groups and one control group in a study of selected cardiorespiratory adaptations to six weeks of training exercises eliciting either 120, 150, or 180 heart rates. Training consisted of walking on the motor driven treadmill for 10 min. a day, 3 days per week. Highly significant differences were found in the analysis of pre-post Balke treadmill test scores. The Åstrand-Ryhming nomogram prediction of aerobic capacity also showed highly significant changes due to training. Analysis of group differences revealed that the 180 training group's improvement was significantly different from all other groups in both tests. The 150 group was found to be significantly different from the 120 and control groups in the Balke test analysis. No changes were noted in resting pulse rate nor in the pulse rate—oxygen consumption relationship. However, there were small positive differences in the grade required to elicit the training heart rates. The study supports the hypothesis that intense activity is necessary to bring about the changes associated with cardiorespiratory endurance.     

Cardiovascular Fitness and Maximal Heart Rate Differences among Three Ethnic Groups

Abstract

The current study examines maximal heart rate and maximal treadmill time differences among three ethnic groups. In 1985, 1,047 city employees (572 male, 475 female) participated in a comprehensive health promotion program. Data were collected from a self-administered health and lifestyle questionnaire, maximal treadmill exercise stress test, and other clinical measures. The participants were divided into white male (n = 368), black male (n = 159), Mexican-American male (n = 45), white female (n = 256), black female (n = 189), and Mexican-American female (n = 30) subgroups based on self-reported ethnic identity. Univariate analyses revealed no significant differences in age-adjusted maximal heart rate or maximal treadmill time for males. Mean age-adjusted treadmill time for black females (478.0 ± 228.2 s) was significantly lower than for white (652.5 ± 227.7 s) and Mexican-American (594.5 ± 226.7 s) females (p <. 05). Mean age-adjusted maximal heart rate for black females (174.4 ± 12.4 beats/min) was significantly lower than for white (179.3 ± 13.4 beats/min) and Mexican-American (182.0 ± 13.5 beats/min) females (p < .05). Following adjustment for cardiovascular fitness level, that is, treadmill time, as well as age, these differences were no longer apparent. We concluded that the comparatively low maximal heart rate of black females may be partially explained by a significantly lower cardiovascular fitness level relative to white and Mexican-American females.     

Relative Strenuousness of Selected Sports as Performed by Women

Abstract

Women participants in archery, badminton, basketball, bowling, golf, hockey, Softball, tennis, and volleyball were tested to determine the relative strenuousness of these sports. The subjects' heart beats were telemetered during participation in each sport, and estimates of their ventilation and oxygen uptake for each activity were determined from data collected in the laboratory.

Mean heart rates, oxygen uptake and VO₂ per kilogram of body weight were calculated for each subject in each sport. Comparisons were made to determine which activities demanded the greatest energy expenditure.

Heart rates ranging from a mean of 85 beats/min. in bowling to a mean of 185 beats/min. for the roving player in basketball were recorded. The energy expenditure of the roving player in basketball was similar to that of the center halfback in hockey; these two positions required a significantly greater O₂ uptake than the positions tested in all other sports. Play in these positions was classified as heavy activity.

The non-roving positions of forward and guard in basketball, badminton, tennis, Softball (pitcher), and volleyball were rated as moderate activity. Golf, archery, and bowling were categorized as light activity in terms of energy expenditure.     

Power output of field-based downhill mountain biking

Abstract

The purpose of this study was to assess the power output of field-based downhill mountain biking. Seventeen trained male downhill cyclists (age 27.1 ± 5.1 years) competing nationally performed two timed runs of a measured downhill course. An SRM powermeter was used to simultaneously record power, cadence, and speed. Values were sampled at 1-s intervals. Heart rates were recorded at 5-s intervals using a Polar S710 heart rate monitor. Peak and mean power output were 834 ± 129 W and 75 ± 26 W respectively. Mean power accounted for only 9% of peak values. Paradoxically, mean heart rate was 168 ± 9 beats · min^?1 (89% of age-predicted maximum heart rate). Mean cadence (27 ± 5 rev · min^?1) was significantly related to speed (r = 0.51; P < 0.01). Analysis revealed an average of 38 pedal actions per run, with average pedalling periods of 5 s. Power and cadence were not significantly related to run time or any other variable. Our results support the intermittent nature of downhill mountain biking. The poor relationships between power and run time and between cadence and run time suggest they are not essential pre-requisites to downhill mountain biking performance and indicate the importance of riding dynamics to overall performance.