Jessica L. Unick

The acute effects of static and ballistic stretching on vertical jump performance in trained women.

Traditionally stretching has been included as part of a warm-up that precedes athletic participation. However, there is mixed evidence as to whether stretching actually enhances or hinders athletic performance. Therefore, the purpose of this study was to examine the acute effects of static (SS) and ballistic stretching (BS) on vertical jump (VJ) performance and to investigate whether power was altered at 15 and 30 minutes after stretching. Sixteen actively trained women performed a series of vertical jumps (countermovement and drop jumps) after an initial nonstretching (NS) session and after participating in BS and SS sessions that were conducted in a balanced and randomized order. The results indicated that there was no significant difference (p < 0.05) in VJ scores as a result of static or ballistic stretching, elapsed time, or initial flexibility scores. This suggests that stretching prior to competition may not negatively affect the performance of trained women.

Effectiveness of Lifestyle Interventions for Individuals With Severe Obesity and Type 2 Diabetes Results from the Look AHEAD trial

OBJECTIVE Rates of severe obesity (BMI ≥40 kg/m2) are on the rise, and effective treatment options are needed. We examined the effect of an intensive lifestyle intervention (ILI) on weight loss, cardiovascular disease (CVD) risk, and program adherence in participants with type 2 diabetes who were severely obese compared with overweight (BMI 25 to <30 kg/m2), class I (BMI 30 to <35 kg/m2), and class II (BMI 35 to <40 kg/m2) obese participants. RESEARCH DESIGN AND METHODS Participants in the Action for Health in Diabetes (Look AHEAD) trial were randomly assigned to ILI or diabetes support and education (DSE). DSE participants received a less intense educational intervention, whereas ILI participants received an intensive behavioral treatment to increase physical activity (PA) and reduce caloric intake. This article focuses on the 2,503 ILI participants (age 58.6 ± 6.8 years). RESULTS At 1 year, severely obese participants in the ILI group lost −9.04 ± 7.6% of initial body weight, which was significantly greater (P < 0.05) than ILI participants who were overweight (−7.43 ± 5.6%) and comparable to class I (−8.72 ± 6.4%) and class II obese (−8.64 ± 7.4%) participants. All BMI groups had comparable improvements in fitness, PA, LDL cholesterol, triglycerides, blood pressure, fasting glucose, and HbA1c at 1 year. ILI treatment session attendance was excellent and did not differ among weight categories (severe obese 80% vs. others 83%; P = 0.43). CONCLUSIONS Severely obese participants in the ILI group had similar adherence, percentage of weight loss, and improvement in CVD risk compared with less obese participants. Behavioral weight loss programs should be considered an effective option for this population.

Pre‐ to Postoperative Physical Activity Changes in Bariatric Surgery Patients: Self Report vs. Objective Measures

Bariatric surgery patients report significant pre‐ to postoperative increases in physical activity (PA). However, it is unclear whether objective measures would corroborate these changes. The present study compared self‐reported and accelerometer‐based estimates of changes in moderate‐to‐vigorous intensity PA (MVPA) from pre‐ (pre‐op) to 6 months postsurgery (post‐op). Twenty bariatric surgery (65% laparoscopic‐adjustable gastric banding, 35% gastric bypass) patients (46.2 ± 9.8 years, 88% female, pre‐op BMI = 50.8 ± 9.7 kg/m2) wore RT3 accelerometers as an objective measure of MVPA and completed the Paffenbarger Physical Activity Questionnaire (PPAQ) as a subjective measure before and 6 months after bariatric surgery. Time (min/week) spent in MVPA was calculated for the PPAQ and RT3 (≥1‐min and ≥10‐min bouts) at pre‐op and post‐op. Self‐reported MVPA increased fivefold from pre‐op to post‐op (44.6 ± 80.8 to 212.3 ± 212.4 min/week; P < 0.005). By contrast, the RT3 showed nonsignificant decreases in MVPA for both ≥1‐min (186.0 ± 169.0 to 151.2 ± 118.3 min/week) and ≥10‐min (41.3 ± 109.3 to 39.8 ± 71.3 min/week) bouts. At pre‐op, the percentage of participants who accumulated ≥150‐min/week of MVPA in bouts ≥10‐min according to the PPAQ and RT3 was identical (10%). However, at post‐op, 55% of participants reported compliance with the recommendation compared to 5% based on RT3 measurement (P = 0.002). Objectively‐measured changes in MVPA from pre‐op to 6 months post‐op appear to be much smaller than self‐reported changes. Further research involving larger samples is needed to confirm these findings and to determine whether self‐report and objective PA measures are differentially associated with surgical weight loss outcomes.

The long-term effectiveness of a lifestyle intervention in severely obese individuals.

OBJECTIVE Severe obesity (body mass index [BMI] ≥40 kg/m(2)) is a serious public health concern. Although bariatric surgery is an efficacious treatment approach, it is limited in reach; thus, nonsurgical treatment alternatives are needed. We examined the 4-year effects of an intensive lifestyle intervention on body weight and cardiovascular disease risk factors among severely obese, compared with overweight (25 ≤BMI <30), class I (30 ≤BMI <35), and class II obese (35 ≤BMI <40) participants. METHODS There were 5145 individuals with type 2 diabetes (45-76 years, BMI ≥25 kg/m(2)) randomized to an intensive lifestyle intervention or diabetes support and education. The lifestyle intervention group received a behavioral weight loss program that included group and individual meetings, a ≥10% weight loss goal, calorie restriction, and increased physical activity. Diabetes support and education received a less intense educational intervention. Four-year changes in body weight and cardiovascular disease risk factors were assessed. RESULTS Across BMI categories, 4-year changes in body weight were significantly greater in lifestyle participants compared with diabetes support and education (Ps <.05). At year 4, severely obese lifestyle participants lost 4.9%±8.5%, which was similar to class I (4.8%±7.2%) and class II obese participants (4.4%±7.6%), and significantly greater than overweight participants (3.4%±7.0%; P <.05). Four-year changes in low-density-lipoprotein cholesterol, triglycerides, diastolic blood pressure, HbA(1c), and blood glucose were similar across BMI categories in lifestyle participants; however, the severely obese had less favorable improvements in high-density-lipoprotein cholesterol (3.1±0.4 mg/dL) and systolic blood pressure (-1.4±0.7 mm Hg) compared with the less obese (Ps <.05). CONCLUSION Lifestyle interventions can result in important long-term weight losses and improvements in cardiovascular disease risk factors among a significant proportion of severely obese individuals.

Acute effect of walking on energy intake in overweight/obese women.

This study examined the acute effect of a bout of walking on hunger, energy intake, and appetite-regulating hormones [acylated ghrelin and glucagon-like peptide-1 (GLP-1)] in 19 overweight/obese women (BMI: 32.5 ± 4.3 kg/m²). Subjects underwent two experimental testing sessions in a counterbalanced order: exercise and rest. Subjects walked at a moderate-intensity for approximately 40 min or rested for a similar duration. Subjective feelings of hunger were assessed and blood was drawn at 5-time points (pre-, post-, 30-, 60-, 120-min post-testing). Ad libitum energy intake consumed 1-2h post-exercise/rest was assessed and similar between conditions (mean ± standard deviation; exercise: 551.5 ± 245.1 kcal [2.31 ± 1.0 MJ] vs. rest: 548.7 ± 286.9 kcal [2.29 ± 1.2 MJ]). However, when considering the energy cost of exercise, relative energy intake was significantly lower following exercise (197.8 ± 256.5 kcal [0.83 ± 1.1 MJ]) compared to rest (504.3 ± 290.1 kcal [2.11 ± 1.2 MJ]). GLP-1 was lower in the exercise vs. resting condition while acylated ghrelin and hunger were unaltered by exercise. None of these variables were associated with energy intake. In conclusion, hunger and energy intake were unaltered by a bout of walking suggesting that overweight/obese individuals do not acutely compensate for the energy cost of the exercise bout through increased caloric consumption. This allows for an energy deficit to persist post-exercise, having potentially favorable implications for weight control.

Weight change in the first 2 months of a lifestyle intervention predicts weight changes 8 years later

Examine the relationship between 1‐ and 2‐month weight loss (WL) and 8‐year WL among participants enrolled in a lifestyle intervention.

Evaluation of early weight loss thresholds for identifying nonresponders to an intensive lifestyle intervention

Weight losses in lifestyle interventions are variable, yet prediction of long‐term success is difficult. The utility of using various weight loss thresholds in the first 2 months of treatment for predicting 1‐year outcomes was examined.

Contribution of behavior intervention components to 24-month weight loss.

UNLABELLED Sustaining weight loss at the long term is difficult. PURPOSE To examine if eating behaviors, physical activity levels, and program participation influence ones ability to achieve ≥5%, ≥7%, and ≥10% weight loss during a period of 24 months. METHODS Data from 170 overweight and obese women (body mass index = 32.7 ± 4.2 kg·m(-2)) were analyzed in this study. All women followed a standard 24-month behavioral weight loss program in which they were instructed to decrease caloric intake and increase physical activity levels. Eating behaviors, body weight, and physical activity levels were assessed at baseline and at 6 and 24 months. Program participation was evaluated by the percentage of group meetings attended and the percentage of telephone calls completed with an interventionist. Three separate stepwise linear regression analyses were performed to identify variables that were predictive of ≥5%, ≥7%, and ≥10% weight loss at 24 months. RESULTS The percentage of telephone calls completed and change in weight loss eating behaviors predicted ≥5% (r2 = 0.16), ≥7% (r2 = 0.14), and ≥10% weight loss (r2 = 0.10) at 24 months. However, the change in physical activity levels from baseline to 24 months was only predictive of weight losses ≥10% (r2 = 0.11). CONCLUSIONS Behavioral factors, such as adopting healthy eating behaviors and telephone contact time, are important components that assist individuals in achieving weight losses ≥5%. However, high levels of physical activity play a more prominent role in sustaining weight losses ≥10%. Therefore, innovative strategies to enhance long-term exercise adherence should be developed.

Self-reported and objectively measured sedentary behavior in bariatric surgery candidates.

BACKGROUND Sedentary behavior (SB), independent of physical activity, represents a significant health risk. We previously used objective measures to demonstrate that bariatric surgery candidates engage in high levels of SB overall, but supplementing these measures with subjective reports would provide information about time allocated to different forms of SB. The aim of this study was to examine self-reported time spent performing specific types of SB and discrepancy between self-reported and objectively measured estimates of total sedentary time in bariatric surgery candidates. METHODS A total of 52 bariatric surgery candidates (87% female; age = 46.2 ± 9.1 years; body mass index [BMI] = 45.3 ± 6.7) completed the 9-item Sedentary Behavior Questionnaire (SBQ) as a subjective measure of SB and wore the SenseWear Armband (SWA; SenseWear, Pittsburgh, PA) as an objective measure. Paired samples t tests and the intraclass correlation coefficient (ICC) assessed measurement discrepancy. RESULTS Television-viewing was the most frequently performed type of SB (2.7 ± 1.6 hours per day), followed by paper/computer work (1.9 ± 1.8 hours per day), driving/riding in automobile (1.2 ± 1.1 hours per day), and sitting/talking on telephone (1.1 ± 1.2 hours per day). On average, the SBQ and SWA produced similar estimates of daily sedentary time (hours per day) at the group level (9.6 ± 4.8 versus 9.3 ± 1.9; mean difference = -.34 ± 4.6; P = .59), although agreement between the measures at the individual level was poor (mean absolute value of difference = 3.8 ± 2.8 hours per day; ICC = .22; P = .06). CONCLUSION Television-viewing was the single SB in which participants most frequently engaged and thus may be an important modifiable target for reducing total sedentary time in bariatric surgery candidates. The SBQ and SWA can be used similarly to describe SB levels in this patient population at the group level; however, ability of these measures to produce comparable estimates of sedentary time for any individual patient is limited.

Association of weight loss maintenance and weight regain on 4-year changes in CVD risk factors: The action for health in diabetes (Look AHEAD) clinical trial

OBJECTIVE Short-term weight loss improves cardiovascular disease (CVD) risk factors. We sought to determine the longer-term effects of maintaining weight loss or, conversely, regaining weight. RESEARCH DESIGN AND METHODS We used data from Action for Health in Diabetes (Look AHEAD), a randomized trial of intensive lifestyle intervention (ILI) compared to a control condition in overweight/obese individuals with type 2 diabetes. ILI participants were grouped according to weight change patterns, as follows: 1) no weight loss (±3% at years 1 and 4); 2) moderate weight loss (3–8% at years 1 and 4); 3) large weight loss (8–20% at years 1 and 4); 4) moderate loss/full regain (3–8% at year 1/±3% at year 4); 5) large loss/full regain (8–20% at year 1/± 3% year 4); and 6) large loss/partial regain (8–20% at year 1/3–8% at year 4) and changes in CVD risk factors were compared. RESULTS Adjusting for baseline differences and medication use, larger weight losses produced greater improvements in HbA1c, systolic blood pressure, HDL cholesterol, and triglycerides at years 1 and 4 (all P ≤ 0.02). Despite maintenance of weight loss, HbA1c levels worsened between years 1 and 4, and remained below baseline only in those with large weight losses. We found no negative associations of losing and regaining weight relative to not having lost weight. Moreover, those who had large initial weight loss but full regain of weight had greater improvements in HbA1c levels at year 4 than those with smaller or no initial weight loss. CONCLUSIONS Larger initial weight loss should be encouraged in individuals with type 2 diabetes, despite the possibility of regain.