Breath holding with water immersion in synchronized swimmers and untrained women.

Breath holding (BH) and water immersion induce several physiological responses. Individuals, who are BH trained tend to have an advantage versus untrained subjects. This study compared physiological responses to BH at rest between synchronized swimmers (SS) and controls (C). Each participant performed five resting BH periods in water. Breath holding periods were significantly longer for SS (109.8 +/- 39.3 vs. 78.3 +/- 25.0s), despite a similar end tidal partial pressure of carbon dioxide and oxygen following BH. Recovery times after BH were similar for oxygen consumption, ventilation, and blood oxygen saturation. Synchronized swimmers (SS) experienced bradycardia at 45s of max BH, whereas C did not (60 +/- 9 vs. 65 +/- 14 b x min(-1)). A significant oxygen conservation effect occurred for SS in only one BH trial. These results suggest that SS exhibited an enhanced ability to breath hold with similar respiratory responses but a lower heart rate (HR) during recovery, suggesting a better adaptation to BH.

Associations among the food environment, diet quality and weight status in Cree children in Québec.

OBJECTIVE: To explore the relationship among children's diet quality, weight status and food environment in subarctic Canada. DESIGN: In the cross-sectional study, children's BMI was calculated, diet quality was assessed using three 24 h dietary recalls and children were asked about their home food environment and source of meals. SETTING: Two Aboriginal Cree communities in northern Québec. SUBJECTS: Two hundred and one children in grades 4-6. RESULTS: The majority (64.2%) of children were overweight (29.9%) or obese (34.3%). Weight status was not associated with reported restaurant meal frequency or the home food environment. The 18% of children who consumed three or more restaurant meals in the three days of recall consumed, on average, 2004 kJ (479 kcal) more energy daily than children consuming no restaurant meals and had higher intakes of fat, saturated fat, Ca and soda. Most foods contributing to energy and dietary fat were energy-dense market foods of low nutritional value such as sweetened beverages and snack foods. Only 68% of children reported often having fruits and vegetables in the home and 98.5% of children consumed less than 5 fruits and vegetables daily. Many children (42.8%) were at risk of Zn inadequacy. Only 19% of children consumed 2 or more servings of milk daily, and the mean intakes of Ca and vitamin D were below the recommended adequate intake. Traditional game meat was consumed infrequently, but contributed significantly to Fe and Zn intake. CONCLUSIONS: Childhood obesity in subarctic communities prevailed in a food environment typified by high-energy-density commercial foods of low nutritional value.

Diabetes awareness and body size perceptions of Cree schoolchildren.

Native American Indians and First Nations are predisposed to obesity and diabetes. A study was done to understand Cree schoolchildren's diabetes awareness and body size perceptions in two communities that had diabetes awareness-raising activities in the Province of Quebec, Canada. Children (N = 203) in grades 4-6 were classified into weight categories using measured heights and weights and grouped on diabetes awareness based on dichotomous responses to the question 'Do you know what diabetes is?' Children selected a drawing of an American Indian child whom they felt most likely to get diabetes and described their body size perception using a closed response question. Although 64.5% of children were overweight or obese, most (60.1%) children considered their body size to be 'just right', with 29.6% considering it 'too big' and 10.3% considering it 'too small'. A minority (27.6%) of children had diabetes awareness. These children were more likely than children without diabetes awareness to consider their body size too big (42.9 versus 24.5%) and to choose an obese drawing as at risk for diabetes (85.7 versus 63.3%, odds ratio 3.48 and 95% confidence interval 1.53-7.91). Culturally appropriate health education programs to increase schoolchildren's diabetes awareness and possibility to have a healthy body weight are important.

Obesity, adiposity, physical fitness and activity levels in Cree children.

OBJECTIVES: To describe the levels of obesity, adiposity measures, physical activity and fitness in Cree children aged 9-12 years. STUDY DESIGN: Cross-sectional survey. METHODS: The study took place in northern Quebec, Canada. Height, body mass, waist circumference and five skinfold thicknesses were measured. Physical activity was assessed by having children wear a pedometer for two days. Children performed the 20-metre shuttle run test (SRT) to determine their physical fitness level. RESULTS: Of 82 participating children, 33% were overweight (but not obese) and 38% were obese according to an international reference. The mean sum of five skinfold measures exceeded the 95th percentile of Canadian children. Compared with the Third National Health and Nutrition Examination Survey, the majority of children exceeded the 85th percentile for waist circumference (62%) and at the suprailiac (80%), subscapular (72%), and triceps (54%) skinfold sites. 90% of children scored below the 20th percentile in the SRT compared with normative data from Quebec children. Based on pedometer scores, only 49% of children were sufficiently active. CONCLUSIONS: There is a high prevalence of overweight and central adiposity in this population, with low physical activity and fitness levels. This profile may result in adverse health outcomes.

Validity of test score interpretations for three self-concept measures based on differing theoretical models.

Three theoretical models have been proposed to represent self-concept: (a) unidimensional; (b) multidimensional; (c) multidimensional hierarchical. Inventories have been developed under each of the three competing theoretical models; which model best represents self-concept is unclear. Typically, self-concept construct validation has utilized various approaches including correlational, multitrait-multimethod, and factor analytic methods. Another method, however, for assessing validity would be to determine the consequences of score interpretations using different measures specific to each of the theoretical models. This paper examined Messick's notion (1989) of the validity of test-score interpretations as applied to three of the most widely used measures derived under each of the three different theoretical models of self-concept. Results suggest that overall multidimensional measures are more consistent in classifying individual's self-concept than unidimensional measures.

A comparison of the physiological responses to underwater arm cranking and breath holding between synchronized swimmers and breath holding untrained women.

Exercise and breath holding in the water such as that performed in the sport of synchronized swimming may evoke the physiological consequences of the diving response. The purpose of this study was to investigate the physiological responses of breath holding during underwater arm cranking in synchronized swimmers who are trained in breath holding and compare these responses to untrained women. Each participant performed 6 breath holding periods in the water (2 × 10s, 2 × 20s and 2 × 25s) with 2 minutes of normal breathing in between, in either an ascending or descending order while performing arm crank exercise. The intensity of arm crank exercise was set below the individual ventilatory threshold. Both synchronized swimmers and controls were matched on sitting height and then randomly divided into 2 groups: one group started breath holding with the longest (25s) breath holding periods while the other group began breath holding with the shortest (10s) breath holding periods. The synchronized swimmers experienced a significant decrease in heart rate while breath holding for 20 and 25s but the changes in heart rate for the control group was not consistent between subgroups. Full recovery from breath holding was identified for minute ventilation after 25s of recovery from breath holding for all groups. Results suggest synchronized swimmers exhibited a better adaptation to breath holding while exercising underwater.

A time-motion analysis of elite solo synchronized swimming.

PURPOSE: To determine the total amount and relative time periods of face immersion (FI) in a synchronized swimming solo routine and the relationship between FI, distance covered, and the technical-merit score of the 11 top Canadian soloists at a synchronized swimming national championship (mean age 20 +/- 1.8 y, height 173.3 +/- 4.1 cm, and body mass 58.3 +/- 4 kg). METHODS: Videotape and timing of solo performances combined with manual tracking of pool patterns. RESULTS: Analysis of performance revealed that an average of 18 FI periods, mean of 6.8 s, were performed for an average total time of 133.7 +/- 27.1 s (range 102.2 to 199.8 s). The average longest FI time period was 25.45 +/- 6.2 s (range 18.18 to 38.72 s), and most (10/11) of these were in the first third of the solo. The mean total horizontal distance covered was 57.61 +/- 6.84 m (range 48.61 to 68.2 m), and the total horizontal distance covered relative to time was 0.276 +/- 0.034 m/s (range 0.235 to 0.340 m/s). No significant relationships were found between any of the FI periods and the distance covered or between the technical-merit score and FI periods. Each solo contained 6 to 8 underwater sequences, none of which were longer than 40 seconds, the cutoff deemed dangerous by FINA (Fédération Internationale de Natation). CONCLUSION: This study shows that the times underwater for solos in Canada are within safety limits recommended by FINA and that judging in Canada is not related to underwater periods of swimming.

Central adiposity and associated lifestyle factors in Cree children.

Aboriginal children are prone to central adiposity (CA), a component of the metabolic syndrome. The objective of this study was to determine if lifestyle factors were associated with CA in Canadian Cree children. Children aged 9-12 years were classified as having CA if their waist circumference met or exceeded the 85th percentile of the NHANES III reference. Weight status was determined using the CDC growth reference, dietary intake using three 24 h dietary recalls, physical activity using pedometers, and fitness by completion of the 20 m shuttle run test. Of the 178 children (79% participation rate), 32.6% were normal weight, 23.6% were overweight, and 43.8% were obese. Half (52.2%) of the children had CA (97.4% of obese children, 35.7% of overweight children, and 2.2% of normal weight children). Waist circumference was negatively correlated with pedometer step counts (r = -0.187, p = 0.012) and shuttle run time (r = -0.508, p < 0.001). In children with CA, waist circumference was positively correlated with sweetened beverage intake (r = 0.250, p = 0.016). The odds ratio (adjusted for age and sex) for CA for children consuming 3 or more fruits and vegetables per day was 0.43 (95% CI 0.18 - 0.98), for meeting step recommendations for a healthy body weight was 0.45 (95% CI 0.24 - 0.84), and for relative fitness was 0.12 (95% CI 0.04 - 0.33). CA was prevalent in children who were overweight and obese. Preventive strategies might include promoting a healthy diet, physical activity, and fitness.