Danielle R. Bouchard

Impact of resistance training with or without caloric restriction on physical capacity in obese older women.

Objective: To investigate the specific impact of resistance training (RT) with or without caloric restriction (CR) on physical capacity in obese older women. Design: Forty-eight postmenopausal obese women, physically independent and between the ages of 55 and 75 years were recruited. The women were randomly assigned to one of four groups (1: RT [n = 12], 2: CR [n = 12], 3: CR + RT [n = 12], or 4: control group [C; n = 12]) for 3 months. CR and CR + RT groups participated in a weekly group session on nutrition, and RT and CR + RT groups took part in a resistance training program. Physical capacity was measured with 11 different performance tests. A global physical capacity score (range, 0-44) was then computed using quartiles of each test. Body composition was measured by dual-energy x-ray absorptiometry. Results: Body weight, total fat mass, percentage of fat mass, and body mass index (kg/m2) significantly decreased in the CR and CR + RT groups (P < 0.01), whereas only the CR group showed a significant decrease in lean body mass (P < 0.05) after the 3-month program. The global physical capacity score significantly improved in the RT group (10.0 ± 8.8%; P < 0.01), compared with the C group after 3 months. Conclusion: Overall, the 3-month RT program alone had a greater effect on physical capacity than CR or CR + RT. Thus, a 3-month RT could help prevent long-term decreases in physical capacity in obese older women.

Short- and long-term effects of continuous versus intermittent restrictive diet approaches on body composition and the metabolic profile in overweight and obese postmenopausal women: a pilot study

ObjectiveThe objective of this study was to compare changes in body composition and the metabolic profile between women taking an intermittent diet (ID) and women taking a continuous diet (CD). MethodsTwenty-five obese postmenopausal women were randomized to an ID (n = 13) or a CD (n = 12). In the ID, 5-week energy restriction periods were followed by 5-week weight stabilization periods. In the CD, 15 weeks of energy restriction was followed by 5 weeks of weight stabilization. Outcome measures before, during, and after weight loss, as well as after a 1-year follow-up, were body weight and composition, waist circumference, resting metabolic rate, and fasting lipid and glucose levels. ResultsBody weight, waist circumference, percentage fat mass, and fat mass decreased significantly and similarly in both groups (P < 0.0001). Both groups showed similar overall decreases in plasma total cholesterol and triglycerides (all P < 0.05). Low-density lipoprotein cholesterol improved significantly in the CD group only, whereas fasting glucose decreased significantly in the ID group only. High-density lipoprotein cholesterol and resting metabolic rate remained stable in both groups. Fasting plasma triglyceride and glucose levels were the only metabolic variables to further improve after the fifth week of the protocol. At the 1-year follow-up, both interventions were associated with successful and similar weight loss maintenance and improvements in fasting plasma glucose levels. ConclusionsThe ID resulted in similar short- and long-term changes in body composition and metabolic profile compared with a CD. Most improvements occurred during the first 5 weeks of treatment in both interventions.

The effects of lifestyle interventions in dynapenic-obese postmenopausal women

Objective The aim of this study was to investigate the impact of caloric restriction (CR) and resistance training (RT) on body composition, metabolic profile and physical capacity in dynapenic-obese postmenopausal women. Methods Thirty-eight dynapenic-obese postmenopausal (age, 62.6 ± 4.1 y) women were randomly assigned to one of four groups (1, CR; 2, RT; 3, CR + RT; and 4, control) for a 12-week intervention. The independent variables were body weight, fat mass, and lean body mass (using dual-energy x-ray absorptiometry), waist circumference, fasting lipids and glucose, resting systolic and diastolic blood pressure, and physical capacity (6-min walk, chair stand, and one-leg stand tests). Results Body weight, fat mass, and waist circumference decreased similarly in the CR and CR + RT groups (all P ⩽ 0.05). However, only changes in the CR + RT group were significantly different from the control group (all P ⩽ 0.05). Total cholesterol, triglycerides, and systolic and diastolic blood pressure significantly decreased in the CR group (all P ⩽ 0.05); whereas total cholesterol, low-density lipoprotein cholesterol, and systolic blood pressure decreased in the CR + RT group (P ⩽ 0.05). Physical capacity improved significantly in the RT and CR + RT groups (all P ⩽ 0.05), with significant greater improvements in the RT group (P ⩽ 0.05). Conclusions Our results suggest that CR with or without RT is effective in improving metabolic profile, whereas RT is effective in improving physical capacity. The combination of RT and CR may be particularly relevant in maximizing improvements in physical capacity in dynapenic-obese postmenopausal women.

Risk of type 2 diabetes and cumulative excess weight exposure in the Framingham Offspring Study

AIM Mid-life obesity is associated with T2D risk. However, less is known about the cumulative effect of obesity during adulthood. METHODS Framingham Offspring Study participants who had an examination at 35±2 years and were initially free of T2D were included in this study (N=1026). A cumulative excess weight (CEW) score (year*kg/m²) was calculated until T2D diagnostic or the end of follow-up. RESULTS Eighty-four individuals (8.2%) developed T2D over 20±6 years. Mean CEW scores were 118.0±114.6 year*kg/m² in individuals who developed T2D and 30.2±91.4 year*kg/m² in those who did not develop T2D (P<0.01). T2D risk was doubled for each standard deviation increase in the CEW score (OR=1.99 [1.64-2.40]; P<0.001). However, CEW score was only significantly associated with T2D incidence for participants with a baseline BMI <25 kg/m² (OR =2.13 [1.36-3.36]; P<0.001). CONCLUSIONS Accumulating weight between the mid-thirties to the mid-fifties increases the risk of developing T2D. However, BMI in mid-thirties remains a stronger predictor of T2D risk.

Pilot study: can older inactive adults learn how to reach the required intensity of physical activity guideline?

Most individuals do not reach the recommended physical activity level of at least 150 minutes of aerobic exercise (AE) at moderate-to-vigorous intensity per week. For example, only 13% of older Canadian adults reach World Health Organization physical activity guideline (PAG). One of the reasons might be a difficulty identifying the required intensity. Twenty-five inactive older adults received one session about the AE-PAG and how to use a tool or strategy to help them identify AE intensity: heart-rate (HR) monitor (% of maximal HR; N = 9); manual pulse (% of maximal HR; N = 8); or pedometer (walking cadence; N = 8). Participants had 8 weeks to implement their specific tool with the aim of reaching the PAG by walking at home. At pre- and post-intervention, the capacity to identify AE intensity and AE time spent at moderate-to-vigorous intensity were evaluated. Only the two groups using a tool increased total AE time (both P < 0.01), but no group improved the time spent at moderate-to-vigorous intensity. No significant improvement was observed in the ability to correctly identify AE intensity in any of the groups, but a tendency was observed in the pedometer group (P = 0.07). Using walking cadence with a pedometer should be explored as a tool to reach the PAG as it is inexpensive, easy to use, and seemed the best tool to improve both AE time and perception of intensity.

Effects of rapid or slow weight loss on body composition and metabolic risk factors in obese postmenopausal women. A pilot study.

To compare the effect of rapid or slow weight loss (WL) on body composition and metabolic risk factors following a caloric restriction. Ten obese, postmenopausal women were matched for total body WL. Dependent variables were: body composition, lipid profile and blood pressure. Both groups decreased obesity measures (all P≤0.05) while lean body mass decreased in the rapid WL group (P≤0.05). Significant improvements in fasting triglyceride level and diastolic blood pressure were observed only in the slow WL group. A slower WL seems to be more beneficial to improve body composition as well as metabolic risk factors in postmenopausal women.

Lifestyle habits and physical capacity in patients with moderate or severe metabolic syndrome.

BACKGROUND Metabolic is a heterogeneous concept that includes five elements, each of which has individual thresholds that might be different when considered as a criterion in the metabolic syndrome. Therefore, some individuals might present different levels of metabolic syndrome. This study aims to identify two different severities of patients with metabolic syndrome-moderate versus severe-and the respective association of these severities with lifestyle habits and physical capacity. METHODS The sample included 2,281 adults aged between 19 and 85 years from the National Health and Nutrition Examination Survey (NHANES) study. Subjects were subcategorized into three groups: No metabolic syndrome, moderate metabolic syndrome, or severe metabolic syndrome. Physical activity and dietary habits were assessed by questionnaires. Cardiorespiratory fitness (CRF) was measured in adults aged <50 years, whereas physical capacity was measured in adults ≥50 years of age. RESULTS Thirty-eight percent of subjects had metabolic syndrome. From those, 15.3% had severe metabolic syndrome. No difference was observed among groups for energy intake. Subjects aged <50 years having severe metabolic syndrome had a lower CRF compared with moderate metabolic syndrome, whereas subjects ≥50 years reported less vigorous exercise (P≤0.05). Finally, subjects aged ≥50 years old having severe metabolic syndrome reported more physical incapacity compared to the other groups. CONCLUSION This study confirms that metabolic syndrome is a heterogeneous condition that may be subclassified. Severe metabolic syndrome is associated with lower physical capacity and CRF compared to moderate metabolic syndrome. Studies are needed to determine if metabolic syndrome categorization can be useful for clinical practice.

Correlation between the rate of weight loss and changes in body composition in obese postmenopausal women after 5 weeks: a pilot study.

Approximately 25% of weight lost during restrictive diets (without exercise) is lean body mass (LBM). No study has yet investigated the impact of the rate of weight loss (RWL) on LBM and fat mass (FM). The purpose of this study was to investigate the relationships between the RWL and body composition in older obese women. Twenty obese postmenopausal women aged between 51 and 74 years enrolled in a 5 week dietary weight loss intervention. Subjects were characterized according to their RWL (low RWL < 0.74 kg.week(-1) (n = 9) vs. high RWL > or = 0.74 kg.week(-1) (n = 11)). Total and trunk FM and LBM (by dual-energy X-ray absorptiometry) were measured before and after weight loss. A significant correlation was observed between the RWL (kg.week(-1)) and changes in LBM (kg.week(-1)) (r = 0.75; p = 0.0002). However, no association was observed with changes in FM (kg.week(-1)) (r = 0.40; p = 0.08). Both groups showed a similar decrease in FM (low RWL, -2.7 +/- 0.9 kg,; high RWL, -3.2 +/- 0.8 kg; p = 0.38), whereas losses in LBM were significantly higher in the high RWL than in the low RWL group (-1.6 +/- 1.2 kg vs. -0.4 +/- 1.1 kg; p = 0.05). An RWL > 0.74 kg.week(-1) was associated with a greater loss of LBM, but had no extra benefits on FM after a 5 week weight loss program. Current guidelines, which recommend RWL up to 0.91 kg.week(-1), might not be optimal to prevent decreases in LBM in postmenopausal women when no exercise is added.

Independent and combined effect of diet and exercise in adults with prediabetes

Prediabetes is defined as impaired fasting glucose and/or impaired glucose tolerance. Impaired fasting glucose is usually defined as fasting blood glucose between 5.6 mmol/L and 6.9 mmol/L (100.8–124.2 mg/dL), and impaired glucose tolerance is the 2-hour oral glucose tolerance test of 7.8–11.0 mmol/L (140.4–198.0 mg/dL). Most individuals with prediabetes are overweight or obese and are at greater risk of type 2 diabetes (T2D). The first line of treatment for individuals with prediabetes is lifestyle modification, including diet and exercise. The aim of this review, through the revision of primarily randomized control trials, is to discuss the independent and combined effect of diet and exercise on the incidence of T2D, glycemic control, and weight loss in adults with prediabetes. Based on the available literature, lifestyle modification combining both diet and exercise is effective at reducing the incidence of T2D and improving glycemic control, even without a significant reduction in body weight. Thus, it is unclear whether weight loss, through lifestyle modification, is a cornerstone for improving glycemic control in individuals with prediabetes. The independent effect of diet or exercise alone on the improvement in glycemic control and/or reduction in body weight in individuals with prediabetes still requires more studies to draw a clear conclusion, considering the quality and quantity of available studies. As of now, the best diet and/or exercise program to improve glycemic control and body weight in adults with prediabetes is unknown.

Walking Cadence to Exercise at Moderate Intensity for Adults: A Systematic Review

Background. Most adults choose walking as a leisure activity. However, many do not reach the international physical activity guidelines for adults, which recommend moderate intensity aerobic activity for at least 150 minutes/week in bouts of 10 minutes. Purpose. This systematic review provides an update on the walking cadence required to reach moderate intensity in adults and older adults, identifies variables associated with reaching moderate intensity, and evaluates how walking cadence intensity should be measured, but the main purpose is to report the interventions that have been attempted to prescribe walking cadence to increase time spent at moderate intensity or other outcomes for adults and older adults. Methods. SportDISCUS, Scopus, and PubMed databases were searched. We identified 3,917 articles and 31 were retained for this systematic review. Only articles written in English were included. Results. In general, 100 steps/minute is prescribed for adults to achieve moderate intensity, but older adults may require a higher cadence. Currently, few studies have explored using walking cadence prescription as an intervention to increase physical activity levels. Conclusion. Prescribing walking cadence as a way to increase physical activity levels has potential as a practical and useful strategy, but more evidence is required to assess its ability to increase physical activity levels at moderate intensity.