Self-guided brisk walking training with or without poles: a randomized-controlled trial in middle-aged women.

Walking with poles (Nordic walking, NW) has become popular. We compared training responses of brisk walking (W) or NW on cardiorespiratory and neuromuscular fitness. We randomized 121 non-obese sedentary women (aged 50-60) to an NW or W group (NWG, WG), to train 40 min four times weekly for 13 weeks. Intensity was based on subjective perception of exertion. Cardiorespiratory performance was assessed in four levels corresponding to 50%, 65%, 80% and 100% of peak VO(2). Fifty-four NWG and 53 WG subjects completed the study. The mean intensity was about 50% of heart rate (HR) reserve. The baseline peak VO(2) was 25.8 (SD 3.9) mL/min/kg. Both groups improved peak VO(2) similarly (NWG 2.5 mL/min/kg, 95% confidence interval (CI) 1.9-3.3; WG 2.6, CI 1.9-3.3). In the submaximal stages while walking with or without poles, HR and lactate decreased after training in both groups, but the changes were not statistically significantly different between the groups. Of the neuromuscular tests after training, the only significant difference between the groups was in the leg strength in the one-leg squat, favoring WG. In conclusion, both training modes improved similarly health-enhancing physical fitness, and they were feasible and safe.

Use of heart rate to predict energy expenditure from low to high activity levels.

This study evaluated the ability to use the relationship between heart rate (HR) and oxygen uptake (VO2 ) to estimate energy expenditure (EE) from low to high physical activity with different HR-based prediction equations. General prediction equations were established based on the individual relations between HR and EE. Possibilities to improve the EE estimation with using alternatives for respective HR were also assessed. The alternatives were % of HR reserve: 100 x [(activity HR - resting HR)/(maximal HR - resting HR)], (HRR), and the difference between activity HR and resting HR (activity HR - resting HR), (HRnet). Forty-two men (age mean 36.5 [sd 7.6] y, BMI 24.5 [2.4] kg x m(-2), VO2 max 45.2 [6.5]) kg x ml x min(-1) and 47 women (mean age 37.5 [9.5], BMI 23.3 [3.4], VO2 max 36.3 [5.4]) performed an exercise test consisting of physically low-activity tasks and a maximal treadmill uphill walking test. Respiratory gases were obtained from indirect calorimetry. HR was registered by electrocardiography and EE was calculated from (VO2 ) and carbon dioxide (VCO2 ) production. Generalised linear models with random effects were used for the prediction of EE. EE values of the tests (one value at each intensity level) were predicted in separate models by the respective HR, HRR or HRnet values. The other predictors used in all models were body weight, sex and the intensity of exercise. The standard error of estimate (SEE) was 1.41 kcal x min(-1) (5.89 kJ) in the model with HR variable as a predictor, 1.01 kcal x min(-1) (4.22 kJ) with HRR variable, and 1.08 (4.51 kJ) with HRnet variable. The results show that the prediction of EE is more accurate if HRR or HRnet are used in prediction equation instead of HR.

Weight and diet concerns in Finnish female and male athletes.

UNLABELLED: PURPOSES AND METHODS: Factors related to eating disorders were studied in five groups of female (N = 173) and male (N = 190) athletes, and in female (N = 79) and male (N = 61) controls. Factors associated with menstrual status were also examined. RESULTS: The sum of drive for thinness and body dissatisfaction subscales in the Eating Disorders Inventory was higher (P < 0.05) in female controls (median: 5; 25th and 75th percentiles: 1 and 14) than in endurance athletes (0; 0 and 2). The male groups did not differ from each other (P = 0.08) or from female subjects (P = 0.62). The preferred weight loss in the female controls (-4.0 kg; -6.2 and -2.0) was larger (P < 0.05) than in most athletic groups. Males, on average, did not want to lose weight (different from females, P < 0.001). The prevalence of weight reduction attempts (85%) in female weight-class athletes was higher (P < 0.05) compared with endurance and ballgame athletes and the controls (29-58%). In males, the frequency (93%) of weight reduction attempts was also highest in the weight-class athletes (P < 0.05). The prevalence of menstrual disturbances was 27-37% in aesthetic, endurance, and weight-class athletes, and 5% in controls (P = 0.06). CONCLUSIONS: The results confirmed that the risk for eating disorders is dependent on the type of sport. The claim that some female athlete groups are at greater risk than controls did not receive evidence.

Assessment of energy expenditure in overweight women.

PURPOSE: To compare field measures of average daily energy expenditure (ADEE) against criterion data by the doubly labeled water method (DLW) in overweight women. METHODS: The subject were 20 overweight (BMI 29.9 +a- 3.0 kg.m-2) premenopausal women. Energy expenditure was measured by DLW and by the factorial method (activity diary, two techniques differing by method to obtain resting energy expenditure, REE), heart-rate monitoring (HR, two techniques differing by the FLEX-point to discriminate sedentary and activity HR), accelerometer, and pedometer. RESULTS: The ADEE(DLW) was 10.26 +a- 1.1 MJ.d-1. The mean bias (ADEE by the alternative minus ADEE(DLW) was smallest for the accelerometer (+ 0.08 +a- 1.63 MJ) and HR-FLEX10 (+ 0.11 +a- 1.67 MJ). The HR-FLEX(0) technique (lower FLEX-point) overestimated ADEE by + 1.18 (+a- 1.97 MJ). However, the random error (SD of bias) was smaller for both factorial techniques (REE measured: -0.48 +2- 0.81 MJ; REE calculated from the WHO equation: -0.22 +2- 0.88 MJ). CONCLUSION: The results show that simple factorial methods may assess ADEE with small random errors in population with a rather narrow range of physical activity. The accelerometer and HR with the higher FLEX-point have comparable results with smaller bias but larger random error compared with the factorial techniques.