Development Of Non-exercise Prediction Of Peak Oxygen Uptake By The Skeletal Muscle Mass And The Cardiac Dimensions

We compared the changes in maximum oxygen uptake (V·O2max) calculated per skeletal muscle mass (SMM) with conventional V·O2max measures in a 1-year training cycle. We hypothesized that the pattern of changes would differ between SMM-adjusted and absolute or weight-adjusted values, and the differences between groups of distinct training specialization and status will depend on the measure used. Twelve sprinters (24.7 ± 3.3 years), 10 endurance runners (25.3 ± 5.3 years), and 10 recreationally trained controls (29 ± 4.5 years) performed a treadmill test until exhaustion to determine V·O2max. Their SMM was estimated based on the dual X-ray absorptiometry method and a regression equation. The significance of differences was assessed using analysis of variance (p ≤ 0.05). The pattern of the longitudinal change was not different between V·O2max/SMM and standard measures. Also, the significance of differences between sprinters and endurance athletes remained similar regardless of the V·O2max measure. Sprinters and controls had similar absolute (~4.3 L·min−1) and total weight-adjusted (~52 vs. ~56 mL·min−1·kg) V·O2max, but they significantly differed in SMM-adjusted V·O2max (~110 vs. ~130 mL·min−1·kg SMM−1). In summary, SMM-adjusted V·O2max is not more useful than standard measures to track longitudinal changes in competitive athletes. However, it allows to better distinguish between groups or individuals differing in training status. The results of our study are limited to male athletes.

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Evaluation of oxygen uptake adjusted by skeletal muscle mass in cardiovascular disease patients with type 2 diabetes

Journal of Physical Therapy Science ◽

10.1589/jpts.33.94 ◽

2021 ◽

Vol 33 (2) ◽

pp. 94-99

Author(s):

Nana Takao ◽

Junji Iwasaka ◽

Satoshi Kurose ◽

Takumi Miyauchi ◽

Astuko Tamanoi ◽

...

Keyword(s):

Type 2 Diabetes ◽

Cardiovascular Disease ◽

Skeletal Muscle ◽

Oxygen Uptake ◽

Muscle Mass ◽

Skeletal Muscle Mass

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Underlying mechanisms of oxygen uptake kinetics in chronic post-stroke individuals: A correlational, cross-sectional pilot study

PLoS ONE ◽

10.1371/journal.pone.0241872 ◽

2020 ◽

Vol 15 (11) ◽

pp. e0241872

Author(s):

Jean Alex Matos Ribeiro ◽

Acson Gustavo da Silva Oliveira ◽

Luciana Di Thommazo-Luporini ◽

Clara Italiano Monteiro ◽

Gabriela Nagai Ocamoto ◽

...

Keyword(s):

Skeletal Muscle ◽

Oxygen Uptake ◽

Muscle Mass ◽

Skeletal Muscle Mass ◽

Augmentation Index ◽

Arterial Compliance ◽

Bootstrap Method ◽

Metabolic System ◽

Post Stroke ◽

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Post-stroke individuals presented deleterious changes in skeletal muscle and in the cardiovascular system, which are related to reduced oxygen uptake (V˙O2) and take longer to produce energy from oxygen-dependent sources at the onset of exercise (mean response time, MTRON) and during post-exercise recovery (MRTOFF). However, to the best of our knowledge, no previous study has investigated the potential mechanisms related to V˙O2 kinetics response (MRTON and MRTOFF) in post-stroke populations. The main objective of this study was to determine whether the MTRON and MRTOFF are related to: 1) body composition; 2) arterial compliance; 3) endothelial function; and 4) hematological and inflammatory profiles in chronic post-stroke individuals. Data on oxygen uptake (V˙O2) were collected using a portable metabolic system (Oxycon Mobile®) during the six-minute walk test (6MWT). The time to achieve 63% of V˙O2 during a steady state (MTRON) and recovery (MRTOFF) were analyzed by the monoexponential model and corrected by a work rate (wMRTON and wMRTOFF) during 6MWT. Correlation analyses were made using Spearman’s rank correlation coefficient (rs) and the bias-corrected and accelerated bootstrap method was used to estimate the 95% confidence intervals. Twenty-four post-stroke participants who were physically inactive took part in the study. The wMRTOFF was correlated with the following: skeletal muscle mass (rs = -0.46), skeletal muscle mass index (rs = -0.45), augmentation index (rs = 0.44), augmentation index normalized to a heart rate of 75 bpm (rs = 0.64), reflection magnitude (rs = 0.43), erythrocyte (rs = -0.61), hemoglobin (rs = -0.54), hematocrit (rs = -0.52) and high-sensitivity C-reactive protein (rs = 0.58), all p < 0.05. A greater amount of oxygen uptake during post-walking recovery is partially related to lower skeletal muscle mass, greater arterial stiffness, reduced number of erythrocytes and higher systemic inflammation in post-stroke individuals.

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