David R. Bryan

Resistance training and intra-abdominal adipose tissue in older men and women.

PURPOSE Little is known concerning the effects of resistance-exercise training (RT) on older adults intra-abdominal adipose tissue (IAAT). The purpose of this study was to determine the effects of RT on fat distribution in 12 women and 14 men, aged 61-77 yr. METHODS Computed tomography IAAT and abdominal subcutaneous adipose tissue (SAT), densitometry-determined body composition, one-repetition maximum (1-RM), and isometric strength were measured before and after 25 wk of RT. Training consisted of two sets of 10 repetitions at 65-80% of 1-RM, three times each week. RESULTS There were similar increases in strength for both the men and women. Women improved 22% and 38% in the isometric strength test and 1-RM test, respectively, whereas the men improved 21% and 36%, respectively. A significant increase in fat-free mass (FFM) was found for both men and women. However, there was a significant gender x time interaction, which indicated that men increased FFM more than women (2.8 kg vs 1.0 kg, respectively). Similar decreases in fat mass (FM) were found for the men (1.8 kg) and women (1.7 kg). However, women lost a significant amount of IAAT (131 to 116 cm2), whereas the men did not (143 to 152 cm2). Similarly, women also lost a significant amount of SAT (254 to 239 cm2), but men did not (165 to 165 cm2). CONCLUSION Despite similar decreases in FM after a 25-wk RT program, older women lost significant amounts of IAAT and SAT, whereas the older men did not.

Dietary Adherence During Weight Loss Predicts Weight Regain

This study examined the relationship between previous dietary adherence during a low‐calorie diet weight loss intervention and subsequent weight change during a 2‐year follow‐up for weight maintenance. One hundred and sixteen healthy, recently weight reduced (lost ∼12 kg, BMI 22–25 kg/m2) premenopausal women were studied. Dietary adherence was assessed by doubly labeled water (DLW) and body composition change. Comparisons were made between the upper and lower tertiles for previous dietary adherence and subsequent weight change at 1‐ and 2‐year follow‐up. Percent weight regained was significantly lower (30.9 ± 6.7% vs. 66.7 ± 9.4%; P < 0.05) in the upper compared to the lower adherence tertile for previous weight loss dietary adherence (49.9 ± 8.8% vs. 96.8 ± 12.8% P < 0.05) at 1‐ and 2‐year follow‐up, respectively. This difference was partly explained by increases in daily activity‐related energy expenditure (AEE) (+95 ± 45 kcal/day vs. −44 ± 42 kcal/day, P < 0.05) and lower daily energy intake (2,066 ± 71 kcal/day vs. 2,289 ± 62 kcal/day, P < 0.05) in the higher tertile for previous dietary adherence, compared to the lower. These findings suggest that higher adherence (i.e., higher tertile) to the previous low‐calorie diet predicts lower weight regain over 2‐year follow‐up for weight maintenance, which is explained by lower energy intake and higher physical activity. Finally, how well an individual adheres to a low‐calorie diet intervention during weight loss may be a useful tool for identifying individuals who are particularly vulnerable to subsequent weight regain.

Frequency of Combined Resistance and Aerobic Training in Older Women

Abstract Fisher, G, McCarthy, JP, Zuckerman, PA, Bryan, DR, Bickel, CS, and Hunter, GR. Frequency of combined resistance and aerobic training in older women. J Strength Cond Res 27(7): 1868–1876, 2013—The aim of this study was to determine the optimal frequency of combined aerobic and resistance training for improving muscular strength (MS), cardiovascular fitness (CF), and functional tasks (FTs) in women older than 60 years. Sixty-three women were randomly assigned to 1 of 3 exercise training groups. Group 1 performed 1 resistance exercise training (RET) and 1 aerobic exercise training (AET) session per week (AET/RET 1 × wk−1); group 2 performed 2 RET and 2 AET sessions per week (AET/RET 2 × wk−1); and group 3 performed 3 RET and 3 AET sessions per week (AET/RET 3 × wk−1). MS, CF, and FT measurements were made pretraining and 16 weeks posttraining. Repeated-measures analysis of variance indicated a significant time effect for changes in MS, CF, and FT, such that all improved after training. However, there were no significant training group or training group × time interactions. Sixteen weeks of combined AET/RET (1 × wk−1, 2 × wk−1, or 3 × wk−1) lead to significant improvements in MS, CF, exercise economy, and FT. However, there were no significant differences for MS, CF, or FT outcomes between groups.

Weight loss and exercise training effect on oxygen uptake and heart rate response to locomotion.

Abstract Hunter, GR, Fisher, G, David R. Bryan, DR, and Zuckerman, PA. Weight loss and exercise training effect on oxygen uptake and heart rate response to locomotion. J Strength Cond Res 26(5): 1366–1373, 2012—Effects of resistance and aerobic training on the ease of physical activity during and after weight loss are unknown. The purpose of the study was to determine what effect weight loss combined with either aerobic or resistance training has on the ease of locomotion (net V[Combining Dot Above]O2 and heart rate). It is hypothesized that exercise training will result in an increased ease, lowers heart rate during locomotion. Seventy-three overweight premenopausal women were assigned to diet and aerobic training, diet and resistance training, or diet only. Subjects were evaluated while overweight, after diet-induced weight loss (average, 12.5 kg loss), and 1 year after weight loss (5.5 kg regain). Submaximal walking, grade walking, stair climbing, and bike oxygen uptake and heart rate were measured at all time points. Weight loss diet was 800 kcal per day. Exercisers trained 3 times per week during weight loss and 2 times per week during 1-year follow-up. Resistance training increased strength, and aerobic training increased maximum oxygen uptake. Net submaximal oxygen uptake was not affected by weight loss or exercise training. However, heart rate during walking, stair climbing, and bicycling was reduced after weight loss. No significant differences in reduction in heart rate were observed among the 3 treatment groups for locomotion after weight loss. However, during 1-year follow-up, exercise training resulted in maintenance of lower submaximal heart rate, whereas nonexercisers increased heart rate during locomotion. Results suggest that moderately intense exercise is helpful in improving the ease of movement after weight loss. Exercise training may be helpful in increasing the participation in free-living physical activity.

IAAT, catecholamines, and parity in African-American and European-American women.

Objective: We have recently reported that parous European‐American (EA) women have disproportionately more intra‐abdominal adipose tissue (IAAT) than their nulliparous counterparts. Mediating mechanisms for IAAT accumulation remain unknown; however, some evidence suggests a possible catecholamine link. The objective of this study was to determine whether the IAAT‐parity relationship found in EA women exists in African‐American (AA) women and to determine whether catecholamines play a mediating role.

Effects of Calorie Restriction in Obese Older Adults: The CROSSROADS Randomized Controlled Trial.

Background We lack a comprehensive assessment of the risks and benefits of calorie restriction in older adults at high risk for cardiometabolic disease. Calorie restriction may reduce visceral adipose tissue (VAT) but also have negative effects on lean mass and quality of life. Methods We conducted a 52-week, randomized controlled trial involving 164 older adults with obesity taking at least one medication for hyperlipidemia, hypertension, or diabetes. Interventions included an exercise intervention alone (Exercise), or with diet modification and body weight maintenance (Maintenance), or with diet modification and energy restriction (Weight Loss). The primary outcome was change in VAT at 12 months. Secondary outcomes included cardiometabolic risk factors, functional status, and quality of life. Results A total of 148 participants had measured weight at 12 months. Despite loss of -1.6% ± 0.3% body fat and 4.1% ± 0.7% initial body weight, Weight Loss did not have statistically greater loss of VAT (-192.6 ± 185.2 cm3) or lean mass (-0.4 ± 0.3 kg) compared with Exercise (VAT = -21.9 ± 173.7 cm3; lean mass = 0.3 ± 0.3 kg). Quality of life improved in all groups with no differences between groups. No significant changes in physical function were observed. Weight Loss had significantly greater improvements in blood glucose (-8.3 ± 3.6 mg/dL, p < .05) and HDL-cholesterol (5.3 ± 1.9, p < .01) compared with Exercise. There were no group differences in the frequency of adverse events. Conclusions While moderate calorie restriction did not significantly decrease VAT in older adults at high risk for cardiometabolic disease, it did reduce total body fat and cardiometabolic risk factors without significantly more adverse events and lean mass loss.

Calorie Restriction in Overweight Seniors: Response of Older Adults to a Dieting Study: The CROSSROADS Randomized Controlled Clinical Trial

We conducted a study designed to evaluate whether the benefits of intentional weight loss exceed the potential risks in a group of community-dwelling obese older adults who were at increased risk for cardiometabolic disease. The CROSSROADS trial used a prospective randomized controlled design to compare the effects of changes in diet composition alone or combined with weight loss with an exercise only control intervention on body composition and adipose tissue deposition (Specific Aim #1: To compare the effects of changes in diet composition alone or combined with weight loss with an exercise only control intervention on body composition, namely visceral adipose tissue), cardiometabolic disease risk (Specific Aim #2: To compare the effects of a change in diet composition alone or combined with weight loss with an exercise only control intervention on cardiometabolic disease risk), and functional status and quality of life (Specific Aim #3: To compare the effects of a change in diet composition alone or combined with weight loss with an exercise only control intervention on functional status and quality of life). Participants were randomly assigned to one of three groups: Exercise Only (Control) Intervention, Exercise + Diet Quality + Weight Maintenance Intervention, or Exercise + Diet Quality + Weight Loss Intervention. CROSSROADS utilized a lifestyle intervention approach consisting of exercise, dietary, and behavioral components. The development and implementation of the CROSSROADS protocol, including a description of the methodology, detailing specific elements of the lifestyle intervention, assurances of treatment fidelity, and participant retention; outcome measures and adverse event monitoring; as well as unique data management features of the trial results, are presented in this article.

Racial Differences in Relative Skeletal Muscle Mass Loss During Diet-Induced Weight Loss in Women: Relative Skeletal Muscle Mass Loss

It is unclear whether there are race‐specific differences in the maintenance of skeletal muscle during energy restriction. Changes in relative skeletal muscle index (RSMI; limb lean tissue divided by height squared) were compared following (1) diet alone, (2) diet + aerobic training, or (3) diet + resistance training.

Exercise training and/or diet on reduction of intra-abdominal adipose tissue and risk factors for cardiovascular disease

Background/ObjectivesTo test the effects of weight loss with and without exercise training (aerobic or resistance) on intra-abdominal adipose tissue (IAAT) and risk factors for cardiovascular disease (CVD). Additionally, CVD risk factors was evaluated before and after weight loss using previously established IAAT cut-points.Subjects/MethodsOne hundred twenty-two overweight premenopausal women were randomly assigned to one of three groups: (1) diet only (Diet); (2) diet and aerobic training (Diet + AT); or (3) diet and resistance training (Diet + RT); until a BMI of < 25 kg/m2 was reached. Computerized tomography was used to measure IAAT and blood lipids were measured by assay. Evaluations were made before and after weight loss.ResultsThough no group-by-time effects were found after weight loss, we observed significant time effects for: IAAT (−38.0%, P < 0.001), total cholesterol (TC) (−2.2%, P = 0.008), low-density lipoprotein cholesterol (LDL-C) (−4.8%, P < 0.001), high-density lipoprotein cholesterol (HDL-C) (+20.2%, P < 0.001), triglycerides (−18.7%, P < 0.001), TC/HDL-C (−16.3%, P < 0.001), and LDL-C/HDL-C (−18.0%, P < 0.001). Following weight loss, 40.2% of all participants reduced IAAT to < 40 cm2 (IAAT associated with low CVD risk). Furthermore, only 2.5% of participants had an IAAT > 110 cm2 (IAAT associated with high CVD risk) after weight loss. We also observed that decreases of IAAT were associated with decreased CVD risk factors after weight loss independent of race, changes in %fat mass and changes in maximal oxygen uptake.ConclusionsCaloric restriction leading to significant weight loss with or without exercise training appears to be equally effective for reducing IAAT and CVD risk factors.

Physiological Effort in Submaximal Fitness Tests Predicts Weight Loss in Overweight and Obese Men with Prostate Cancer in a Weight Loss Trial

Background Obesity and weight gain after the diagnosis of prostate cancer are associated with an increased risk of prostate cancer recurrence and mortality; individualized plans to help prostate cancer survivors maintain or lose weight may be beneficial for recurrence risk reduction. Herein, we explore whether gains in cardiovascular fitness predict successful weight loss in men participating in a weight loss trial (NCT01886677). Methods Forty men were randomized to receive twice-weekly in-person and telephone-based guidance on calorie-restricted diets and aerobic exercise to promote ~0.91 kg/week weight loss, or wait-list control. Thirty-two men completed submaximal VO2 Treadmill Tests (TT), anthropometric measures and two 24-hour dietary recalls at baseline and follow-up. For this secondary analysis, study arms were combined and associations between baseline and longitudinal changes in physiological effort (PE, measured by heart rate during TT), predicted VO2max, caloric intake and weight loss were analyzed. Results Men lost 3.4 kg in 50 ± 23 days on the study. Multivariate linear regression indicated weight change was associated with change in PE at stage 2TT (Partial R = 0.635, p < 0.001), days on study (Partial R = −0.589, p = 0.002) and change in caloric intake (Partial R = 0.457, p = 0.019). Conclusions Untrained men experiencing elevated heart rates during stage 2TT at baseline were able to achieve greater weight loss over the study period; this association was strengthened by a decrease in PE at the same level from baseline to follow-up concomitant with reduced caloric intake. Therefore, for these middle-aged and older men with lower aerobic fitness, exercise appears to be a key factor in achieving higher degrees of weight loss.