Lyndsey M. Hornbuckle

Effects of Static Stretching on Energy Cost and Running Endurance Performance

Wilson, JM, Hornbuckle, LM, Kim, J.-S, Ugrinowitsch, C, Lee, S.-R, Zourdos, MC, Sommer, B, and Panton, LB. Effects of static stretching on energy cost and running endurance performance. J Strength Cond Res 24(9): 2274-2279, 2010-Stretching before anaerobic events has resulted in declines in performance; however, the immediate effects of stretching on endurance performance have not been investigated. This study investigated the effects of static stretching on energy cost and endurance performance in trained male runners. Ten trained male distance runners aged 25 ± 7 years with an average &OV0312;O2max of 63.8 ± 2.8 ml/kg/min were recruited. Participants reported to the laboratory on 3 separate days. On day 1, anthropometrics and &OV0312;O2max were measured. On days 2 and 3, participants performed a 60-minute treadmill run randomly under stretching or nonstretching conditions separated by at least 1 week. Stretching consisted of 16 minutes of static stretching using 5 exercises for the major lower body muscle groups, whereas nonstretching consisted of 16 minutes of quiet sitting. The run consisted of a 30-minute 65% &OV0312;O2max preload followed by a 30-minute performance run where participants ran as far as possible without viewing distance or speed. Total calories expended were determined for the 30-minute preload run, whereas performance was measured as distance covered in the performance run. Performance was significantly greater in the nonstretching (6.0 ± 1.1 km) vs. the stretching (5.8 ± 1.0 km) condition (p < 0.05), with significantly greater energy expenditure during the stretching compared with the nonstretching condition (425 ± 50 vs. 405 ± 50 kcals). Our findings suggest that stretching before an endurance event may lower endurance performance and increase the energy cost of running.

Effects of Resistance Training and Chiropractic Treatment in Women with Fibromyalgia

OBJECTIVE The objective of this study was to evaluate resistance training (RES) and RES combined with chiropractic treatment (RES-C) on fibromyalgia (FM) impact and functionality in women with FM. DESIGN The design of the study was a randomized control trial. SETTING Testing and training were completed at the university and chiropractic treatment was completed at chiropractic clinics. PARTICIPANTS Participants (48 +/- 9 years; mean +/- standard deviation) were randomly assigned to RES (n = 10) or RES-C (n = 11). INTERVENTION Both groups completed 16 weeks of RES consisting of 10 exercises performed two times per week. RES-C received RES plus chiropractic treatment two times per week. OUTCOME MEASURES Strength was assessed using one repetition maximum for the chest press and leg extension. FM impact was measured using the FM impact questionnaire, myalgic score, and the number of active tender points. Functionality was assessed using the 10-item Continuous Scale Physical Functional Performance test. Analyses of variance with repeated measures compared groups before and after the intervention. RESULTS Six (6) participants discontinued the study: 5 from RES and 1 from RES-C. Adherence to training was significantly higher in RES-C (92.0 +/- 7.5%) than in RES (82.8 +/- 7.5%). Both groups increased (p < or = 0.05) upper and lower body strength. There were similar improvements in FM impact in both groups. There were no group interactions for the functionality measures. Both groups improved in the strength domains; however, only RES-C significantly improved in the pre- to postfunctional domains of flexibility, balance and coordination, and endurance. CONCLUSIONS In women with FM, resistance training improves strength, FM impact, and strength domains of functionality. The addition of chiropractic treatment improved adherence and dropout rates to the resistance training and facilitated greater improvements in the domains of functionality.

Effects of Resistance Training and Walking on Cardiovascular Disease Risk in African-American Women

PURPOSE The studys purpose was to evaluate the effects of walking (W) and walking plus resistance training (WRT) on cardiovascular disease risk factors in inactive middle-aged (49.0 ± 5.5 yr) African-American women (body mass index = 34.7 ± 6.4 kg·m(-2)). METHODS Body composition, blood pressure, HDL cholesterol, triglycerides, glycosylated hemoglobin (HbA1c), C-reactive protein, and fibrinogen were measured before and after a 12-wk exercise intervention. Subjects were randomly assigned to one of two training groups. The W group (n = 25) was instructed to increase daily pedometer-measured walking to ≥10,000 steps per day, whereas the WRT group (n = 19) was given the same walking prescription plus supervised resistance training 2 d·wk(-1). A two-way repeated-measures ANOVA with an intention-to-treat analysis was performed to examine changes between groups. Significance was accepted at P ≤ 0.05. RESULTS Both groups significantly (P < 0.001) increased walking (W = 5453 ± 2119 to 6845 ± 2279 steps per day, WRT = 4823 ± 1758 to 6859 ± 2012 steps per day). WRT significantly (P < 0.001) increased both upper (100 ± 15 to 113 ± 18 kg) and lower (102 ± 20 to 116 ± 25 kg) body strength compared with W. WRT significantly decreased waist circumference (94.8 ± 12.3 to 92.9 ± 12.0 cm, P = 0.021) and total fat mass (42.6 ± 11.1 to 41.8 ± 10.8 kg, P = 0.036) compared with W. WRT also significantly decreased pre- to postintervention body fat (45.8% ± 6.2% to 45.3% ± 6.2%, P = 0.018), HbA1c (5.9% ± 1.2% to 5.6% ± 1.0%, P = 0.028), and mean glucose calculated from HbA1c (122 ± 39 to 114 ± 32 mg·dL(-1), P = 0.028), whereas W showed no changes. Blood pressure, HDL cholesterol, triglycerides, and C-reactive protein were not affected by either intervention. CONCLUSIONS Although both interventions increased steps per day, WRT was more effective in improving several body composition measures and glucose control in 12 wk. WRT may be an important addition to a lifestyle intervention aiming to facilitate reductions in cardiovascular disease risk factors in overweight and obese African-American women.

Evidence for the Association between Abdominal Fat and Cardiovascular Risk Factors in Overweight and Obese African American Women

Objective: To determine the association between total body fat and abdominal region fat derived from dual-energy x-ray absorptiometry (DXA) scans and cardiovascular disease (CVD) risk factors in middle- to older-aged African American (AA) women. We also compared tape-measured waist and hip circumference and their ratio (WHR) with DXA measurements in the context of CVD risk factor predictability. Methods: Participants included 59 overweight or obese African American women (age, 48.7 ± 5.6 years). Anthropometries, including waist and hip circumferences, were measured, and DXA scans were used to derive fat mass from the total body and abdominal region. Blood analyses included glucose, total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, total cholesterol/HDL and LDL/HDL ratios, C-reactive protein (CRP), and fibrinogen. Multiple linear regression models were used to investigate the association among DXA-derived fat mass measures, waist circumference, WHR, and cardiovascular risk factors. Results: Among DXA-derived fat mass measures, DXA-derived abdominal fat mass showed the best prediction for glucose and triglycerides, although waist circumference and DXA-derived abdominal fat mass had equivalent capacity for predicting the total cholesterol/HDL ratio. Furthermore, waist circumference showed the best prediction for LDL/HDL ratio and CRP. Conclusions: Both DXA-derived abdominal fat mass and waist circumference had comparable capacity for predicting blood lipid profiles and CRP. Therefore, if waist circumference is measured correctly, it could be used as the simplest means of predicting CVD risk factors in overweight/obese AA women when DXA is not available.

Effect of ActiGraph's Low Frequency Extension for Estimating Steps and Physical Activity Intensity

This study examined the effects of the ActiGraph’s (AG) low-frequency extension (LFE) filter on steps and physical activity classification in the free-living environment. Thirty-four African-American women (age, 24.5±5.2 years; BMI, 24.9±4.5 kg/m2) had daily activity measured simultaneously with an AG-GT3X+ accelerometer and a New Lifestyles NL-800 pedometer for seven days. Steps per day (steps/day) and time (minutes/day) spent in sedentary, light, and moderate-to-vigorous physical activity (MVPA) were examined with and without the LFE filter (AG-LFE and AG-N, respectively). The AG-LFE recorded more total steps (13,723±4,983 steps/day) compared to AG-N and NL-800 (6,172±2,838 and 5,817±3,037 steps/day, respectively; p<0.001). Compared to the AG-N, the AG-LFE estimated less time in sedentary behaviors (518.7±92.1 vs. 504.2±105.4 min/day, respectively; p<0.001), and more time in light (247.7±70.4 vs. 279.1±74.7 min/day, respectively; p<0.001) and MVPA (18.9±16.9 vs. 21.5±18.2 min/day, respectively; p<0.001), respectively. These data suggest that steps and physical activity classifications will be affected when using the ActiGraph with and without the LFE filter. Future research should investigate the accuracy of these measures using the LFE filter.

Effects of a 12-Month Pedometer-Based Walking Intervention in Women of Low Socioeconomic Status.

This study examined the effects of a 12-month walking intervention in overweight/obese, low socioeconomic women. Forty-six women (48.2 ± 8.0 years) entered the study. Outcomes included weight, waist and hip circumferences, body mass index (BMI), blood pressure, glycosylated hemoglobin, blood lipids, fibrinogen, and high-sensitivity C-reactive protein (hsCRP). Both intention-to-treat analyses in all participants and group analyses in study completers only (3K group = increased steps/day by ≥3,000; No Δ group = did not increase steps/day by ≥3,000) were conducted. Group × time ANOVA was used. In study completers, 3K significantly increased steps/day (6,903 ± 3,328 to 12,323 ± 5,736) compared to No Δ (4,926 ± 3,374 to 5,174 ± 3,095) from baseline to 12 months. There was a significant time effect for weight (P = 0.030), BMI (P = 0.029), and hsCRP (P = 0.044). Low socioeconomic women who adhere to a long-term, pedometer-based walking intervention significantly increased steps/day and may improve body weight, BMI, and hsCRP. This could help reduce health disparities in this population over time.