Assessment of aerobic exercise capacity in obesity, which expression of oxygen uptake is the best?

Impact of aging on maximal oxygen uptake in female runners and sedentary controls

The present study aimed to compare V̇O2max (absolute, adjusted to total body mass, and adjusted to lean mass) in recreational runners and sedentary women < and > 50 yr and verify the effect of aging and physical activity level on the three types of V̇O2 max expression. The study included 147 women:85 runners (45.7 ± 14.1 yr) and 62 sedentary controls (48.8 ± 9.8 yr). They were subjected to cardiopulmonary exercise testing for V̇O2 max measurement and a body composition test by dual-emission X-ray absorptiometry system. V̇O2max were expressed as absolute values (L/min), relative to total body mass values (mL/kg/min), and relative to lean mass values (mL/kgLM/min). The two-way analysis of variance revealed a significant interaction [F(2,131) = 4.43, p < 0.001] and effects of age group [F(2,131) = 32.79, p < 0.001] and physical activity group [F(2,131) = 55.64, p < 0.001] on V̇O2max (mL/min). V̇O2max (mL/kg/min) and V̇O2 max (mL/kgLM/min) were significantly influenced by age and physical activity levels. The multiple regression model explains 76.2 % of the dependent variable V̇O2max (mL/kg/min), age (β = -0.335, t = -7.841, p < 0.001), and physical activity group (β = -0.784, t = -18.351, p < 0.001). In conclusion, female runners had higher V̇O2 max values than sedentary women at all ages, even though aging has a greater impact on V̇O2 max in the runners group. In addition to cardiorespiratory fitness, women's metabolic lean mass function, as measured by V̇O2max adjusted by lean mass, is significantly influenced by aging. Finally, physical activity has a greater impact on V̇O2 max levels than aging.

Maximal Oxygen Consumption Is Negatively Associated with Fat Mass in Facioscapulohumeral Dystrophy

Facioscapulohumeral dystrophy (FSHD) leads to progressive changes in body composition such as loss of muscle mass and increase in adiposity. In healthy subjects, anthropometric parameters are associated with the maximum volume of oxygen consumed per minute (VO2max), which is a health and function indicator in several populations of subjects, both healthy and pathological. Since VO2max can be difficult to test in patients with FSHD due to exercise intolerance, the identification of associated anthropometric parameters could provide new easily obtainable elements for the patients' clinical stratification. The aim of this study was to evaluate whether anthropometric and body composition parameters are associated with VO2max in patients with FSHD. A total of 22 subjects with a molecular genetics-based diagnosis of FSHD (6 females, 16 males, mean age of 35.18 years) were recruited for the study. VO2max was measured by cardiopulmonary exercise tests (CPETs) on a cycle ergometer, utilizing a step incremental technique (15 Watts (W) every 30 s). Weight (Kg) and height (m) were obtained and utilized to calculate body mass index (BMI). Body composition parameters (fat mass (FM), fat free mass (FFM), and body cell mass (BCM)) were obtained by bioelectrical impedance analysis (BIA). Significant negative associations were found between VO2max and FM (Spearman correlation coefficient (SCC) -0.712), BMI (SCC -0.673), age (SCC -0.480), and weight (SCC -0.634), unlike FFM and BCM. Our results indicate that FM, BMI, age, and body weight are negatively associated with VO2max in patients with FSHD. This evidence may help practitioners to better stratify patients with FSHD.

Similar maximal aerobic capacity but lower energy efficiency during low-to-moderate exercise in women with constitutional thinness: new results from the NUTRILEAN study

PURPOSE

Individuals with constitutional thinness have been presented with a lower muscular energy metabolism at the cellular level but their effective aerobic capacities and exercise-related energy efficiency remains unexplored. The present study compares maximal and sub-maximal aerobic capacities between subjects with constitutional thinness and age-matched normal-weight ones.

METHODS

Anthropometric measures, body composition (Dual-X-ray absorptiometry), physical activity and sedentary time (GT3x actigraphs), and maximal aerobic capacities (cyclingV ˙ O 2peak test) were assessed in 18 constitutionally thin (CT-body mass index < 17.5 kg m-2) and 17 normal-weight (NW-body mass index between 20 and 25 kg m-2) women. Energy efficiency was assessed during a submaximal cycling test and a walking exercise.

RESULTS

CT had a lower body mass and body mass index compared to NW. Absolute peak oxygen uptake and maximal aerobic power were lower in CT subjects compared to NW (ES: - 1.63 [- 2.40; - 0.86] and - 1.32 [- 2.05; - 0.58], p < 0.001).V ˙ O 2peak related to body mass was not different between groups. Gross and net efficiency (ES: - 0.78 [- 1.48; - 0.06], p = 0.03 and ES: - 0.73 [- 1.43; - 0.01], p = 0.05) were lower in CT compared to NW during the submaximal cycling exercise. The gross energy cost of walking related to body mass was lower in subjects with CT (ES: - 1.80 [- 2.60; - 0.97, p = 0.05), with no difference for the net one. Perceived exertion was similar between groups in responses to both submaximal exercises.

CONCLUSION

Constitutionally thin women do not show impaired aerobic capacities at moderate to maximal intensities despite lower energy efficiency while cycling and walking at low-to-moderate intensities.

Effects of 24-week Polarized Training vs. Threshold Training in Obese Male Adults

The combination of high volume of moderate-intensity continuous training with a low volume of high-intensity interval training improved body composition and physical capacities in individuals with obesity. However, polarized training (POL) has never been used in adult men with obesity. Thus, the purpose of this study was to investigate changes in body composition and physical capacities induced by a 24-week POL or threshold (THR) program in obese male adults. Twenty male patients (mean age 39.8±6.3 yrs; mean body mass index [BMI] 31.6±2.7 kg∙m-2) participated in this study (n: 10 POL, n: 10 THR). After 24-week, body mass (BM) and fat mass (FM) decreased by -3.20±3.10 kg (P<0.05) and -3.80±2.80 kg (P<0.05), respectively, similarly in both groups. Maximal oxygen uptake (  ̇VO2max) and   ̇VO2 at respiratory compensation point (RCP) increased in the POL group (+8.5±12.2 and+9.0±17.0%, P<0.05) and in the THR group (+4.24±8.64 and+4.0±6.70%, P<0.05), as well   ̇VO2 at gas exchange threshold (GET) increased similarly in both groups (+12.8±12.0%, P<0.05). POL and THR were equally effective in improving body composition and physical capacities in obese subjects. Future studies are needed to determine whether adherence to the training program can be improved by adding a running competition compared with a group without competition at the end of the training program.

"Impact of aging on maximal oxygen uptake adjusted for lower limb lean mass, total body mass, and absolute values in runners"

Performance in endurance sports decreases with aging, which has been primarily attributed to cardiovascular and musculoskeletal aging; however, there is still no clear information on the factors that are most affected by aging. The aim of this study was to compare two groups of runners (< 50 and > 50 years of age) according to their absolute, weight-adjusted maximal oxygen uptake (V̇O2max), lower limb lean mass-adjusted V̇O2max, ventilatory threshold, and respiratory compensation point (RCP). A total of 78 male recreational long-distance runners were divided into Group 1 (38.12 ± 6.87 years) and Group 2 (57.55 ± 6.14 years). Participants were evaluated for body composition, V̇O2max, VT, and RCP. Group 1 showed higher absolute and body mass-adjusted V̇O2max (4.60 ± 0.57 l·min-1 and 61.95 ± 8.25 ml·kg-1·min-1, respectively) than Group 2 (3.77 ± 0.56 l·min-1 and 51.50 ± 10.22 ml·kg-1·min-1, respectively), indicating a significant difference (p < 0.001, d =  - 1.46 and p < 0.001, d =  - 1.16). Correspondingly, Group 1 showed a significantly higher lower limb lean mass-adjusted V̇O2max (251.72 ± 29.60 ml·kgLM-1·min-1) than Group 2 (226.36 ± 43.94 ml·kgLM-1·min-1) (p = 0.008, d =  - 0.71). VT (%V̇O2max) (p = 0.19, d = 0.19) and RCP (%V̇O2max) (p = 0.24, d = 0.22) did not differ between the groups. These findings suggest that both variables that are limited by central or peripheral conditions are negatively affected by aging, but the magnitude of the effect is higher in variables limited by central conditions. These results contribute to our understanding of how aging affects master runners.

Observational and genetic associations between cardiorespiratory fitness and cancer: a UK Biobank and international consortia study

BACKGROUND

The association of fitness with cancer risk is not clear.

METHODS

We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of lung, colorectal, endometrial, breast, and prostate cancer in a subset of UK Biobank participants who completed a submaximal fitness test in 2009-12 (N = 72,572). We also investigated relationships using two-sample Mendelian randomisation (MR), odds ratios (ORs) were estimated using the inverse-variance weighted method.

RESULTS

After a median of 11 years of follow-up, 4290 cancers of interest were diagnosed. A 3.5 ml O2⋅min-1⋅kg-1 total-body mass increase in fitness (equivalent to 1 metabolic equivalent of task (MET), approximately 0.5 standard deviation (SD)) was associated with lower risks of endometrial (HR = 0.81, 95% CI: 0.73-0.89), colorectal (0.94, 0.90-0.99), and breast cancer (0.96, 0.92-0.99). In MR analyses, a 0.5 SD increase in genetically predicted O2⋅min-1⋅kg-1 fat-free mass was associated with a lower risk of breast cancer (OR = 0.92, 95% CI: 0.86-0.98). After adjusting for adiposity, both the observational and genetic associations were attenuated.

DISCUSSION

Higher fitness levels may reduce risks of endometrial, colorectal, and breast cancer, though relationships with adiposity are complex and may mediate these relationships. Increasing fitness, including via changes in body composition, may be an effective strategy for cancer prevention.

The relationship between skeletal muscle mass and exercise capacity in patients undergoing hemodialysis: An exploratory secondary-analysis

BACKGROUND

Protein-energy wasting is commonly observed in patients undergoing hemodialysis, leading to reduced muscle mass and, in severe cases, sarcopenia, which significantly impacts the patients' quality of life and clinical outcomes. Exercise interventions are frequently employed to address muscle loss in these patients. However, the relationship between exercise capacity and skeletal muscle mass in this context remains uncertain. In this study, researchers conducted a series of body composition analysis and exercise capacity test to explore the relationship between exercise capacity and skeletal muscle mass.

METHODS

This study recruited 32 patients undergoing hemodialysis and analyzed their demographic and clinical parameters. To assess aerobic exercise capacity, the incremental shuttle walking test (ISWT) was conducted, while the handgrip strength test was used to evaluate muscle strength. The patients' body compositions were assessed using the Fresenius Body Composition Monitor, and the appendicular skeletal muscle was scanned using a GE Healthcare Lunar iDXA scanner. Three sequential linear models were employed to model the relationship between ISWT and skeletal muscle mass. Model 1 regressed ISWT against gender and age; Model 2 added handgrip strength, fat tissue index, and Davies comorbidity scores as additional predictors; and Model 3 further included the appendicular skeletal muscle index (appendicular skeletal muscle/height).

FINDINGS

After controlling for age and gender (Model 1: R2  = 0.373), and subsequently including handgrip strength, fat tissue index, and Davies comorbidity score effects (Model 2: R2  = 0.581), the impact of appendicular skeletal muscle on ISWT was found to be non-significant (Model 3: R2  = 0.600).

CONCLUSION

There was no significant correlation observed between exercise capacity and skeletal muscle mass in patients undergoing hemodialysis, indicating the factors influencing exercise capacity in this patient population are complex and that increasing skeletal muscle mass may not necessarily involve solely addressing the improvement of exercise capacity.

EFFECTS OF HIGH-INTENSITY TRAINING ON ENDURANCE IN BASKETBALL PLAYERS

ABSTRACT Introduction: The aerobic endurance training of sports athletes has become the focus of research in institutions and related units. One of the recent proposals is high-intensity interval training to develop athletic aerobic endurance. Objective: Study the effect of high-intensity interval training on aerobic endurance in basketball players. Methods: Fifteen athletes from a university were randomly selected and divided into a high-intensity interval training group, a moderate-intensity continuous training group, and a low-intensity continuous training group, with the control of external influence factors. The indicators analyzed were the average aerobic endurance index of maximal oxygen consumption, average anaerobic capacity, and average maximal power output. The data were obtained before and after the experiment. They were compared and discussed using statistical analysis. Results: The average maximal oxygen consumption in the three training groups increased significantly, and the effect was most evident under the high-intensity intermittent training conditions. This training method could increase the maximal exercise time of the normal groups by up to two times. Conclusion: Intermittent high-intensity training can effectively improve the aerobic endurance of basketball players. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.