Muscle Oxygen Delivery in the Forearm and in the Vastus Lateralis Muscles in Response to Resistance Exercise: A Comparison Between Nepalese Porters and Italian Trekkers

This study compared the effects of the most frequently employed protocols of flywheel (FW) versus weight-stack (WS) resistance exercise (RE) on regional and muscle-specific adaptations of the knee extensors. Sixteen men (n = 8) and women (n = 8) performed 8 weeks (2–3 days/week) of knee extension RE employing FW technology on 1 leg (4 × 7 repetitions), while the contralateral leg performed regular WS training (4 × 8–12 repetitions). Maximal strength (1-repetition maximum (1RM) in WS) and peak FW power were determined before and after training for both legs. Partial muscle volume of vastus lateralis (VL), vastus medialis (VM), vastus intermedius (VI), and rectus femoris (RF) were measured using magnetic resonance imaging. Additionally, quadriceps cross-sectional area was assessed at a proximal and a distal site. There were no differences (P > 0.05) between FW versus WS in muscle hypertrophy of the quadriceps femoris (8% vs. 9%), VL (10% vs. 11%), VM (6% vs. 8%), VI (5% vs. 5%), or RF (17% vs. 17%). Muscle hypertrophy tended (P = 0.09) to be greater at the distal compared with the proximal site, but there was no interaction with exercise method. Increases in 1RM and FW peak power were similar across legs, yet the increase in 1RM was greater in men (31%) than in women (20%). These findings suggest that FW and WS training induces comparable muscle-specific hypertrophy of the knee extensors. Given that these robust muscular adaptations were brought about with markedly fewer repetitions in the FW compared with WS, it seems FW training can be recommended as a particularly time-efficient exercise paradigm.

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Abstract 2769: Impaired Skeletal Muscle Oxygen Utilization Contributes to Exercise Intolerance in Barth Syndrome

Circulation ◽

10.1161/circ.116.suppl_16.ii_615 ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Carolyn T Spencer ◽

Randall M Bryant ◽

Barry Byrne ◽

Elisabeth Heal ◽

Renee Margossian ◽

...

Keyword(s):

Skeletal Muscle ◽

Cardiac Function ◽

Mitochondrial Dysfunction ◽

Near Infrared ◽

Vastus Lateralis ◽

Barth Syndrome ◽

Exercise Intolerance ◽

Peak Exercise ◽

Indirect Measure ◽

Muscle Oxygen

Objective s: Barth Syndrome (BTHS) is an X-linked mutation in the TAZ gene characterized by cardiolipin deficiency, mitochondrial dysfunction and cardio-skeletal myopathy. We hypothe- sized that abnormal skeletal muscle oxygen (O 2 ) utilization contributes to exercise intolerance in BTHS. Methods : Boys with BTHS (n=13) and healthy male controls (n=7) performed a graded exercise test on a cycle ergometer with continuous metabolic and EKG monitoring. Near infrared spectroscopy (NIRS), an indirect measure of tissue O 2 saturation and index of skeletal muscle O 2 utilization, was applied to the vastus lateralis during exercise. Cardiac function in BTHS was assessed by echocardiography and serum BNP to examine the relationship between resting cardiac function and exercise capacity in BTHS. Results : Age (16±5 vs 13±3 years; p=0.22), BMI (17±3 vs. 20±5; p=0.14) and BSA (1.0±0.5 vs 1.2±0.6 m 2 ; p=0.3) were not different between BTHS and controls. BTHS had lower peak VO 2 (19±6 vs. 52±6 ml/kg/min, p < 0.001), lower % of predicted peak VO 2 (40±10% vs. 115±12%, p=0.0004), lower peak work rate (58±18 vs. 205±69 watts, p=0.0004), and lower peak O 2 pulse (4.6±1.6 vs. 14±6 ml O 2 /kg/beat, p< 0.00001) than controls. Peak HR in BTHS was lower but remained within normal peak predicted rate (172±14 vs. 197±11 bpm, p=0.001). Vastus lateralis tissue O 2 saturation at peak exercise decreased from baseline in controls as expected (-18±16%, p<0.001) but paradoxically increased from baseline in BTHS (+17±14%, p<0.03, p=0.0005 BTHS vs. controls) indicating impaired muscle O 2 utilization. Absolute (r= - 0.70, p<0.0001) and percent (r= - 0.70, p<0.001) change in NIRS from baseline was negatively associated with peak VO 2 . There was no correlation between peak VO 2 and resting EF (55±7%; r=0.12), SF (30±4%; r= -.26), myocardial performance index (0.4±0.1; r= -.3) or serum BNP (232±381; r=0.1). Conclusion : O 2 consumption during exercise in BTHS is severely reduced and caused, at least in part, by impaired skeletal muscle O 2 utilization. Resting cardiac function is not related to O 2 consumption in BTHS but cardiac dysfunction during exercise in BTHS is not excluded without further studies. Mitochondrial dysfunction likely mediates skeletal muscle O 2 utilization deficits during exercise in BTHS.

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The influence of muscle length on gastrocnemius and vastus lateralis muscle oxygen saturation and endurance

Journal of Electromyography and Kinesiology ◽

10.1016/j.jelekin.2019.102358 ◽

2019 ◽

Vol 49 ◽

pp. 102358 ◽

Cited By ~ 1

Author(s):

Sarah Williamson ◽

Adeola A. Sanni ◽

Kevin K. McCully

Keyword(s):

Oxygen Saturation ◽

Vastus Lateralis ◽

Muscle Length ◽

Vastus Lateralis Muscle ◽

Muscle Oxygen ◽

Lateralis Muscle

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Differences in muscle oxygenation between young and middle-aged recreationally active men during high-volume resistance exercise

Kinesiology ◽

10.26582/k.51.1.4 ◽

2019 ◽

Vol 51 (1) ◽

pp. 3-11

Author(s):

Yftach Gepner ◽

Joseph A. Gordon ◽

Jay R. Hoffman ◽

Jeffrey R. Stout ◽

David H. Fukuda ◽

...

Keyword(s):

Resistance Exercise ◽

Body Mass ◽

Vastus Lateralis ◽

Body Height ◽

High Volume ◽

Muscle Oxygenation ◽

Exercise Session ◽

Vastus Lateralis Muscle ◽

Middle Aged ◽

Volume Resistance

The aim of this study was to compare muscle oxygenation of the vastus lateralis during a high-volume isokinetic resistance exercise protocol (HVP) between young adult (YA) and middle-aged adult (MA) men. Twenty recreationally trained men were assigned to either the YA (age 21.8±2.0 years, body mass 90.7±11.6 kg, body height 179±4.7 cm) or MA (age 47.0±4.4 years, body mass 96.1±21.6 kg, body height 177±7.7 cm) group. The HVP consisted of eight sets of 10 repetitions of unilateral isokinetic concentric knee extension and eccentric knee flexion at 60°·s-1. Changes in tissue hemoglobin saturation index (TSI), tissue oxygenated hemoglobin concentration (O2Hb), deoxygenated hemoglobin (HHb), and muscle oxidation index (O2Hb-HHb) were measured during the exercise session using the near-infrared spectroscopy (NIRS). Data were analyzed using two-way mix factorial analyses of variance. Prior to exercise, TSI was significantly greater (p=.024) for YA compared to MA. Significant decreases in O2Hb and O2Hb-HHb and increases in HHb were observed during each of the eight sets relative to the rest periods (p<.05) for both groups. The average change during the eight sets of the HVP revealed a significantly higher (p=.036) level of HHb and a lower (p=.029) level of O2Hb-HHb for MA compared to YA. A significant negative correlation was also noted at baseline between O2Hb-HHb index and the cross-sectional area of the vastus lateralis muscle (r=-.45, p=.045). During a high- volume resistance exercise, MA experienced reduced muscle oxygen saturation levels compared to YA. These results may be attributed to reductions in local tissue oxidative capacity and reduced blood delivery occurring during middle-age, and possibly due to group differences in muscle morphology.

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Heliox increases quadriceps muscle oxygen delivery during exercise in COPD patients with and without dynamic hyperinflation

Journal of Applied Physiology ◽

10.1152/japplphysiol.00481.2012 ◽

2012 ◽

Vol 113 (7) ◽

pp. 1012-1023 ◽

Cited By ~ 18

Author(s):

Zafeiris Louvaris ◽

Spyros Zakynthinos ◽

Andrea Aliverti ◽

Helmut Habazettl ◽

Maroula Vasilopoulou ◽

...

Keyword(s):

Blood Flow ◽

Oxygen Content ◽

Oxygen Delivery ◽

Quadriceps Muscle ◽

Arterial Oxygen ◽

Arterial Oxygen Content ◽

Muscle Oxygen ◽

Peripheral Muscle ◽

Copd Patients ◽

Gastric Pressure

Some reports suggest that heliox breathing during exercise may improve peripheral muscle oxygen availability in patients with chronic obstructive pulmonary disease (COPD). Besides COPD patients who dynamically hyperinflate during exercise (hyperinflators), there are patients who do not hyperinflate (non-hyperinflators). As heliox breathing may differently affect cardiac output in hyperinflators (by increasing preload and decreasing afterload of both ventricles) and non-hyperinflators (by increasing venous return) during exercise, it was reasoned that heliox administration would improve peripheral muscle oxygen delivery possibly by different mechanisms in those two COPD categories. Chest wall volume and respiratory muscle activity were determined during constant-load exercise at 75% peak capacity to exhaustion, while breathing room air or normoxic heliox in 17 COPD patients: 9 hyperinflators (forced expiratory volume in 1 s = 39 ± 5% predicted), and 8 non-hyperinflators (forced expiratory volume in 1 s = 48 ± 5% predicted). Quadriceps muscle blood flow was measured by near-infrared spectroscopy using indocyanine green dye. Hyperinflators and non-hyperinflators demonstrated comparable improvements in endurance time during heliox (231 ± 23 and 257 ± 28 s, respectively). At exhaustion in room air, expiratory muscle activity (expressed by peak-expiratory gastric pressure) was lower in hyperinflators than in non-hyperinflators. In hyperinflators, heliox reduced end-expiratory chest wall volume and diaphragmatic activity, and increased arterial oxygen content (by 17.8 ± 2.5 ml/l), whereas, in non-hyperinflators, heliox reduced peak-expiratory gastric pressure and increased systemic vascular conductance (by 11.0 ± 2.8 ml·min−1·mmHg−1). Quadriceps muscle blood flow and oxygen delivery significantly improved during heliox compared with room air by a comparable magnitude (in hyperinflators by 6.1 ± 1.3 ml·min−1·100 g−1 and 1.3 ± 0.3 ml O2·min−1·100 g−1, and in non-hyperinflators by 7.2 ± 1.6 ml·min−1·100 g−1 and 1.6 ± 0.3 ml O2·min−1·100 g−1, respectively). Despite similar increase in locomotor muscle oxygen delivery with heliox in both groups, the mechanisms of such improvements were different: 1) in hyperinflators, heliox increased arterial oxygen content and quadriceps blood flow at similar cardiac output, whereas 2) in non-hyperinflators, heliox improved central hemodynamics and increased systemic vascular conductance and quadriceps blood flow at similar arterial oxygen content.

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Muscle-Specific Endurance of the Lower Back Erectors Using Electrical Twitch Mechanomyography

Journal of Functional Morphology and Kinesiology ◽

10.3390/jfmk4010012 ◽

2019 ◽

Vol 4 (1) ◽

pp. 12 ◽

Cited By ~ 2

Author(s):

Kevin McCully ◽

Caio Moraes ◽

Sahil Patel ◽

Max Green ◽

T. Willingham

Keyword(s):

Near Infrared ◽

Vastus Lateralis ◽

Erector Spinae ◽

Common Symptom ◽

Oxygen Levels ◽

Muscle Oxygen ◽

Skeletal Muscle Dysfunction ◽

Lower Back ◽

Coefficients Of Variation ◽

Healthy Participants

Lower back pain is a common symptom potentially associated with skeletal muscle dysfunction. The purpose of this study was to evaluate endurance in the lower back muscles of healthy participants using accelerometer-based mechanomyography. Methods: Young healthy subjects (N = 7) were tested. Surface electrodes and a tri-axial accelerometer were placed over the erector spinae muscle along the T11–L1 Vertebrae. Stimulation was for 3 min each at 2, 4, and 6 Hz, and changes in acceleration were used to calculate an endurance index (EI). Reproducibility of the endurance index measurements was tested on two separate days. Wrist flexor and vastus lateralis muscles were tested for comparison. Near Infrared Spectroscopy (NIRS) was used to measure muscle oxygen levels (O2Hb) (N = 5). EI was 70.3 + 13.4, 32.6 + 8.4, and 19.2 + 6.2% for 2, 4, 6 Hz, respectively. The coefficients of variation were 9.8, 13.9, and 20.3% for 2, 4, 6 Hz, respectively. EI values were lower in the erector spinae muscles compared to the arm and the leg (p < 0.05). O2Hb values were 86.4 + 10.9% at rest and were 77.2 + 15.5, 84.3 + 14.1, and 84.1 + 18.9% for 2, 4, 6 Hz, respectively (p > 0.05, all comparisons). An endurance index can be obtained from the lower back erectors muscles that is reproducible and not influenced by voluntary effort or muscle oxygen levels.

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Stimulation of myofibrillar synthesis by exercise is mediated by more efficient translation of mRNA

Journal of Applied Physiology ◽

10.1152/jappl.1999.86.4.1220 ◽

1999 ◽

Vol 86 (4) ◽

pp. 1220-1225 ◽

Cited By ~ 70

Author(s):

Stephen Welle ◽

Kirti Bhatt ◽

Charles A. Thornton

Keyword(s):

Protein Synthesis ◽

Resistance Exercise ◽

Vastus Lateralis ◽

Mrna Translation ◽

Human Muscle ◽

Total Rna ◽

Resistance Exercises ◽

Actin Mrna ◽

Membrane Hybridization ◽

Stimulation Of

Resistance exercises stimulate protein synthesis in human muscle, but the roles of changes in mRNA concentrations and changes in the efficiency of mRNA translation have not been defined. The present study was done to determine whether resistance exercise affects concentrations of total RNA, total mRNA, actin mRNA, or myosin heavy-chain mRNA (total and isoform specific). Eight subjects, 62–75 yr old, performed unilateral knee extensions at 80% of their one-repetition-maximum capacity on days 1, 3, and 6 of the study. On day 7, biopsies of exercised and nonexercised vastus lateralis muscles were obtained. Myofibrillar synthesis was determined by stable- isotope incorporation, and mRNA concentrations were determined by membrane hybridization and PCR-based methods. The exercise stimulated myofibrillar synthesis [30 ± 6 (SE)%] without affecting RNA or mRNA concentrations. The effect of exercise on protein synthesis in individual subjects did not correlate with the effect on total RNA and mRNA concentrations. These data suggest that the stimulation of myofibrillar synthesis by resistance exercise is mediated by more efficient translation of mRNA.

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