Michele S. Olson

A survey of physicians' attitudes and practices related to exercise promotion

METHODS One hundred sixty-eight physicians responded to a survey to determine their attitudes and practices related to exercise and the development of exercise prescriptions. The mean age was 45.5 +/- 10.8 years, with the majority being male (86.7%). RESULTS The survey found that 48% of the physicians required an exercise history as part of their initial examination and 91% encouraged their patients to participate in regular exercise programs. Seventy percent of the physicians did not develop exercise prescriptions and only 23% were familiar with the American College of Sports Medicine guidelines related to the development of exercise prescriptions. Only a small number of physicians (3%) had ever taken a college-level course related to exercise physiology and the development of exercise programs. The majority (78%) felt that there was a definite need in medical school for a course related to the medical aspects of exercise. CONCLUSIONS Results of this investigation indicate that while physicians support exercise for health promotion and rehabilitation, greater emphasis needs to be placed on physician involvement in promoting and/or prescribing exercise.

Relationship between fire fighting suppression tasks and physical fitness

This investigation evaluated the relationship between physical fitness and performance of fire suppression tasks. The following mean +/- SD values were associated with 91 fire fighters: age 31.69 +/- 7.39 years, height 177.29 +/- 6.38 cm, weight 83.97 +/- 10.86 kg, % fat 13.78 +/- 4.31, fat free weight (FFW) 71.52 +/- 7.66 kg, pull-ups 9.03 +/- 4.79, push-ups 41.02 +/- 14.08, 1.5 mile run 737.60 +/- 108.11 s, sit and reach 32.00 +/- 8.5 cm, sit-ups 39.88 +/- 7.75, and total grip strength 116.75 +/- 17.67 kg. The physical performance assessment (PPA) consisted of the following: stair climb, hoist, forcible entry, hose advance, and victim rescue. Significant correlations (p < 0.01) were found between the PPA and the following: total grip strength (r = -0.54), FFW (r = -0.47), height (r = -0.40), pull-ups (r = -0.38), push-ups (r = -0.38), 1.5 mile run (r = 0.38), sit-ups (r = -0.32), weight (r = -0.30) and % fat (r = 0.30). Multiple regression analysis indicated that the best multiple predictor of PPA was the 1.5 mile run, FFW, and pull-ups, r = 0.73, p < 0.001. This investigation shows the importance of physical fitness as related to performance of fire suppression job tasks.

Voice problems and risk factors among aerobics instructors

Fifty female and four male aerobics instructors completed a questionnaire pertaining to vocal problems and variables that could indicate an increased risk for developing problems. The questions concerned teaching experience, physical data regarding instructional facilities, method of voice projection, music volume, history of illness, allergies, voice loss, hoarseness, smoking habits, and knowledge of vocal hygiene. The results showed that a significant number of instructors experienced partial or complete voice loss (44%) during and after instructing, as well as increased episodes of voice loss, hoarseness, and sore throat unrelated to illness since they began instructing. Significant variables associated with voice problems included sore throat and hoarseness following instruction, and shouting to cue the participants. It was also found that very few instructors in this study had any knowledge of vocal hygiene techniques.

Cardiovascular and metabolic costs of forward, backward, and lateral motion.

PURPOSE The purpose of this study was to compare the metabolic and cardiovascular responses of movement in forward (FM), backward (BM), and lateral (LM) directions. METHODS Thirteen athletes with the following characteristics (mean +/- SD) were evaluated: age 21+/-3 yr, height 172.0+/-9.0 cm, weight 62.92+/-9.05 kg, and VO2max 54.13+/-7.42 mL x kg(-1) x min(-1). Subjects were evaluated at 80.45 and 134.08 m x min(-1). A repeated measures ANOVA was used for statistical analysis (P < 0.05). RESULTS At 80.45 m x min(-1), the following respective VO2 mL x kg(-1) x min(-1) and heart rate (HR) beats x min(-1) responses were: FM = 12.42+/-2.29, 113+/-10; BM = 15.95+/-2.45, 132+/-16; and LM = 22.10+/-4.76, 140+/-15. Both VO2 and HR were significantly different between conditions: LM > BM > FM. At 134.08 m x min(-1), the following respective VO2 and HR responses were: FM = 27.15+/-2.51, 146+/-7; BM = 31.33+/-5.77, 168+/-11; and LM = 32.58+/-5.74, 169+/-10. At 134.08 m x min(-1) neither HR or VO2 were significantly different between LM or BM (LM, BM, > FM). Stride length and stride frequency were also significantly different between conditions. These results indicate the variation in the energy cost of FM, BM, and LM.

SELF-REPORTS ON THE EATING DISORDER INVENTORY BY FEMALE AEROBIC INSTRUCTORS

This study examined the possibility of earing disorders in 30 female aerobic dance instructors. All subjects completed a biographical questionnaire and the Eating Disorder Inventory. The results showed that the aerobic instructors yielded scores which were comparable to similarly aged female weight lifters but tended to be lower than those of women distance runners (also of similar age). Interestingly, 23% (n = 7) of the subjects reported a previous history of bulimia and 17% (n = 5) reported a previous history of anorexia. Thus, 40% of the instructors indicated a previous experience with eating disorders. Based on all 30 participants, the mean scores associated with Body Dissatisfaction, Drive for Thinness, Ineffectiveness, and Perfectionism were quite comparable to those previously established for anorexic groups. In addition, a relatively high percentage of the sample yielded scores which were actually greater than mean values associated with anorexia patients on nine of the 11 sub-scales. Based on these results, a number of the aerobic dance instructors possessed scores suggesting behaviors and attitudes consistent with female athletes whose sports emphasize leanness and comparable to those who have eating disorders.

SKINFOLD THICKNESS IS RELATED TO CARDIOVASCULAR AUTONOMIC CONTROL AS ASSESSED BY HEART RATE VARIABILITY AND HEART RATE RECOVERY

Esco, MR, Williford, HN, and Olson, MS. Skinfold thickness is related to cardiovascular autonomic control as assessed by heart rate variability and heart rate recovery. J Strength Cond Res 25(8): 2304-2310, 2011—The purpose of this study was to determine if heart rate recovery (HRR) and heart rate variability (HRV) are related to maximal aerobic fitness and selected body composition measurements. Fifty men (age = 21.9 ± 3.0 years, height = 180.8 ± 7.2 cm, weight = 80.4 ± 9.1 kg, volunteered to participate in this study. For each subject, body mass index (BMI), waist circumference (WC), and the sum of skinfolds across the chest, abdomen, and thigh regions (SUMSF) were recorded. Heart rate variability (HRV) was assessed during a 5-minute period while the subjects rested in a supine position. The following frequency domain parameters of HRV were recorded: normalized high-frequency power (HFnu), and low-frequency to high-frequency power ratio (LF:HF). To determine maximal aerobic fitness (i.e., &OV0312;O2max), each subject performed a maximal graded exercise test on a treadmill. Heart rate recovery was recorded 1 (HRR1) and 2 (HRR2) minutes during a cool-down period. Mean &OV0312;O2max and BMI for all the subjects were 49.5 ± 7.5 ml·kg−1·min−1 and 24.7 ± 2.2 kg·m−2, respectively. Although &OV0312;O2max, WC, and SUMSF was each significantly correlated to HRR and HRV, only SUMSF had a significant independent correlation to HRR1, HRR2, HFnu, LF:HF (p < 0.01). The results of the regression procedure showed that SUMSF accounted for the greatest variance in HRR1, HRR2, HFnu, and LF:HF (p < 0.01). The results of this study suggest that cardiovascular autonomic modulation is significantly related to maximal aerobic fitness and body composition. However, SUMSF appears to have the strongest independent relationship with HRR and HRV, compared to other body composition parameters and &OV0312;O2max.

Relationship of push-ups and sit-ups tests to selected anthropometric variables and performance results: a multiple regression study.

Esco, MR, Olson, MS, and Williford, H. Relationship of push-ups and sit-ups tests to selected anthropometric variables and performance results: a multiple regression study. J Strength Cond Res 22(6): 1862-1868, 2008-The purpose of this study was to explore whether selected anthropometric measures such as specific skinfold sites, along with weight, height, body mass index (BMI), waist and hip circumferences, and waist/hip ratio (WHR) were associated with sit-ups (SU) and push-ups (PU) performance, and to build a regression model for SU and PU tests. One hundred apparently healthy adults (40 men and 60 women) served as the subjects for test validation. The subjects performed 60-second SU and PU tests. The variables analyzed via multiple regression included weight, height, BMI, hip and waist circumferences, WHR, skinfolds at the abdomen (SFAB), thigh (SFTH), and subscapularis (SFSS), and sex. An additional cohort of 40 subjects (17 men and 23 women) was used to cross-validate the regression models. Validity was confirmed by correlation and paired t-tests. The regression analysis yielded a four-variable (PU, height, SFAB, and SFTH) multiple regression equation for estimating SU (R2 = 0.64, SEE = 7.5 repetitions). For PU, only SU was loaded into the regression equation (R2 = 0.43, SEE = 9.4 repetitions). Thus, the variables in the regression models accounted for 64% and 43% of the variation in SU and PU, respectively. The cross-validation sample elicited a high correlation for SU (r = 0.87) and PU (r = 0.79) scores. Moreover, paired-samples t-tests revealed that there were no significant differences between actual and predicted SU and PU scores. Therefore, this study shows that there are a number of selected, health-related anthropometric variables that account significantly for, and are predictive of, SU and PU tests.

The Accuracy of Hand-to-Hand Bioelectrical Impedance Analysis in Predicting Body Composition in College-Age Female Athletes

Esco, MR, Olson, MS, Williford, HN, Lizana, SN, and Russell, AR. The accuracy of hand-to-hand bioelectrical impedance analysis in predicting body composition in college-age female athletes. J Strength Cond Res 25(4): 1040-1045, 2011-The purpose of this investigation was to determine the accuracy of hand-to-hand bioelectrical impedance analysis (BIA) for estimating body composition in college-age female athletes using dual-energy X-ray absorptiometry (DEXA) as the criterion measure. Forty National Association for Intercollegiate Athletics college female athletes volunteered to participate in this study. For each participant, total body fat percentage (BF%) and fat-free mass (FFM) were obtained via BIA and DEXA. The mean BF% and FFM values obtained by BIA were compared with the criterion DEXA measure. The DEXA strongly correlated to the BIA for BF% (r = 0.74, R2 = 0.55, SEE = 3.60, and p < 0.01) and FFM (r = 0.84, R2 = 0.71, SEE = 2.45, p < 0.01). However, when compared with the DEXA, the mean values for BIA were significantly lower for BF% (DEXA = 27.6 ± 5.3%, BIA = 22.5 ± 3.5%, p < 0.01) and higher for FFM (DEXA = 47.2 ± 4.5 kg, BIA = 50.6 ± 4.6 kg, p < 0.01). The results of this investigation indicate that hand-to-hand BIA significantly underestimates BF% and overestimated FFM in college-age female athletes when compared with the criterion DEXA. Practitioners should use caution when analyzing body composition with hand-held BIA in a population of athletic women.

Is Low-Impact Aerobic Dance an Effective Cardiovascular Workout?

In brief: Ten women performed four different aerobic dance routines in a randomized crossover study to evaluate energy expenditure. The routines consisted of the following combinations: low intensity, low impact; high intensity, low impact; low intensity, high impact; and high intensity, high impact. The women warmed up for five minutes, then did a 20-minute routine. Metabolic measures were monitored by means of open circuit spirometry and heart rates measured by ECG. Statistical analyses showed that for both high and low intensities, the high-impact routines required a significantly greater energy expenditure, regardless of heart rate. Thus for low-impact dance to meet the minimum guidelines for exercise suggested by the American College of Sports Medicine, it should be performed at high intensity.

The relationship between selected body composition variables and muscular endurance in women.

The primary purpose of this study was to determine if muscular endurance is affected by referenced waist circumference groupings, independent of body mass and subcutaneous abdominal fat, in women. This study also explored whether selected body composition measures were associated with muscular endurance. Eighty-four women were measured for height, weight, body mass index (BMI), waist circumference (WC), and abdominal skinfold thickness (SFAB) and performed 60-s sit-ups (SU) and maximal push-ups (PU) tests. Mean differences in SU and PU scores were tested across three groups based on WC as follows: WCG1 < 70 cm; WCG2 between 70 and 89 cm; WCG3 ≥ 90 cm. There were no significant differences in SU and PU scores between WCG1 and WCG2. WCG3 had significantly lower SU and PU scores compared to the other groups. After adjusting for the influence of SFAB, BMI, and weight, the differences disappeared. The regression analysis revealed a two-variable (BMI and SFAB) model that accounted for the variation in SU performance. For PU, only BMI loaded into the regression model. The results of this study suggest that women with a WC ≥ 90 cm have decreased muscular endurance compared to their lower WC counterparts. This difference is related to higher body masses.