Effect of high intensity circuit training on muscle mass, muscular strength, and blood parameters in sedentary workers.

Background: The study aim was to investigate the effect of high intensity circuit training on body composition, muscular performance, and blood parameters in sedentary workers. Methods: A total of 36 middle-aged sedentary female workers were randomly divided into high intensity circuit training (HICT) group, aerobic training (AT) group, and control (CON) group. The exercise training groups performed exercise three times per week for 8 weeks. In HICT, each session was 20-35 min with 2-3 rounds. Rounds were 8 min; the interval between rounds was 4-5 min. In AT, each exercise session comprised 20-35 min of aerobic dance training. Physiological parameters were measured 1 week before and after the interventions. The resulting data were analyzed using two-way mixed design ANOVA, the differences in body composition, muscular performance and blood parameters before and after training were compared. Results: The muscle mass (pre-test: 21.19 ± 2.47 kg; post-test: 21.69 ± 2.46 kg, p < 0.05) and knee extension 60°/s (pre-test: 82.10 ± 22.26 Nm/kg; post-test: 83.47 ± 12.83 Nm/kg, p < 0.05) of HICT group were significantly improved, with knee extension 60°/s significantly higher than that of the CON group (HICT: 83.47 ± 12.83 Nm/kg; CON: 71.09 ± 26.53 Nm/kg). In the AT group, body weight (BW) decreased significantly (Pre-test: 59.37 ± 8.24 kg; Post-test: 58.94 ± 7.98 kg); no significant change was observed in CON group. The groups exhibited no significant change in blood parameters (hs-CRP, TC, and LDL-C) or IGF-1. Conclusions: Sedentary worker's muscle mass and lower-limb muscular performance were effectively improved by performing 8-week HICT with the benefits of short duration, no spatial constraints, and using one's BW, whereas AT caused a significant decrease in BW. However, the AT induced decrease in BW was probably an effect of muscle loss rather than exercise-induced weight loss.

Association of Regular Leisure-Time Physical Activity with Self-Reported Body Mass Index and Obesity Risk among Middle-Aged and Older Adults in Taiwan.

Through this study, we aimed to determine the association of regular leisure-time physical activity (LTPA) with self-reported body mass index (BMI) and obesity risk among middle-aged and older adults in Taiwan. We conducted a cross-sectional study and reviewed the data derived from the Taiwan National Physical Activity Survey (TNPAS). Responses from 12,687 participants aged 45-108 years from the database were collected in this study. All the participants completed a standardized structured questionnaire that solicitated information regarding their demographic characteristics (age, gender, education, occupation, and self-reported health status), physical activity behaviors (regular/nonregular LTPA), and self-reported anthropometrics (height, weight, and BMI). Multiple linear and logistic regressions were used to examine the association between regular LTPA and BMI, and between regular LTPA and obesity status, respectively. Regular LTPA was associated with male gender, normal weight, excellent or good self-reported health status, and a lower rate of being underweight compared with nonregular LTPA. Regular LTPA was significant negatively associated with being underweight (OR = 0.71, p < 0.05), whereas it had no significant relationship with BMI and obesity (p > 0.05). Regular LTPA was associated with a reduced risk of being underweight among middle-aged and elderly adults in Taiwan. Further research on the relevant mechanism underlying this phenomenon is warranted.

Development and Validation of 3 Min Incremental Step-In-Place Test for Predicting Maximal Oxygen Uptake in Home Settings: A Submaximal Exercise Study to Assess Cardiorespiratory Fitness.

The purpose of this research was to develop the 3 min incremental step-in-place (3MISP) test for predicting maximal oxygen uptake (V.O2max). A total of 205 adults (20-64 years) completed the 3MISP and V.O2max tests. Using age, gender, body composition (BC) including percent body fat (PBF) or body mass index (BMI), and with or without heart rate (HR) at the beginning of exercise (HR0) or difference between HR at the third minute during the exercise and the first minute post exercise (ΔHR3 - HR4) in the 3MISP test, six V.O2max prediction models were derived from multiple linear regression. Age (r = -0.239), gender (r = 0.430), BMI (r = -0.191), PBF (r = -0.706), HR0 (r = -0.516), and ΔHR3 - HR4 (r = 0.563) were significantly correlated to V.O2max. Among the six V.O2max prediction models, the PBF model∆HR3 - HR4 has the highest accuracy. The simplest models with age, gender, and PBF/BMI explained 54.5% of the V.O2max in the PBF modelBC and 39.8% of that in the BMI modelBC. The addition of HR0 and ∆HR3 - HR4 increases the variance of V.O2max explained by the PBF and BMI models∆HR3 - HR4 by 17.98% and 45.23%, respectively, while standard errors of estimate decrease by 10.73% and 15.61%. These data demonstrate that the models established using 3MISP-HR data can enhance the accuracy of V.O2max prediction.

Predicting maximal oxygen uptake from a 3-minute progressive knee-ups and step test.

BACKGROUND: Cardiorespiratory fitness assessment is crucial for diagnosing health risks and assessing interventions. Direct measurement of maximum oxygen uptake (V̇O2 max) yields more objective and accurate results, but it is practical only in a laboratory setting. We therefore investigated whether a 3-min progressive knee-up and step (3MPKS) test can be used to estimate peak oxygen uptake in these settings. METHOD: The data of 166 healthy adult participants were analyzed. We conducted a V̇O2 max test and a subsequent 3MPKS exercise test, in a balanced order, a week later. In a multivariate regression model, sex; age; relative V̇O2 max; body mass index (BMI); body fat percentage (BF); resting heart rate (HR0); and heart rates at the beginning as well as at the first, second, third, and fourth minutes (denoted by HR0, HR1, HR2, HR3, and HR4, respectively) during a step test were used as predictors. Moreover, R2 and standard error of estimate (SEE) were used to evaluate the accuracy of various body composition models in predicting V̇O2max. RESULTS: The predicted and actual V̇O2 max values were significantly correlated (BF% model: R2 = 0.624, SEE = 4.982; BMI model: R2 = 0.567, SEE = 5.153). The BF% model yielded more accurate predictions, and the model predictors were sex, age, BF%, HR0, ΔHR3-HR0, and ΔHR3-HR4. CONCLUSION: In our study, involving Taiwanese adults, we constructed and verified a model to predict V̇O2 max, which indicates cardiorespiratory fitness. This model had the predictors sex, age, body composition, and heart rate changes during a step test. Our 3MPKS test has the potential to be widely used in epidemiological research to measure V̇O2 max and other health-related parameters.

Effects of 8-week kettlebell training on body composition, muscle strength, pulmonary function, and chronic low-grade inflammation in elderly women with sarcopenia.

OBJECTIVES: To examine the effect of kettlebell training on body composition, muscle strength, pulmonary function, and chronic low-grade inflammatory markers among elderly people with sarcopenia. DESIGN: Randomized controlled trial. SETTING: Community center and research center. PARTICIPANTS: A total of 33 elderly women with sarcopenia (aged 65-75 years) were recruited. INTERVENTION: The participants were randomly assigned to a kettlebell training (KT) group or a control (CON) group. The KT group received an 8-week training intervention involving 60-min sessions twice a week, whereas the CON group members continued their daily lifestyles without participating in any exercise training. Four weeks of detraining were organized to observe the retention effect of the training program on the KT group. MEASUREMENTS: The participants' body composition, muscle strength, pulmonary function, and chronic low-grade inflammatory markers were measured and analyzed before training (at Week 0, W0), after 8 weeks of training (at Week 8, W8), and after 4 weeks of detraining (at Week 12, W12). RESULTS: In the KT group, appendicular skeletal muscle mass (ASM) and the sarcopenia index measured at W8 and W12 were significantly higher than those at W0(p = .004; p = .005). At W8 and W12, the sarcopenia index was significantly higher in the KT group than the CON group(p = .020; p = .019). In the CON group, the skeletal muscle mass levels measured at W8 and W12 were significantly lower than that at W0(p = .029; p = .005), and the ASM and the sarcopenia index measured at W8 were significantly lower than those at W0(p = .037; p = .036). Additionally, the measured left handgrip strength(p = .006), back strength(p = .011; p = .018), and peak expiratory flow (PEF) (p = .008; p = .006) were significantly higher in the KT group than the CON group at W8 and W12. At W8, the measured right handgrip strength was significantly higher in the KT group than the CON group(p = .043). In the KT group, the back strength and PEF levels measured at W8 and W12 were significantly higher than those at W0(p = .000; p = .004), and the left and right handgrip strength levels at W8 were significantly higher than those at W0(p = .004; p = .013). By contrast, in the CON group, the left(p = .004; p = .006)and right(p = .002; p = .004)handgrip strength levels and PEF(p = .018; p = .012) measured at W8 and W12 were significantly lower than those at W0. Moreover, compared with the high-sensitivity C-reactive protein (hs-CRP) levels measured at W0, those measured at W8 and W12 were significantly lower in the KT group(p = .006; p = .013)but significantly higher in the CON group(p = .005; p = .009). There was no significant difference in hs-CRP, IL-6, TNF-α between the KT and CON group. CONCLUSION: For elderly people with sarcopenia, participating in kettlebell training significantly increases the sarcopenia index, grip strength, back strength, and PEF. In addition, the retention effect of the training program continued after 4 weeks of detraining.

Effects of Different Types of Exercise on Body Composition, Muscle Strength, and IGF-1 in the Elderly with Sarcopenic Obesity.

OBJECTIVES: To investigate the influence of resistance training (RT), aerobic training (AT), or combination training (CT) interventions on the body composition, muscle strength performance, and insulin-like growth factor 1 (IGF-1) of patients with sarcopenic obesity. DESIGN: Randomized controlled trial. SETTING: Community center and research center. PARTICIPANTS: Sixty men and women aged 65-75 with sarcopenic obesity. INTERVENTION: Participants were randomly assigned to RT, AT, CT, and control (CON) groups. After training twice a week for 8 weeks, the participants in each group ceased training for 4 weeks before being examined for the retention effects of the training interventions. MEASUREMENTS: The body composition, grip strength, maximum back extensor strength, maximum knee extensor muscle strength, and blood IGF-1 concentration were measured. RESULTS: The skeletal muscle mass (SMM), body fat mass, appendicular SMM/weight %, and visceral fat area (VFA) of the RT, AT, and CT groups were significantly superior to those of the CON group at both week 8 and week 12. Regarding muscle strength performance, the RT group exhibited greater grip strength at weeks 8 and 12 as well as higher knee extensor performance at week 8 than that of the other groups. At week 8, the serum IGF-1 concentration of the RT group was higher than the CON group, whereas the CT group was superior to the AT and CON groups. CONCLUSION: Older adults with sarcopenic obesity who engaged in the RT, AT, and CT interventions demonstrated increased muscle mass and reduced total fat mass and VFA compared with those without training. The muscle strength performance and serum IGF-1 level in trained groups, especially in the RT group, were superior to the control group.