摘要:

Obesity is a worldwide public health problem. One in three Canadians is overweight, a prevalence that is already high and increasing. Moreover, 54% of men and 37% of Canadian women are characterized as abdominally obese, the phenotype that is strongly associated with cardiovascular disease and type II diabetes. These observations underscore the importance of considering the efficacy of methods commonly used to reduce total and abdominal obesity. These strategies include a decrease in energy intake (diet), an increase in energy expenditure (exercise), or pharmacological intervention. The combination of diet and exercise is more commonly prescribed, with pharmacological intervention suggested only when lifestyle changes fail to achieve weight loss.The aim of this report is to review current knowledge regarding the influence of diet and exercise as treatment strategies for obesity reduction and provide recommendations for attaining and maintaining a healthy weight. The importance of diet composition in the treatment of obesity is also considered.Key words:body fat, weight loss, exercise, diet

ISSN:1066-7814    

DOI:10.1139/h00-001

出版商:NRC Research Press    

年代:2000

数据来源: NRC

摘要:

Exercise and training responses in women are briefly reviewed. Part I of the paper considers the influence of gender on such responses. The average woman has a smaller inherent aerobic power and less muscular strength than a man, reflecting sociocultural influences, physical size, body composition, and hormonal milieu. Nevertheless, the best-trained women can out-perform sedentary men. The handicap of the average woman is offset by a lighter body mass and a tendency to metabolize fat rather than carbohydrate during exercise. A lack of anabolic hormones may limit training increases of muscle bulk in the female. A low initial fitness may enhance the scope for training tolerance, but it also limits tolerance of conditioning. Nevertheless, women seem less vulnerable than men to exercise-induced sudden death and overtraining. Part II of the review considers the influence of the menstrual cycle and pregnancy upon exercise and training responses. Physical activity programmes for young women should take account of possible pregnancy. Potential dangers to the foetus include an excessive rise of core body temperature, a decrease of maternal blood sugar, and foetal hypoxia. Nevertheless, regular moderate exercise generally has a favourable impact upon pregnancy outcomes.Key Words:sex differences, sociocultural issues, biological differences, physical activity, conditioning, menstruation, pregnancy, employment standards

ISSN:1066-7814    

DOI:10.1139/h00-002

出版商:NRC Research Press    

年代:2000

数据来源: NRC

摘要:

not available

ISSN:1066-7814    

DOI:10.1139/h00-003

出版商:NRC Research Press    

年代:2000

数据来源: NRC

摘要:

This study investigated the efficacy of SPORTTM(a popular dietary supplement) in improving performance and assisting recovery in 9 trained athletes. In a double-blind, crossover experiment, subjects ran at workloads of 60 and 80% of peak oxygen uptakefor 5 min each with 5 min recovery after each bout and at 100%until exhaustion. Two capsules of either SPORTTMor a gelatin placebo were administered 1 hr prior to exercise and immediately after each workload. Heart rate (HR) and blood lactate (BLa) were measured at 1 hr prior to exercise, immediately after the 100% exercise bout and at 5, 10, 20, and 45 min during recovery. No significant differences between treatments on HR and BLa measures at any of the 6 time periods, or on subjects' time to exhaustion were found. Under the conditions of this experimental design, SPORTTMhad no beneficial effects on performance or recovery in trained athletes.Key Words:blood lactate, dioscorea, heart rate, ergogenic aid, time to exhaustion

ISSN:1066-7814    

DOI:10.1139/h00-004

出版商:NRC Research Press    

年代:2000

数据来源: NRC

摘要:

We examined the effects of androstenedione supplementation on the hormonal profile of 10 males and its interaction with resistance exercise. Baseline testosterone, luteinizing hormone, estradiol, and androstenedione concentrations were established by venous sampling at 3 hr intervals over 24 hr. Subjects ingested 200 mg of androstenedione daily for 2 days, with second and third day blood samples. Two weeks later, they ingested androstenedione or a placebo for 2 days, in a double-blind, cross-over design. On day 2, they performed heavy resistance exercise with blood sampled before, after, and 90 min post. The supplement elevated plasma androstenedione 2-3-fold and luteinizing hormone ∼70% but did not alter testosterone concentration. Exercise elevated testosterone, with no difference between conditions. Exercise in the supplemented condition significantly elevated plasma estradiol by ∼83% for 90 min. Androstenedione supplementation, thus, is unlikely to provide male athletes with any anabolic benefit and, with heavy resistance exercise, elevates estrogen.Key Words:testosterone, luteinizing hormone, estradiol, fluid shifts, resistance exercise

ISSN:1066-7814    

DOI:10.1139/h00-005

出版商:NRC Research Press    

年代:2000

数据来源: NRC