Residual effect of graded levels of exercise on metabolic rate

The hypothesis that exercise induces a residual effect on metabolic rate only when the intensity exceeds a certain threshold was tested by studying 10 healthy, untrained adults performing graded levels of bicycle ergometry on five separate occasions. The exercise consisted of four 30-min periods at intensities ranging from 0 to 100 Watts. Energy expenditure was measured by continuous indirect whole-body calorimetry. The highest level of exercise increased 24-h energy expenditure by 34 per cent. Food intake was modified for each measurement in order to maintain energy balance. Sleeping and basal metabolic rates on the night following exercise were raised even at low intensities of exercise. There was an almost linear dose-response relationship and no evidence of a threshold. However, the effect was small, amounting to only 5.8 per cent overnight and 3.9 per cent in the morning following 2 h exercise at over 60 per cent VO2 max during the preceding day. This suggests that the residual energy expenditure incurred after moderate levels of exercise is unlikely to be a very useful adjunct to slimming regimes.     

The effects of aerobic fitness on resting metabolic rate.

A cross-sectional study was designed to determine the relationship between aerobic fitness and resting metabolic rate (RMR) in 69 males exhibiting a wide range of aerobic fitness levels (VO2max = 32.8-78.1 mL.kg-1.min-1). The results of this study indicated that RMR was not significantly different between trained and untrained individuals when expressed in kJ.kg fat-free weight-1.hr-1 or using an ANCOVA with fat-free weight as the covariate and RMR as the dependent variable (F ratio = 0.353, P less than 0.70). In addition, this study also failed to support a previously suggested hypothesis that an elevated RMR may only be observed in those individuals exhibiting both high VO2max values and currently training a minimum of 12-16 h/wk. Thus, the results of this study strongly suggest that RMR is independent of both a person's current aerobic level and training status.     

The difference between the basal metabolic rate and the sleeping metabolic rate in Japanese

Previous studies have demonstrated the difference between the basal metabolic rate (BMR) and the sleeping metabolic rate (SMR): however, the difference in the Japanese population has not yet been explored. This study examined the relationship between the BMR and SMR in ninety-four healthy Japanese subjects (37 males and 57 females, 39 +/- 12 y of age and 22.0 +/- 7.4% body fat) in a respiratory chamber. The SMR was significantly lower than the BMR (1416 +/- 245 vs. 1492 +/- 256 kcal/d): however, there was a highly significant correlation between the two (r = 0.867; p < 0.001). The ratio of SMR/BMR largely varied among individuals (0.95 +/-0.08, 8.4% of the coefficient of variation). The ratio was significantly lower in males than in females (0.93 +/- 0.10 vs. 0.97 +/- 0.06, p < 0.05). None of the anthropometric measures (age, weight, body mass index, body surface area or percent body fat) correlated with the ratio. These results showed that SMR was 95%, of BMR on average in a healthy Japanese group. However, when applied over a longer time period (24 h or more), the difference tends to become negligible for most analyses in a group. Although the difference between SMR and BMR will induce a 5% gap of physical activity level defined as the total energy expenditure divided by the BMR or SMR, this factor seems to have little practical importance in epidemiological research.     

The status of the 1990 objectives for physical fitness and exercise

During the past 5 years, considerable progress has been made in clarifying the relationship between physical activity and health and in collecting previously unavailable information about the activity levels of children and adults. Several of the objectives are likely to be achieved by 1990. Nevertheless, important questions remain to be answered, and data necessary to know the status of some objectives are not available. The established benefits of regular physical activity include a reduced risk of coronary heart disease, desirable weight control, and reduced symptoms of anxiety and mild-to-moderate depression. Other health effects appear likely, but are less firmly established. The salubrious effect of regular physical activity on reducing the risk of coronary heart disease appears to exist even at low levels of physical activity. More information is needed about the type and intensity of physical activity necessary to achieve the various health benefits ascribed to it. Although most people appear aware of the characteristics of activities likely to produce moderate to high levels of physical fitness, only 10-20 percent of the adult population participates in such activity. The number and effect of worksite physical fitness programs are too poorly documented to determine if the pertinent objectives can be achieved. Fewer than two-thirds of the number of children recommended in the objectives participate in daily physical education classes.     

Smoking, exercise, and physical fitness.

BACKGROUND. Research on smoking and physical activity provides strong evidence of smoking's negative impact and physical activity's positive impact on long-term health. However, evidence regarding the association between smoking and exercise activity and the independent effects of these factors on fitness is lacking. METHODS. The associations among exercise activity, smoking behavior, and physical fitness were examined in 3,045 Navy personnel. Exercise and smoking behaviors were measured using a lifestyle survey. Physical fitness was assessed using scores on the Navy's Physical Readiness Test. Analyses of variance were conducted to examine the relationships among smoking status, exercise activity, and PRT performance. Multiple regression procedures were used to examine the relationship between smoking and physical fitness after statistically controlling for the effects of exercise. RESULTS. Smoking was associated with lower exercise levels and lower physical endurance--both cardiorespiratory (1.5-mile run) and muscular (sit-ups). After controlling for exercise activity, smoking remained significantly associated with lower physical endurance but was not related to overall body strength (lean body mass) or percentage body fat. CONCLUSION. Smoking is a detriment to physical fitness even among relatively young, fit individuals. Study findings suggest that smokers will have lower physical endurance than nonsmokers, even after differences in the average exercise levels of smokers and nonsmokers are taken into account. Cigarette smokers should be given strong encouragement to stop smoking as part of any effort to improve physical fitness.     

Intra-individual variation of basal metabolic rate and the influence of daily habitual physical activity before testing

The present study determined the intra-individual variation of BMR measurements, using a standard out-patient protocol, with the subjects transporting themselves to the laboratory for the BMR measurements after spending the night at home. The effect of a non-fasting state and variation in daily habitual physical activity the day before testing was evaluated. Eight male and eleven female subjects participated in three BMR measurements with 2-week intervals. Physical activity was estimated with a tri-axial accelerometer for movement registration, during the 3 d before each BMR measurement. There were no significant differences in estimated BMR (ANOVA repeated measures, P=0.88) and in physical activity (ANOVA repeated measures, P=0.21). Mean within-subject CV in BMR was found to be 3.3 (SD 2.1) %, ranging from 0.4 to 7.2 %. Differences between BMR measurements could not be explained by differences in physical activity the day before; however the mean within-subject CV in BMR changed from 5.7 to 5.2 % after correcting for within-machine variability and from 5.2 to 3.3 % after excluding five measurements because of non-compliance to the protocol including fasting. In conclusion, BMR values measured with a standard out-patient protocol are sufficiently reproducible for most practical purposes despite the within-subject variability in physical activity the day before the measurement. For this purpose, however, non-fasting subjects must be excluded and a regular function check of the ventilated-hood system is recommendable.     

体育锻炼动机对青少年运动量及有氧适能的影响

探讨动机理论视角下体育锻炼对青少年运动量及有氧适能的影响,为促进青少年身心健康提供依据.方法 随机选取青岛市3所中学共1 122名学生,采用体育锻炼动机问卷对研究对象体育锻炼动机进行量化,根据《国家学生体质健康标准》对学生有氧适能进行评价,按照运动训练学计算学生运动负荷,观察动机、有氧适能、运动负荷之间的内在相关性及动机对另外两者的预测作用.结果 被试体育锻炼动机5个维度与有氧适能、运动量整体得分之间相关均有统计学意义(P值均<0.05),但外貌维度与体育锻炼时间、次数,健康维度与体育锻炼次数,锻炼强度与有氧适能,锻炼次数与锻炼时间相关均无统计学意义(P值均>0.05);体育锻炼动机各维度对运动量具有预测作用,预测能力从大到小依次为能力(B=0.320)、愉快(B=0.312)、关联(B=0.269)、健康(B=0.258)、外貌(B=0.156);体育锻炼动机对其有氧适能也存在预测价值,但5个维度中仅愉快(B=0.145)、能力(B=0.214)、关联(B=0.176)存在预测价值;运动量对有氧适能有预测价值(B=0.171,P<0.01).结论 通过激发青少年体育锻炼动机,可以强化其运动量,提高身体有氧适能水平,最终促进青少年体育锻炼和体质水平的提高.     

The constancy of basal metabolic rate in free-living male subjects

The object of this work was to investigate the constancy of basal metabolic rate (BMR) over time. The BMR was measured in a group of healthy free-living adult men on three separate occasions over some 2 years. Analysis of variance showed that the coefficient of variation within subjects was 4 per cent and between subjects 8 per cent. The results are compared with those of earlier workers, from Zuntz onwards, who made serial measurements of BMR on the same subjects.     

纳西族中小学生体质健康状况及其与体育锻炼行为的关系

了解纳西族中小学生体质健康现状及其与体育锻炼行为的关系,为更好地开展青少年体质健康提供参考.方法 对云南丽江市2 636名纳西族中小学生进行体质测查,参照《国家学生体质健康标准》评价学生的体质水平,并分析纳西族中小学生体质与体育锻炼行为的关系.结果 7~18岁纳西族学生体质优秀率为3.1%,良好率为17.5%,及格率为65.6%,不及格率为13.9%.男、女生体质得分随学段升高均呈下降趋势(F值分别为28.133,11.727,P值均<0.01).男生(71.44±11.22)体质得分高于女生(70.48±10.29),差异有统计学意义(t=2.268,P<0.05).不同年校运会次数、每周体育课节数、体育课喜好、长跑意愿和每天体育锻炼时间学生体质得分差异均有统计学意义(F值分别为8.090,13.328,4.289,10.236,4.421,P值均<0.01).结论 纳西族中小学生体质现状喜忧参半.建议纳西族学生体质促进应注重学段和性别差异,确保体育活动时间,引导学生树立积极的体育锻炼态度.     

The influence of different methods on basal metabolic rate measurements in human subjects

While collating basal metabolic rate (BMR) measurements made worldwide it becomes important to know how different instruments compare with each other and whether errors in methodology could account for the differences in BMRs measured. BMRs of 34 healthy individuals were measured by using five different instruments in various combinations. Results show that energy outputs were comparable between the oxylog. Hartmann and Braun Metabolator, ventilated tent and hood, and whole-body indirect calorimeter: small differences, if any, were not statistically significant. However, significant interactions existed between subjects with the ventilated tent and hood and calorimeter when measurements were taken in subjects who were unaccustomed to the apparatus. When converting O2-consumption measurements to energy output, some instruments make assumptions that introduce a variable error in the final result, which may lead to systematic errors during the compilation of large databases of human BMRs.     

Physical activity and exercise to achieve health-related physical fitness components

To improve health and fitness effectively through physical activity or exercise, we need to understand how this comes about. For many of these changes, the stimulus has been grossly defined in terms of type, intensity, duration, and frequency of exercise, but for others a dose-response relationship has not been determined. Physical activity that appears to provide the most diverse health benefits consists of dynamic, rhythmical contractions of large muscles that transport the body over distance or against gravity at a moderate intensity relative to capacity for extended periods of time during which 200 to 400 kilocalories (or 4 kilocalories per kilogram of body weight) are expended. For optimal health benefits, such activity should be performed daily or at least every other day and should be supplemented with some heavy resistance and flexibility exercises. The greatest benefits are achieved when the least active individuals become moderately active; much less benefit is apparent when the already active individual becomes extremely active. Overexertion or inappropriate exercise can produce significant health risks. Research is needed to characterize better the health-promoting features of physical activity and exercise.     

The effect of altered dietary carbohydrate content on the metabolic responses to physical exercise in insulin-dependent diabetic subjects

The effects of two isoenergetic 8.4 MJ (2000 kcal) diets containing 40% and 65% of total energy from carbohydrate, respectively, were studied in six insulindependent diabetics in relation to the metabolic responses to physical exercise. Each subject followed both diets in turn for one week. Additionally, the effects of a pre-exercise supplement of either 50 g carbohydrate (as glucose polymer) or placebo were measured.
Exercise induced a marked fall in blood glucose levels of similar magnitude on both diets ( P < 0.05) in the absence of supplementary carbohydrate and a significant increase ( P < 0.01) when the supplement was provided. Insulin concentrations were virtually unaltered on either diet or supplement when compared before and after exercise ( P < 0.5).
Blood levels of the gluconeogenic precursors (lactate, pyruvate, alanine and glycerol) were significantly increased after exercise in the case of both diets with or without supplementary carbohydrate (0.02 < P < 0.05).
Basal and post-exercise levels of glucagon, cortisol, 3-hydroxybutyrate, catecholamines and free fatty acids (FFA) were generally similar and not significantly different in any of the treatment conditions.
These data demonstrate that the metabolic and hormonal response to exercise is similar in insulin-dependent diabetics receiving conventional injection therapy on standard diets (40% carbohydrate) and high carbohydrate containing diets (65% carbohydrate).     

智力残疾学生体质运动干预效果评价

目的探讨运动干预对智力残疾学生身体形态、生理功能的影响,为改善智力残疾学生体质提供依据。方法采用体质监测、文献资料调研和数理统计、对比分析等方法,将北京市3所培智学校87名智力残疾学生随机分为干预组与对照组,分别测试运动干预前、后身体形态、生理功能、身体素质与平衡能力指标。结果实施运动干预12个月后,干预组身体形态各项指标均略高于对照组,差异均无统计学意义(P值均>0.05);2组生理功能指标、握力及立定跳远指标差异有统计学意义(P值均<0.05);单足闭眼及单足睁眼时间差异均无统计学意义(P值均>0.05)。结论运动干预使智力残疾学生的身体形态有"更强壮"的趋势,可显著提高智力残疾学生的身体生理功能及上、下肢肌肉力量。     

The effect of lifestyle modification on physical fitness and work ability in different workstyles

It is generally considered that physical fitness is affected by daily life activities including leisure time activity and working time activity. The aim of this study is to investigate the effects of different levels of physical activity at work on physical fitness, analyze the effects of 12-week lifestyle modification outside of working hours on physical fitness, work satisfaction and subjective symptoms, and to consider the role of lifestyle modification in occupational health. Lifestyle modification, consisting of aerobic exercise and diet counseling, was conducted for 12 weeks. The data before and after the intervention from 49 male workers were obtained. Physical fitness such as exercise endurance, flexibility, agility, balance, muscular strength, muscular endurance, and muscular power was measured before and after the intervention. The subjects were asked to fill out questionnaires about their work activities, subjective complaints, and work satisfaction. Subjects were divided into active work group (n = 14) and sedentary work group (n = 35) for analysis according to their work activities. As for differences in physical fitness due to different levels of physical activity, the active work group had superior exercise endurance and balance compared to the sedentary work group. In addition, the sedentary work group tended to experience greater fatigue than the active work group. In the active work group, flexibility and muscular strength were significantly increased with lifestyle modification and, in the sedentary work group, exercise endurance, flexibility and muscular endurance were significantly improved while balance also showed a tendency to improve. In the sedentary work group, lifestyle modification resulted in reduced fatigue and stiff neck as well as an increased work satisfaction. In the active work group, no change was observed in complaints or work satisfaction, but improved physical fitness led to a reduction in subjective complaints and an increase in work satisfaction. The level of physical activity at work contributes to the physical fitness of the worker and the addition of aerobic exercise in the worker's leisure time improves physical fitness and thereby contributes to increased work ability regardless of differences in the level of physical activity at work.     

Effects of exercise intensity on physical fitness and risk factors for coronary heart disease

OBJECTIVE: To determine whether "low-intensity" exercise (walking) and "high-intensity" exercise (aerobic dance), when added to a weight loss diet, have different effects on coronary heart disease (CHD) risk factors and physical fitness. RESEARCH METHODS AND PROCEDURES: Ninety obese women were divided into diet only (DO), diet plus walking (DW), and diet plus aerobic dance (DA) groups. DXA was used to evaluate segmental body composition. Leg-extension strength and maximal oxygen uptake (VO2max) were the indicators of physical fitness. Blood pressure, lipoproteins, and fasting glucose were used as indices for CHD risk factors. These items were measured before and after a 14-week intervention period. RESULTS: Whole-body plus all segmental fat masses were significantly reduced (p < 0.001). Reductions in whole-body and lower-limb fat- and bone-free masses were significantly less (p < 0.01) in the DA group (-1.5 and -0.1 kg, respectively) compared with the DO (-2.1 and -0.4 kg, respectively) and DW (-2.5 and -0.5 kg, respectively) groups. Improvements in leg-extension strength and VO2max were significantly greater (p < 0.05) in the DA group compared with the DO group. The CHD risk factors clearly improved (p < 0.05) within each group. Reductions in low density lipoprotein-cholesterol and fasting glucose were significantly greater (p < 0.05) in the DA group compared with the DO and DW groups. DISCUSSION: Adding higher intensity aerobic dance to a weight-loss diet program may help maintain fat- and bone-free mass and may be more effective in improving CHD risk factors compared with low-intensity walking.     

Status of the 1990 physical fitness and exercise objectives--evidence from NHIS 1985

The 1985 National Health Interview Survey (NHIS) Health Promotion and Disease Prevention Questionnaire provides information regarding the status of 4 of the 11 physical fitness and exercise objectives for 1990. A specially developed scoring algorithm was used to determine the percentage of persons participating in appropriate physical activity (that is, "exercise which involves large muscle groups in dynamic movement for periods of 20 minutes or longer, 3 or more days per week, and which is performed at an intensity of 60 percent or greater of an individual's cardiorespiratory capacity" and three other categories: regular activity, but not appropriate physical activity; irregular activity; and those who were sedentary. Results revealed that the young and persons of relatively high socioeconomic status are more likely to perform appropriate physical activity in their leisure time. When rigid criteria were used, only 5.1 percent of those surveyed knew the appropriate duration, frequency, and intensity of physical activity needed to strengthen the heart and lungs. It was not possible to determine if exercise prevalence has increased in recent years; however, it will be possible to detect trends in the future when this survey is repeated in 1990.