Fitness of Canadian children and youth: results from the 2007-2009 Canadian Health Measures Survey.

BACKGROUND: The fitness of Canadian children and youth has not been measured in more than two decades, a period during which childhood obesity and sedentary behaviours have increased. This paper provides up-to-date estimates of the fitness of Canadians aged 6 to 19 years. DATA AND METHODS: Data are from the 2007-2009 Canadian Health Measures Survey (CHMS), the most comprehensive direct health measures survey ever conducted on a nationally representative sample of Canadians. Descriptive statistics for indicators of body composition, aerobic fitness and musculoskeletal fitness are provided by sex and age group, and comparisons are made with the 1981 Canada Fitness Survey (CFS). RESULTS: Fitness levels of children and youth have declined significantly and meaningfully since 1981, regardless of age or sex. Significant sex differences exist for most fitness measures. Fitness levels change substantially between ages 6 and 19 years. Youth aged 15 to 19 years generally have better aerobic fitness and body composition indicators than 20- to 39-year-olds. INTERPRETATION: This decline in fitness may result in accelerated chronic disease development, higher health care costs, and loss of future productivity.

Fitness of Canadian adults: results from the 2007-2009 Canadian Health Measures Survey.

BACKGROUND: Estimates of obesity, based on body mass index (BMI) reveal that Canadian adults have become heavier over the past quarter century. However, a comprehensive assessment of fitness requires additional measures. This article provides up-to-date estimates of fitness levels of Canadians aged 20 to 69 years. Results are compared with estimates from 1981. DATA AND METHODS: Data are from the 2007-2009 Canadian Health Measures Survey (CHMS). Historical estimates are from the 1981 Canada Fitness Survey. Means, medians and cross-tabulations were used to compare fitness levels by sex and age group and between survey years. RESULTS: Mean scores for aerobic fitness, flexibility, muscular endurance and muscular strength declined at older ages, and BMI, waist circumference, skinfold measurements and waist-to-hip ratio increased. Males had higher scores than females for aerobic fitness, muscular endurance and muscular strength; females had higher scores for flexibility. Muscular strength and flexibility decreased between 1981 and 2007-2009; BMI, waist circumference and skinfold measurements increased. INTERPRETATION: Based on results of the fitness tests and anthropometric measurements, many Canadian adults face health risks due to suboptimal fitness levels.

Total peptide YY is a correlate of postprandial energy expenditure but not of appetite or energy intake in healthy women.

Peptide YY (PYY) and ghrelin have been associated with the regulation of energy balance. The objectives of this study were to determine whether total ghrelin and PYY after a standardized meal predict appetite scores and ad libitum energy intake (EI) and to examine the relationship between total ghrelin and PYY and postprandial energy expenditure (PEE). Twenty-five premenopausal women (age, 50.4 +/- 2.0 years; body mass index, 23.5 +/- 2.2 kg/m(2)) were studied. Total PYY, total ghrelin (enzyme-linked immunosorbent assay), EE (indirect calorimetry), and appetite scores (visual analogue scales) were measured fasting and every 30 minute for 3 hours after the ingestion of a standardized breakfast. Ad libitum EI was measured at lunch with a buffet-type meal. Peptide YY increased (P < .001) and total ghrelin decreased (P < .001) after breakfast. Significant changes in EE (P < .001) and appetite scores (P < .001) were noted postprandially. Appetite scores were consistently associated with ad libitum EI at lunch (r = -0.51 to 0.40, P < .05), whereas no association between EI and prelunch total ghrelin and PYY was observed. Finally, partial correlation analyses revealed that total PYY was a significant independent correlate of PEE at 60, 90, 120, and 150 minutes (r = 0.37-0.51, P

Validity of the Actical accelerometer step-count function.

PURPOSE: To assess the validity of the new Actical accelerometer step count function. METHODS: Actical step counts were compared according to two criterion standards. 1) Eight Acticals were assessed using a mechanical shaker table under six different testing conditions. 2) Thirty-eight volunteers (aged 9-59 yr) wore eight Acticals and eight Actigraphs during treadmill walking (50 and 83 m.min(-1)) and running (133 m.min(-1)) for 6 min at each speed. Steps were counted during the second and fourth minutes of each speed by a trained observer. RESULTS: The correlation between Actical step counts and the mechanical shaker step counts was excellent (r = 1.0). Compared with visually counted steps, both the Actical and Actigraph step counts were significantly different at 50 m.min(-1); however, no significant differences were evident at 83 and 133 m.min(-1). The criterion-related validity correlations (r) for the Actical and Actigraph, respectively, were 0.73 and 0.52 at the slow walk condition and 0.99 and 0.99 at the normal walk and run conditions. CONCLUSION: The new step count function of the Actical accelerometer provides valid estimates of step counts at 83 and 133 m.min(-1) on a range of healthy participants.