Hypoxia and Resistance Exercise: A Comparison of Localized and Systemic Methods

Scott, Brendan R.; Slattery, Katie M.; Sculley, Dean V.; Dascombe, Ben J.

doi:10.1007/s40279-014-0177-7

Cited by 124 publications

(156 citation statements)

References 138 publications

Supporting

Mentioning

150

Contrasting

Unclassified

Order By: Relevance

“…The molecular mechanisms responsible in this context have not yet been established but may be related to the hypoxia stimulus being intermittent and localized (Scott et al, 2014).…”

Section: Hypoxiamentioning

confidence: 99%

Molecular networks in skeletal muscle plasticity

Hoppeler

2016

Journal of Experimental Biology

168

117

View full text Add to dashboard Cite

The skeletal muscle phenotype is subject to considerable malleability depending on use as well as internal and external cues. In humans, low-load endurance-type exercise leads to qualitative changes of muscle tissue characterized by an increase in structures supporting oxygen delivery and consumption, such as capillaries and mitochondria. High-load strength-type exercise leads to growth of muscle fibers dominated by an increase in contractile proteins. In endurance exercise, stress-induced signaling leads to transcriptional upregulation of genes, with Ca 2+ signaling and the energy status of the muscle cells sensed through AMPK being major input determinants. Several interrelated signaling pathways converge on the transcriptional co-activator PGC-1α, perceived to be the coordinator of much of the transcriptional and post-transcriptional processes. Strength training is dominated by a translational upregulation controlled by mTORC1. mTORC1 is mainly regulated by an insulin-and/or growth-factor-dependent signaling cascade as well as mechanical and nutritional cues. Muscle growth is further supported by DNA recruitment through activation and incorporation of satellite cells. In addition, there are several negative regulators of muscle mass. We currently have a good descriptive understanding of the molecular mechanisms controlling the muscle phenotype. The topology of signaling networks seems highly conserved among species, with the signaling outcome being dependent on the particular way individual species make use of the options offered by the multi-nodal networks. As a consequence, muscle structural and functional modifications can be achieved by an almost unlimited combination of inputs and downstream signaling events.

show abstract

“…The molecular mechanisms responsible in this context have not yet been established but may be related to the hypoxia stimulus being intermittent and localized (Scott et al, 2014).…”

Section: Hypoxiamentioning

confidence: 99%

Molecular networks in skeletal muscle plasticity

Hoppeler

2016

Journal of Experimental Biology

168

117

View full text Add to dashboard Cite

show abstract

“…Recently, it has been proposed that increased levels of metabolic stress can impact on several downstream mechanisms to facilitate muscular hypertrophy [3,15]. For example, it is possible that metabolic stress can increase the recruitment of muscle fibres.…”

Section: Anabolic Effects Of Metabolic Stressmentioning

confidence: 99%

“…Furthermore, as the mechanisms underpinning adaptive responses to IHRT are not yet fully understood, it is possible that factors not related to metabolic stress (e.g. increased production of reactive oxygen species) may play a role in muscular development following this form of training [3]. Although it is likely that metabolic stress plays an important role in hypertrophic responses, it would be remiss not to recognize that skeletal muscle adaptations are vastly complex, and most probably affected by numerous physiological processes.…”

Section: Considerations For Training Programsmentioning

confidence: 99%

“…This technique creates a localized hypoxic environment in the limb during exercise, which is proposed to impact on downstream mechanisms that promote muscular development [3]. The novel aspect of training with BFR is that substantial improvements in muscular hypertrophy and strength are possible even when using low-loads (20-40% of concentric 1-repetition maximum [1RM]) for both clinical [4] and athletic [5,6] populations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Intermittent hypoxic resistance training: Is metabolic stress the key moderator?

Scott¹,

Slattery

Dascombe³

2015

Medical Hypotheses

Self Cite

View full text Add to dashboard Cite

Traditionally, researchers and practitioners have manipulated acute resistance exercise variables to elicit the desired responses to training. However, recent research indicates that altering the muscular environment during resistance training, namely by implementing a hypoxic stimulus, can augment muscle hypertrophy and strength.Intermittent hypoxic resistance training (IHRT), whereby participants inspire hypoxic air during resistance training, has been previously demonstrated to increase muscle cross-sectional area and maximum strength by significantly greater amounts than the equivalent training in normoxia. However, some recent evidence has provided conflicting results, reporting that the use of systemic hypoxia during resistance training provided no added benefit. While the definitive mechanisms that may augment muscular responses to IHRT are not yet fully understood, an increased metabolic stress is thought to be important for moderating many downstream processes related to hypertrophy. It is likely that methodological differences between conflicting IHRT studies have resulted in different degrees of metabolic stress during training, particularly when considering the inter-set recovery intervals used. Given that the most fundamental physiological stresses resulting from hypoxia are disturbances to oxidative metabolism, it becomes apparent that resistance training may only benefit from additional hypoxia if the exercise is structured to elicit a strong metabolic response. We hypothesize that for IHRT to be more effective in producing muscular hypertrophy and increasing strength than the equivalent normoxic training, exercise should be performed with relatively brief inter-set recovery periods, with the aim of providing a potent metabolic stimulus to enhance anabolic responses.3

show abstract

“…These responses are likely related to an increase in localized hypoxia during BFR, which effects beneficial acute changes in the intramuscular environment (28,31). For example, limited oxygen availability increases the reliance on anaerobic metabolism during exercise, augmenting intramuscular metabolic stress (30).…”

Section: Introductionmentioning

confidence: 99%

Physical Performance During High-Intensity Resistance Exercise in Normoxic and Hypoxic Conditions

Scott¹,

Slattery

Sculley

et al. 2015

Journal of Strength and Conditioning Research

Self Cite

View full text Add to dashboard Cite

This study aimed to determine whether different levels of hypoxia affect physical performance during high-intensity resistance exercise, or subsequent cardiovascular and perceptual responses. Twelve resistance-trained young men (age: 25.3 ± 4.3 yr; height: 179.0 ± 4.5 cm; body mass: 83.4 ± 9.1 kg) were tested for 1-repetition maximum (1RM) in the back squat and deadlift. Following this, participants completed three separate randomized trials of 5 x 5 repetitions at 80% 1RM, with 3 minutes rest between sets, in either normoxia, (NORM; fraction of inspired oxygen [F I O 2 ] = 0.21), moderate-level hypoxia (MH; F I O 2 = 0.16), or high-level hypoxia (HH; F I O 2 = 0.13) via a portable hypoxic unit. Peak and mean force and power variables were monitored during exercise. Arterial oxygen saturation (SpO 2 ), heart rate (HR), and rating of perceived exertion (RPE) were assessed immediately following each set.No differences in force or power variables were evident between conditions. Similar trends were evident in these variables across each set and across the exercise session in each condition. SpO 2 was lower in hypoxic conditions than in NORM, whereas HR was higher following sets performed in hypoxia. There were no differences between conditions in RPE.These results indicate that a hypoxic stimulus during high-intensity resistance exercise does not alter physical performance during repetitions and sets, or affect how strenuous exercise is perceived to be. This novel training strategy can be used without adversely affecting the physical training dose experienced, and may provide benefits over the equivalent training in normoxia.

show abstract

Hypoxia and Resistance Exercise: A Comparison of Localized and Systemic Methods

Cited by 124 publications

References 138 publications

Molecular networks in skeletal muscle plasticity

Molecular networks in skeletal muscle plasticity

Intermittent hypoxic resistance training: Is metabolic stress the key moderator?

Physical Performance During High-Intensity Resistance Exercise in Normoxic and Hypoxic Conditions

Contact Info

Product

Resources

About