Factors limiting maximal oxygen uptake in exertional monoparesis

2005 ◽  
Vol 11 (2) ◽  
pp. 240-241 ◽  
Author(s):  
Lesley J White ◽  
Rudolph H Dressendorfer
Keyword(s):  
Multiple Sclerosis ◽  
Oxygen Uptake ◽  
Delivery System ◽  
Maximal Oxygen Uptake ◽  
Work Capacity ◽  
Oxidative Capacity ◽  
Quadriceps Strength ◽  
Muscle Oxidative Capacity ◽  
The Right ◽  
Aerobic Work Capacity

Strength and maximal oxygen uptake (VO2max) for each leg were compared in a trained multiple sclerosis (MS) patient with exertional left monoparesis. Left quadriceps strength and left leg VO2max were 22% and 30% lower, respectively, compared to the right (control) leg. Because the same O2 delivery system served each leg during exercise, VO2max of the paretic leg was not limited by cardiorespiratory factors but rather by strength and/or muscle oxidative capacity. However, training with monoparesis likely enhanced O2 extraction and aerobic work capacity of the right leg.

Use of respiratory quotients in assessment of aerobic work capacity

1962 ◽  
Vol 17 (1) ◽  
pp. 47-50 ◽  
Author(s):  
B. Issekutz ◽  
N. C. Birkhead ◽  
K. Rodahl
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Work Load ◽  
Work Capacity ◽  
Bicycle Ergometer ◽  
Carbon Dioxide Output ◽  
Ergometer Test ◽  
Aerobic Work Capacity ◽  
Bicycle Ergometer Test ◽  
Better Than

Oxygen uptake and carbon dioxide output were measured in 32 untrained subjects during exercise on the bicycle ergometer. It was shown that the work respiratory quotient (RQ) under standardized conditions can be used as a measure of physical fitness. ΔRQ (work RQ minus 0.75) increases logarithmically with the work load and maximal O2 uptake is reached at a ΔRQ value of 0.40. This observation offered the possibility of predicting the maximal O2 uptake of a person, based on the measurement of RQ during a single bicycle ergometer test at a submaximal load. For each work RQ between 0.95 and 1.15 a factor was presented, together with the aid of a simple equation, which gave a good approximation (generally better than ±10%) of the maximal O2 uptake.

Aerobic work capacity in middle-aged Norwegian men

1965 ◽  
Vol 20 (3) ◽  
pp. 432-436 ◽  
Author(s):  
K. Lange Andersen ◽  
Lars Hermansen
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Age Groups ◽  
Older Men ◽  
Work Capacity ◽  
Maximal Heart Rate ◽  
Middle Aged ◽  
Younger Age ◽  
Exercise Induced ◽  
Aerobic Work Capacity

Maximal oxygen uptake and related respiratory and circulatory functions were measured in sedentary and well-trained middle-aged men. Maximal oxygen uptakes averaged 2.63 liter/min in sedentary men and 3.36 liter/min in well-trained men, the latter value being essentially the same as found in young untrained students. The heart rate/ oxygen uptake relationship was found to be the same for sedentary-living men, regardless of age, but maximal heart rate was lower in older men. The maximal heart rate is probably the same in well-trained as in sedentary middle-aged men, this in contrast to what has been observed in younger age groups, where training reduces maximal heart rate. The exercise-induced hyperventilation takes place at an oxygen uptake corresponding to 70–80% of the capacity, this being the same in trained and untrained, and essentially the same as found in young adult subjects. maximal O2 uptake Submitted on March 23, 1964

scholarly journals NIRS-derived skeletal muscle oxidative capacity is correlated with aerobic fitness and independent of sex

2020 ◽  
Vol 129 (3) ◽  
pp. 558-568
Author(s):  
Austin T. Beever ◽  
Thomas R. Tripp ◽  
Jenny Zhang ◽  
Martin J. MacInnis
Keyword(s):  
Skeletal Muscle ◽  
Infrared Spectroscopy ◽  
Oxygen Uptake ◽  
Aerobic Fitness ◽  
Lactate Threshold ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Oxidative Capacity ◽  
Muscle Oxidative Capacity ◽  
Respiratory Compensation

Near-infrared spectroscopy (NIRS) can be used to measure skeletal muscle oxidative capacity. Here, we demonstrated that NIRS-derived skeletal muscle oxidative capacity of the vastus lateralis was independent of sex, reliable across and within days, and correlated with maximal and submaximal indices of aerobic fitness, including maximal oxygen uptake, lactate threshold, and respiratory compensation point. These findings highlight the utility of NIRS for investigating skeletal muscle oxidative capacity in females and males.

scholarly journals Is Walking Capacity in Subjects with Multiple Sclerosis Primarily Related to Muscle Oxidative Capacity or Maximal Muscle Strength? A Pilot Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Dominique Hansen ◽  
Peter Feys ◽  
Inez Wens ◽  
Bert O. Eijnde
Keyword(s):  
Multiple Sclerosis ◽  
Muscle Strength ◽  
Multivariate Regression ◽  
Oxidative Capacity ◽  
Regression Analyses ◽  
Muscle Oxidative Capacity ◽  
Mean Response Time ◽  
Walking Capacity ◽  
The Impact ◽  
Maximal Muscle Strength

Background and Purpose. Walking capacity is reduced in subjects with multiple sclerosis (MS). To develop effective exercise interventions to enhance walking capacity, it is important to determine the impact of factors, modifiable by exercise intervention (maximal muscle strength versus muscle oxidative capacity), on walking capacity. The purpose of this pilot study is to discriminate between the impact of maximal muscle strength versus muscle oxidative capacity on walking capacity in subjects with MS.Methods. From 24 patients with MS, muscle oxidative capacity was determined by calculation of exercise-onset oxygen uptake kinetics (mean response time) during submaximal exercise bouts. Maximal muscle strength (isometric knee extension and flexion peak torque) was assessed on dynamometer. All subjects completed a 6-minute walking test. Relationships between walking capacity (as a percentage of normal value) and muscle strength (of knee flexors and extensors) versus muscle oxidative capacity were assessed in multivariate regression analyses.Results. The expanded disability status score (EDSS) showed a significant univariate correlation (r=-0.70,P<0.004) with walking capacity. In multivariate regression analyses, EDSS and mean response time, but not muscle strength, were independently related to walking capacity (P<0.05).Conclusions. Walking distance is, next to disability level and not taking neurologic symptoms/deficits into account, primarily related to muscle oxidative capacity in subjects with MS. Additional study is needed to further examine/verify these findings.

Contribution of central and peripheral adaptations to changes in maximal oxygen uptake following 4 weeks of sprint interval training

2018 ◽  
Vol 43 (10) ◽  
pp. 1059-1068 ◽  
Author(s):  
James P. Raleigh ◽  
Matthew D. Giles ◽  
Hashim Islam ◽  
Matthew Nelms ◽  
Robert F. Bentley ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Citrate Synthase ◽  
Interval Training ◽  
Maximal Activity ◽  
Capillary Density ◽  
Oxidative Capacity ◽  
Sprint Interval Training ◽  
Peripheral Arterial

The current study examined the contribution of central and peripheral adaptations to changes in maximal oxygen uptake (V̇O2max) following sprint interval training (SIT). Twenty-three males completed 4 weekly SIT sessions (8 × 20-s cycling bouts at ∼170% of work rate at V̇O2max, 10-s recovery) for 4 weeks. Following completion of training, the relationship between changes in V̇O2max and changes in central (cardiac output) and peripheral (arterial–mixed venous oxygen difference (a-vO2diff), muscle capillary density, oxidative capacity, fibre-type distribution) adaptations was determined in all participants using correlation analysis. Participants were then divided into tertiles on the basis of the magnitude of their individual V̇O2max responses, and differences in central and peripheral adaptations were examined in the top (HI; ∼10 mL·kg−1·min−1 increase in V̇O2max, p < 0.05) and bottom (LO; no change in V̇O2max, p > 0.05) tertiles (n = 8 each). Training had no impact on maximal cardiac output, and no differences were observed between the LO group and the HI group (p > 0.05). The a-vO2diff increased in the HI group only (p < 0.05) and correlated significantly (r = 0.71, p < 0.01) with changes in V̇O2max across all participants. Muscle capillary density (p < 0.02) and β-hydroxyacyl-CoA dehydrogenase maximal activity (p < 0.05) increased in both groups, with no between-group differences (p > 0.05). Citrate synthase maximal activity (p < 0.01) and type IIA fibre composition (p < 0.05) increased in the LO group only. Collectively, although the heterogeneity in the observed V̇O2max response following 4 weeks of SIT appears to be attributable to individual differences in systemic vascular and/or muscular adaptations, the markers examined in the current study were unable to explain the divergent V̇O2max responses in the LO and HI groups.

scholarly journals Muscle Dysfunction and Walking Impairment in Women with Multiple Sclerosis

2019 ◽  
Vol 21 (6) ◽  
pp. 249-256 ◽  
Author(s):  
T. Bradley Willingham ◽  
Deborah Backus ◽  
Kevin K. McCully
Keyword(s):  
Multiple Sclerosis ◽  
African American ◽  
Muscle Function ◽  
Oxidative Capacity ◽  
Muscle Endurance ◽  
Muscle Dysfunction ◽  
Walk Test ◽  
Muscle Oxidative Capacity ◽  
6Mwt Distance ◽  
Edss Score

Abstract Background: Recent evidence suggests that skeletal muscle dysfunction is involved in disability progression in people with multiple sclerosis (MS). However, the relationship between muscle dysfunction and walking impairments in MS remains unclear. Thus, the cross-sectional relationships between muscle-specific oxidative capacity and walking endurance in women with MS were evaluated. Methods: Twenty women with MS (11 African American, 9 white) were tested. Muscle oxidative capacity of the medial gastrocnemius was measured using near-infrared spectroscopy after electrical stimulation. Muscle endurance was evaluated using accelerometer-based mechanomyography during electrical stimulation. Muscle strength was measured during maximal voluntary plantarflexion using handheld dynamometry. Walking function was measured using the Timed 25-Foot Walk test and the 6-Minute Walk Test (6MWT). Results: Reduced muscle oxidative capacity (R2 = 0.68–0.71, P &lt; .01) and muscle endurance (R2 = 0.59–0.78, P &lt; .01) were associated with lower Timed 25-Foot Walk time and 6MWT distance. Muscle strength was weakly correlated to 6MWT distance (R2 = 0.21, P = .02). No differences in muscle function or clinical outcome measures were found between African American and white subgroups. Women with moderate-to-severe disability (Expanded Disability Status Scale [EDSS] score, 5.0–6.5) had significantly reduced muscle oxidative capacity, muscle endurance, and walking ability compared with women with mild disability (EDSS score, 2.5–4.5). Conclusions: Reductions in muscle function in people with MS are related to declines in walking function across all levels of disability. Muscle dysfunction is not differentially related to walking impairment in African American and white women with MS.

Renal clearances during prolonged supine exercise at different loads

1965 ◽  
Vol 20 (6) ◽  
pp. 1294-1298 ◽  
Author(s):  
Gunnar Grimby
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Work Capacity ◽  
Bicycle Ergometer ◽  
Work Intensity ◽  
Arterial Blood ◽  
Renal Clearances ◽  
Heavy Work ◽  
Aerobic Work Capacity ◽  
Male Subjects

Clearance of inulin (CIn) and para-aminohippuric acid (CPAH), cardiac output, oxygen uptake, and arterial blood pressure were measured in 15 healthy male subjects at rest and during supine exercise of 45 min duration on a bicycle ergometer. Work loads between 150 and 900 kpm/min were chosen. CPAH decreased with increasing work intensity (heart rate). At an oxygen uptake corresponding to half of the aerobic work capacity it was about 70% and at heavy work 35–45% of the value at rest. The renal fraction of the cardiac output averaged, at rest, 17% and decreased with increasing work loads to 2.5–5% as a minimum. CIn did not change significantly until heavy exercise was performed. The filtration fraction increased during exercise. clearances of inulin and para-aminohippuric acid; cardiac output Submitted on May 28, 1965

Whole-body cooling does not compromise muscle oxidative capacity in subjects with multiple sclerosis

2014 ◽  
Vol 35 (4) ◽  
pp. 805-811 ◽  
Author(s):  
Bert Op ’t Eijnde ◽  
Charly Keytsman ◽  
Inez Wens ◽  
Dominique Hansen
Keyword(s):  
Multiple Sclerosis ◽  
Oxidative Capacity ◽  
Whole Body ◽  
Muscle Oxidative Capacity ◽  
Body Cooling ◽  
Whole Body Cooling

Cardiac output during submaximal and maximal work

1964 ◽  
Vol 19 (2) ◽  
pp. 268-274 ◽  
Author(s):  
Per-Olof Åstrand ◽  
T. Edward Cuddy ◽  
Bengt Saltin ◽  
Jesper Stenberg
Keyword(s):  
Cardiac Output ◽  
Oxygen Uptake ◽  
Stroke Volume ◽  
Work Capacity ◽  
Bicycle Ergometer ◽  
Heart Volume ◽  
Arterial Blood ◽  
Maximal Cardiac Output ◽  
The Individual ◽  
Aerobic Work Capacity

In the present study oxygen uptake, cardiac output, stroke volume (dye-dilution technique) and oxygen content of arterial blood were determined in 11 women and 12 men, 20–31 years of age, at rest, and when performing submaximal and maximal work. At rest plasma volume (T-1824) and heart volume were determined. Sitting on the bicycle ergometer the stroke volume was 40–90% (mean 63%) of the maximum attained during exercise. Maximal stroke volume was essentially reached at a workload with an oxygen uptake of about 40% of the maximum and a heart rate about 110. No tendency to a decrease in stroke volume was noticed when maximal work was performed. The variation in stroke volume was ±4% during exercise in the range from 40 to 100% of the individual's aerobic work capacity. The maximal cardiac output was 18.5 liters/min for women and 24.1 liters for men. The correlation between heart volume on one side and maximal stroke volume and cardiac output on the other side was high and the expected one from the dimension of the individual. On submaximal as well as maximal exercise the women had a higher cardiac output per liter oxygen uptake than the men, and this can be explained by the lower concentration of hemoglobin in the women's blood. cardiac function during exercise; cardiac output stroke volume; cardiac output and arterial O2 content Submitted on October 3, 1963

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