Effects of acute hypoxia on cerebral and muscle oxygenation during incremental exercise

Subudhi, Andrew W.; Dimmen, Andrew C.; Roach, Robert C.

doi:10.1152/japplphysiol.01460.2006

Cited by 226 publications

(279 citation statements)

References 51 publications

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“…Reliability of tissue oxygenation indexes obtained by NIRS, evaluated by the intraclass correlation coefficient for repeated measurements on the same subject during different days, was found to be very high for skeletal muscle (41). NIRS measurements in muscle tissue have been shown to be well correlated with local venous O 2 saturation (48).…”

Section: Measurementsmentioning

confidence: 98%

Skeletal muscle oxidative function in vivo and ex vivo in athletes with marked hypertrophy from resistance training

Salvadego

Domenis

Lazzer

et al. 2013

Journal of Applied Physiology

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Oxidative function during exercise was evaluated in 11 young athletes with marked skeletal muscle hypertrophy induced by long-term resistance training (RTA; body mass 102.6 Ϯ 7.3 kg, mean Ϯ SD) and 11 controls (CTRL; body mass 77.8 Ϯ 6.0 kg). Pulmonary O2 uptake (V O2) and vastus lateralis muscle fractional O2 extraction (by near-infrared spectroscopy) were determined during an incremental cycle ergometer (CE) and one-leg knee-extension (KE) exercise. Mitochondrial respiration was evaluated ex vivo by high-resolution respirometry in permeabilized vastus lateralis fibers obtained by biopsy. Quadriceps femoris muscle cross-sectional area, volume (determined by magnetic resonance imaging), and strength were greater in RTA vs. CTRL (by ϳ40%, ϳ33%, and ϳ20%, respectively). V O2peak during CE was higher in RTA vs. CTRL (4.05 Ϯ 0.64 vs. 3.56 Ϯ 0.30 l/min); no difference between groups was observed during KE. The O2 cost of CE exercise was not different between groups. When divided per muscle mass (for CE) or quadriceps muscle mass (for KE), V O2 peak was lower (by 15-20%) in RTA vs. CTRL. Vastus lateralis fractional O2 extraction was lower in RTA vs. CTRL at all work rates, during both CE and KE. RTA had higher ADP-stimulated mitochondrial respiration (56.7 Ϯ 23.7 pmol O2·s Ϫ1 ·mg Ϫ1 ww) vs. CTRL (35.7 Ϯ 10.2 pmol O2·s Ϫ1 ·mg Ϫ1 ww) and a tighter coupling of oxidative phosphorylation. In RTA, the greater muscle mass and maximal force and the enhanced mitochondrial respiration seem to compensate for the hypertrophy-induced impaired peripheral O2 diffusion. The net results are an enhanced whole body oxidative function at peak exercise and unchanged efficiency and O 2 cost at submaximal exercise, despite a much greater body mass. skeletal muscle hypertrophy; mitochondrial respiration; oxidative metabolism during exercise RESISTANCE TRAINING PROGRAMS have been developed with the aim of improving variables of muscle function such as strength, power, speed, local muscular endurance, coordination, and flexibility (21). Resistance training is now considered an important part of training and rehabilitation programs for healthy subjects and for various types of patients, such as cardiac patients (45), patients with pulmonary diseases (10), patients undergoing prolonged bed-rest periods (2), or elderly subjects (28). In these populations, the combination of resistance training with the more conventional endurance exercise improves the patients' outcomes and quality of life (45).An increase in the cross-sectional area of skeletal muscle fibers and a shift of fiber-type distribution toward type 2 fibers are typical adaptations induced by resistance training; these adaptations enhance the muscle force-generating potential (12) but could represent an impairment to skeletal muscle oxidative metabolism. On the other hand, muscles with higher maximal force would need to recruit a lower number of motor units, and therefore more oxidative (and more efficient) muscle fibers (20,26). According to other authors, strength training may increas...

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Section: Measurementsmentioning

confidence: 98%

Skeletal muscle oxidative function in vivo and ex vivo in athletes with marked hypertrophy from resistance training

Salvadego

Domenis

Lazzer

et al. 2013

Journal of Applied Physiology

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show abstract

“…Reliability of muscle oxygenation indexes obtained by NIRS, evaluated by the intraclass correlation coefficient for repeated measurements on the same subject during different days, was recently found to be very high (43). NIRS measurements in muscle tissue (22) have been shown to be well correlated with local venous O2 saturation.…”

Section: Cycloergometric Exercise Protocolsmentioning

confidence: 99%

Lack of functional effects of neuromuscular electrical stimulation on skeletal muscle oxidative metabolism in healthy humans

Porcelli

Marzorati

Pugliese

et al. 2012

Journal of Applied Physiology

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-A recent study has demonstrated that neuromuscular electrical stimulation (NMES) determines, in vitro, a fast-to-slow shift in the metabolic profile of muscle fibers. The aim of the present study was to evaluate if, in the same subjects, these changes would translate, in vivo, into an enhanced skeletal muscle oxidative metabolism. Seven young men were tested (cycle ergometer) during incremental exercises up to voluntary exhaustion and moderate and heavy constant-load exercises (CLE). Measurements were carried out before and after an 8-wk training program by isometric bilateral NMES (quadriceps muscles), which induced an ϳ25% increase in maximal isometric force. Breathby-breath pulmonary O2 uptake (V O2) and vastus lateralis oxygenation indexes (by near-infrared spectroscopy) were determined. Skeletal muscle fractional O2 extraction was estimated by near-infrared spectroscopy on the basis of changes in concentration of deoxygenated hemoglobin ϩ myoglobin. Values obtained at exhaustion were considered "peak" values. The following functional evaluation variables were unaffected by NMES: peak V O2; gas exchange threshold; the V O2 vs. work rate relationship (O2 cost of cycling); changes in concentration of deoxygenated hemoglobin ϩ myoglobin vs. work rate relationship (related to the matching between O2 delivery and V O2); peak fractional O2 extraction; V O2 kinetics (during moderate and heavy CLE) and the amplitude of its slow component (during heavy CLE). Thus NMES did not affect several variables of functional evaluation of skeletal muscle oxidative metabolism. Muscle hypertrophy induced by NMES could impair peripheral O2 diffusion, possibly counterbalancing, in vivo, the fast-to-slow phenotypic changes that were observed in vitro, in a previous work, in the same subjects of the present study. strength training; muscle hypertrophy; near-infrared spectroscopy; gas exchange kinetics NEUROMUSCULAR ELECTRICAL STIMULATION (NMES) (26, 28) is widely utilized as a complement to voluntary exercise in athletes (27) and in patients, such as those with heart failure (46), chronic obstructive pulmonary disease (34), or cancer (6). NMES represents an obligatory choice for training in patients who cannot perform voluntary contractions, such as those with spinal cord lesions (10), or in patients immobilized for fractures or following ligament reconstruction surgery (42). It is well established that NMES leads to significant increases in muscle mass and maximal voluntary strength (13,26,39).The effects of NMES on oxidative metabolism appear rather controversial. At molecular level, Perez et al. (36) reported a higher succinic dehydrogenase activity after NMES training, whereas both citrate synthase and phosphofructokinase activities were unchanged. Kim et al. (21) reported, after a NMES training program, no changes in citrate synthase activity and number of capillaries. Nuhr et al. (35) showed an increase in the activity of citrate synthase associated with a decrease in the activity of glyceraldehyde phosphate dehydrogenase. Int...

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“…To date, several studies have used NIRS to examine alterations in cerebral oxygenation during dynamic exercise, and have found an increase in cerebral oxygenation with medium and high-intensity exercise Shibuya et al, 2004a;Subudhi et al, 2007;Suzuki et al, 2004). While a rather detailed understanding of brain activity during hand movement has been developed (Dettmers et al, 1995), less is known about the functional anatomy of motor control for leg or foot movements.…”

Section: Brain Activity and Motor Performancementioning

confidence: 99%

What Does Cerebral Oxygenation Tell Us About Central Motor Output?

Bourdillon¹,

Perrey²

2012

Neuroimaging - Cognitive and Clinical Neuroscience

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Effects of acute hypoxia on cerebral and muscle oxygenation during incremental exercise

Cited by 226 publications

References 51 publications

Skeletal muscle oxidative function in vivo and ex vivo in athletes with marked hypertrophy from resistance training

Skeletal muscle oxidative function in vivo and ex vivo in athletes with marked hypertrophy from resistance training

Lack of functional effects of neuromuscular electrical stimulation on skeletal muscle oxidative metabolism in healthy humans

What Does Cerebral Oxygenation Tell Us About Central Motor Output?

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