Kleverton Krinski

Psychophysiological Responses to Self-Paced Treadmill and Overground Exercise

UNLABELLED Speculation exists that a positive affective response experienced during exercise may play an important role in predicting exercise adherence. Previous studies using self-paced exercise protocols have been associated with health benefits and pleasant experiences. However, all of these studies were conducted in laboratories, and consequently, the external validity of the findings may be questionable. PURPOSE To determine whether environmental settings (treadmill vs overground) differentially influence physiological, perceptual, and affective responses to exercise at a self-selected pace. METHODS Thirty-four individuals (17 men and 17 women) between 18 and 30 yr volunteered to participate in this study. During the orientation session, individuals underwent an initial screening, anthropometric measurements, and familiarization with the experimental procedures. Next, subjects underwent a maximal treadmill test. In the two experimental trials, participants performed 20-min bouts of treadmill and overground walking at a self-selected pace, which were completed in a counterbalanced order. At least 48 h separated experimental trials. RESULTS Using repeated-measures ANOVA, overground walking speed was significantly faster than treadmill walking speed (P < 0.01) during the 20-min bout of self-paced exercise. However, exercise intensity (%VO2R and %HRR) and perceived exertion during the session of overground walking were significantly lower (P < 0.05) when compared with those during the treadmill session. In addition, affective valence was more positive during the session of overground walking than during the treadmill session (P < 0.01). CONCLUSIONS These data extend previous findings by showing that environmental setting influences physiological, perceptual, and affective responses during exercise at a self-selected pace. Self-paced exercise performed over ground resulted in lower perceptual and more positive affective responses.

Urinary incontinence and waist circumference in older women

OBJECTIVE the study aims to determine the association between adiposity and fitness with urinary incontinence (UI) in older women. METHODS a cross-sectional study was conducted in southern Brazil. A sample of 1,069 urban women, age 60+, was assessed for UI (in-person interview), adiposity (body mass index [BMI] and waist circumference [WC]) and fitness. Logistic regression models were developed to assess the association between UI and the independent variables-adiposity (BMI and WC) and fitness indicators. All models were adjusted for age, socioecomomic level, diabetes and hypertension. RESULTS BMI and functional tests were not significantly associated with UI. WC was an independent and significant predictor. Relative to women in the lowest quartile of WC, odds ratios for UI were 1.98 for WC of 79-86 cm, 2.07 for WC of 86-94 cm and 2.24 for WC >94 cm (P = 0.03). CONCLUSION central adiposity, as indicated by large WC, increases the risk of UI. Intra-abdominal pressure and its effect on urethral structures may be responsible for this increased risk. Older women should be counselled on the risk of central obesity for UI.

Feeling of pleasure to high-intensity interval exercise is dependent of the number of work bouts and physical activity status

Objectives To examine the affective responses during a single bout of a low-volume HIIE in active and insufficiently active men. Materials and methods Fifty-eight men (aged 25.3 ± 3.6 years) volunteered to participate in this study: i) active (n = 29) and ii) insufficiently active (n = 29). Each subject undertook i) initial screening and physical evaluation, ii) maximal exercise test, and iii) a single bout of a low-volume HIIE. The HIIE protocol consisted of 10 x 60s work bouts at 90% of maximal treadmill velocity (MTV) interspersed with 60s of active recovery at 30% of MTV. Affective responses (Feeling Scale, -5/+5), rating of perceived exertion (Borg’s RPE, 6–20), and heart rate (HR) were recorded during the last 10s of each work bout. A two-factor mixed-model repeated measures ANOVA, independent-samples t test, and chi-squared test were used to data analysis. Results There were similar positive affective responses to the first three work bouts between insufficiently active and active men (p > 0.05). However, insufficiently active group displayed lower affective responses over time (work bout 4 to 10) than the active group (p < 0.01). Also, the insufficiently active group displayed lower values of mean, lowest, and highest affective response, as well as lower values of affective response at the highest RPE than the active group (p < 0.001). There were no differences in the RPE and HR between the groups (p > 0.05). Conclusions Insufficiently active and active men report feelings of pleasure to few work bouts (i.e., 3–4) during low-volume HIIE, while the affective responses become more unpleasant over time for insufficiently active subjects. Investigations on the effects of low-volume HIIE protocols including a fewer number of work bouts on health status and fitness of less active subjects would be interesting, especially in the first training weeks.

The influence of adiposity on physiological, perceptual, and affective responses during walking at a self-selected pace.

The aim of this study was to investigate the influence of adiposity (%body fat) on physiological, perceptual, and affective responses during walking. 45 women were divided into low, medium, and high tertiles according to %body fat. Each participant completed a maximal exercise test and a 20-min. bout of walking at a self-selected pace. The preferred walking speed was similar among groups, whereas %VO2 max was greater in the high fertile group compared with the other two groups. Nevertheless, perceptual and affective responses were similar between the groups. These findings suggest that physiological responses relative to maximal capacity, but not perceptual and affective responses, of sedentary women are influenced by adiposity during walking at a self-selected pace. However, when the physiological responses are relative to ventilatory threshold, there are no differences between individuals with different levels of adiposity.

Is the Self-Selected Resistance Exercise Intensity by Older Women Consistent With the American College of Sports Medicine Guidelines to Improve Muscular Fitness?

Abstract Elsangedy, HM, Krause, MP, Krinski, K, Alves, RC, Hsin Nery Chao, C, and da Silva, SG. Is the self-selected resistance exercise intensity by older women consistent with the American College of Sports Medicine guidelines to improve muscular fitness? J Strength Cond Res 27(7): 1877–1884, 2013—The purpose of this study was to verify the self-selected intensity during resistance training (RT) in older women. Twenty healthy women (mean age, 65.6 years) underwent a 2-week familiarization period followed by 3 experimental sessions. During the first session, anthropometric measurements were taken. The second session involved completion of a 1 repetition maximum (1RM) test for the following exercises: chest press, leg press, lat pull-down, leg extension, lateral shoulder raise, leg curl, biceps curl, and triceps pushdown. Last, a single RT session was performed at a self-selected intensity. During the RT session, participants were instructed to self-select a load for performing 3 sets of 10–15 repetitions. Data were analyzed by mean (SD) and analysis of variance with repeated measures (p < 0.05). Global mean of the 3 sets was bench press 41.0% 1RM (11.9), leg press 43.0% 1RM (17.2), lat pull-down 47.2% 1RM (11.1), leg extension 33.0% 1RM (8.1), lateral shoulder raise 51.1% 1RM (12.1), leg curl 43.5% 1RM (8.8), biceps curl 48.0% 1RM (15.5), and triceps pushdown 51.7% 1RM (13.3); there were no significant differences between the sets (p > 0.05). These results indicate that inactive older women self-selected an intensity exercise during RT below the recommendation for improvements on muscle fitness in apparently healthy older adults. However, this intensity is recommended for very deconditioned individuals. Nevertheless, the use of self-selection strategy during an exercise program can have greater advantages because of its easy applicability, its positive relation with exercise adherence, and for promoting initial muscle conditioning in older adults. Furthermore, it is crucial to gradually increase the RT load to guarantee better and sustainable effects on muscle fitness. Finally, future studies are needed to establish the chronic effects of RT at self-selected intensity on muscle fitness and the functional health of older adults.

Gender-Based Differences in Substrate Use During Exercise at a Self-Selected Pace

Dasilva, SG, Guidetti, L, Buzzachera, CF, Elsangedy, HM, Krinski, K, De Campos, W, Goss, FL, and Baldari, C. Gender-based differences in substrate use during exercise at a self-selected pace. J Strength Cond Res 25(9): 2544-2551, 2011—The aim of this study was to investigate gender-based differences in substrate use during exercise at a self-selected pace. Seventeen men and 17 women performed a maximal exercise test and a 20-minute bout of self-paced treadmill walking to determine carbohydrate and fat oxidation rates. Gas exchange measurements were performed throughout the tests, and stoichiometric equations were used to calculate substrate oxidation rates. For each individual, a best-fit polynomial curve was constructed using fat oxidation rate (g·min−1) vs. exercise intensity (percentage of maximal oxygen uptake, % &OV0312;o2max). Each individual curve was used to obtain the following variables: maximal fat oxidation (MFO), the peak rate of fat oxidation measured over the entire range of exercise intensities; fatmax, the exercise intensity at which the MFO was observed; and fatmax zone, range of exercise intensities with fat oxidation rates within 10% of fat oxidation rates at fatmax. Although the MFO was similar between genders, fatmax was lower in men than in women. Similarly, the “low” and “high” borders of the fatmax zone were lower in men than in women. During exercise at a self-selected pace, carbohydrate oxidation rates were greater in men than in women, despite no gender-based differences in fat oxidation rates. However, fat oxidation contribution to total energy expenditure (EE) was greater in women than in men, despite no gender-based differences in the exercise intensity. In conclusion, although both genders self-selected a similar exercise intensity, the contribution of fat oxidation to EE is greater in women than in men. Interestingly, both genders self-selected an exercise intensity that falls within the fatmax zone.

Effect of Body Mass Index on Affect at Intensities Spanning the Ventilatory Threshold

The aim of this study was to compare acute affective responses at exercise intensities based on the ventilatory threshold between normal weight, overweight, and obese women. 66 sedentary women (22 in each Body Mass Index group) performed a maximal graded treadmill test to measure their maximal oxygen uptake and ventilatory thresholds. Affective valence was compared at intensities spanning the ventilatory threshold (below, at, and above threshold). Affective valence below ventilatory threshold did not differ among the Body Mass Index groups. The obese group had a lower affective response at ventilatory threshold and above ventilatory threshold than the normal weight and overweight groups; the latter two groups did not differ. The obese group had a lower affective response than the normal and overweight groups, which corresponds to a less pleasant experience. Exercise prescriptions for obese subjects targeting intensities below ventilatory threshold can provide a more pleasant experience and may facilitate exercise adherence.

Effect of unilateral and bilateral resistance exercise on maximal voluntary strength, total volume of load lifted, and perceptual and metabolic responses.

The present study investigated the effect of unilateral and bilateral resistance exercise (RE) on maximal voluntary strength, total volume of load lifted (TVLL), rating of perceived exertion (RPE) and blood lactate concentration of resistance-trained males. Twelve healthy men were assessed for the leg extension one-repetition maximum (1RM) strength using bilateral and unilateral contractions. Following this assessment, an RE session (3 sets of repetitions to failure) was conducted with bilateral and unilateral (both limbs) contractions using a load of 50% 1RM. The TVLL was calculated by the product of the number of repetitions and the load lifted per repetition. RPE and blood lactate were measured before, during and after each set. Session RPE was measured 30 minutes after RE sessions. There was a significant difference in the bilateral (120.0±11.9) and unilateral (135.0±20.2 kg) 1RM strength (p < 0.05). The TVLL was similar between both RE sessions. Although the repetitions decreased with each successive set, the total number of repetitions completed in the bilateral protocol (48) was superior to the unilateral (40) protocol (p < 0.05). In both bouts, RPE increased with each subsequent set whilst blood lactate increased after set 1 and thereafter remained stable (p < 0.05). The RPE and lactate responses were not significantly different between both sessions. In conclusion, a bilateral deficit in leg extension strength was confirmed, but the TVLL was similar between both RE sessions when exercising to voluntary fatigue. This outcome could be attributed to the number of repetitions completed in the unilateral RE bout. The equal TVLL would also explain the similar perceptual and metabolic responses across each RE session.

Prevalência de sobrepeso e obesidade geral e central em mulheres idosas da cidade de Curitiba, Paraná

OBJECTIVE: The objective of this study was to investigate the prevalence of general and central overweight and obesity in a representative sample of the population of elderly women living in Curitiba, Parana. METHODS: The experimental design of this study was observational, cross-sectional and descriptive. The variables body mass index and waist circumference were obtained to determine general and central overweight and obesity, respectively. Measurements of central tendency, variability, relative and absolute frequencies in each age group within the body mass index and waist circumference categories were verified. RESULTS: The sample consisted of 1069 women aged above 60 years (mean=69.5; standard deviation=6.1 years). In relation to body mass index, most of the subjects were classified as overweight (43.5%), followed by obese (34.0%) and normal (22.5%). On the other hand, obesity (45.1%) prevailed in relation to the categories for waist circumference, followed by overweight (33.1%) and normal (21.8%). Furthermore, general overweight and obesity decreased from the first to the last age group (-20.4% and -11.6%, respectively), while normal weight increased substantially (+75.3%). Similar results were verified in relation to central adiposity, where overweight and obesity decreased 14.3% and 8.3%, respectively. CONCLUSION: An elevated prevalence of general and central overweight and obesity was verified among elderly women from Curitiba, Parana, Brazil, regardless of age. Public health programs that aim to prevent and reduce excess body fat by intervening on dietary intake patterns and energy expenditure by recommending regular physical activity are necessary for this population.

Rating of Perceived Exertion and Affective Responses during Tai Chi Chuan

Ratings of perceived exertion (RPE) and affective responses were assessed during Tai Chi Chuan. A total of 16 women (M age = 61.2 yr., SD = 8.8) participated in this study. Individuals practiced Tai Chi Chuan three times / week during seven weeks, and were assessed session-by-session (21 Wu Tai Chi Chuan sessions) in three moments (15, 30, and 45 min.) using Borgs scale (CR 0–10) and the Feeling Scale (+5/–5). With regard to RPE, there was a difference between 15 and 30 min. and between 15 and 45 min. The same pattern of differences was observed for the affective response. The RPE during the seven weeks ranged from “fairly light” to “moderate” and the affective response from “good” to “very good.” Thus, Tai Chi Chuan was perceived as a low-moderate intensity and pleasurable (positive affect) exercise by middle-aged and elderly women.