Muscle fiber recruitment and the slow component of O2 uptake: constant work rate vs. all-out sprint exercise.

  title={Muscle fiber recruitment and the slow component of O2 uptake: constant work rate vs. all-out sprint exercise.},
  author={Anni Vanhatalo and David C. Poole and Fred J. DiMenna and Stephen J Bailey and Andrew M. Jones},
  journal={American journal of physiology. Regulatory, integrative and comparative physiology},
  volume={300 3},
The slow component of pulmonary O(2) uptake (Vo(2)) during constant work rate (CWR) high-intensity exercise has been attributed to the progressive recruitment of (type II) muscle fibers. We tested the following hypotheses: 1) the Vo(2) slow component gain would be greater in a 3-min all-out cycle test than in a work-matched CWR test, and 2) the all-out test would be associated with a progressive decline, and the CWR test with a progressive increase, in muscle activation, as estimated from the… 

Figures and Tables from this paper

The slow component of pulmonary O2 uptake accompanies peripheral muscle fatigue during high-intensity exercise.

The temporal and quantitative association of decrements in muscle torque production and V̇o2 pSC suggest a common physiological mechanism between skeletal muscle fatigue and loss of muscle efficiency.

Respiratory muscle power and the slow component of O2 uptake.

The findings of this investigation support the thesis that the energetic contribution from respiratory muscles to the V˙O2sc amplitude is disproportionately higher during severe- compared with that during heavy-intensity exercise.

Pulmonary O2 uptake kinetics as a determinant of high-intensity exercise tolerance in humans.

Findings support the notions that 1) rapid Vo(2) adaptation at exercise onset allows a steady state to be achieved at higher work rates compared with when Vo (2) kinetics are slower; and 2) exercise exceeding this limit initiates a "fatigue cascade" linking W' to a progressive increase in the O( 2) cost of power production (Vo(2sc)), which, if continued, results in attainment of Vo( 2max) and exercise intolerance.

Influence of All-Out Start Duration on Pulmonary Oxygen Uptake Kinetics and High-Intensity Exercise Performance

The use of a brief (∼15 seconds) all-out start to improve performance in short-duration athletic events is supported and it is suggested that such a strategy may be ergogenic by increasing the rate of oxidative energy transfer during exercise while minimizing the extent of the concurrent muscle metabolic perturbation.

The Positive Effects of Priming Exercise on Oxygen Uptake Kinetics and High-Intensity Exercise Performance Are Not Magnified by a Fast-Start Pacing Strategy in Trained Cyclists

In trained endurance cyclists, an FS pacing strategy does not magnify the positive effects of priming exercise on the overall VO2 kinetics and short-term high-intensity performance.

Slow component of VO2 kinetics: mechanistic bases and practical applications.

It seems that muscle fatigue underpins the V·O₂ slow component, although the greater fatigue sensitivity of recruited type II fibers might still play a crucial role in the loss of muscle efficiency in both situations.

Examining work-to-rest ratios to optimize upper body sprint interval training

Traditional SIT appears to have enhanced VO2peak in the upper body over a short-term two-week intervention.

The Effect of Inspiratory Muscle Warm-Up on VO2 Kinetics during Submaximal Rowing

Investigation of the effect of an inspiratory muscle warm-up on the VO2 kinetics during submaximal intensity ergometer rowing found a positive association between VO2max from the incremental rowing test and τ1 from Test 1 (r = 0.71; p < 0.05), whereas VO2 did not correlate with τ2 from Test 2.

Oxygen uptake kinetics and speed-time correlates of modified 3-minute all-out shuttle running in soccer players

The linear running 3MT (r3MT) represents a viable surrogate to the GXT and data beyond CS and D’ may be gleaned by using the bi-exponential speed-time model.

A new incremental test for VO2max accurate measurement by increasing VO2max plateau duration, allowing the investigation of its limiting factors

It was shown that it was possible to get a long VO2max plateau at the end of NIT whatever the individualVO2max amplitude was, and the limiting factor of VO2 max duration was the power output.



Influence of muscle fiber type and pedal frequency on oxygen uptake kinetics of heavy exercise.

The hypothesis that the amplitude of the additional slow component of O2 uptake (VO2) during heavy exercise is correlated with the percentage of type II (fast-twitch) fibers in the contracting muscles is tested is tested and it is concluded that fiber type distribution significantly affects both the fast and slow components of VO2 duringheavy exercise.

Progressive recruitment of muscle fibers is not necessary for the slow component of VO2 kinetics.

A progressive recruitment of muscle fibers may not be necessary for the development of the slow component of VO2 kinetics, which may be caused by the metabolic factors that induce muscle fatigue and, as a consequence, reduce the efficiency of muscle contractions.

Is the VO2 slow component dependent on progressive recruitment of fast-twitch fibers in trained runners?

Results suggest a progression in the average frequency of the motor unit discharge toward the high frequencies, which coheres with the hypothesis of the progressive recruitment of fast-twitch fibers during the VO2 slow component.

Electromyographic data do not support a progressive recruitment of muscle fibers during exercise exhibiting a VO2 slow component.

The data indicated no relationship between MPF/EMG and the SC during heavy cycling, suggesting that the sensitivity of EMG may be insufficient to identify changes in muscle activity theorized to affect the VO2 SC.

Oxygen uptake kinetics during moderate, heavy and severe intensity ‘submaximal’ exercise in humans: the influence of muscle fibre type and capillarisation

It is demonstrated that muscle fibre type is significantly related to both the speed and the amplitudes of the .VO(2) response at the onset of constant-load sub-maximal exercise.

The slow component of O2 uptake is not accompanied by changes in muscle EMG during repeated bouts of heavy exercise in humans

These data are consistent with the view that the increased O2 cost associated with performing heavy exercise is coupled with a progressive increase in ATP requirements of the already recruited motor units rather than to changes in the recruitment pattern of slow versus fast‐twitch motor units.

Thigh muscle activation distribution and pulmonary VO2 kinetics during moderate, heavy, and very heavy intensity cycling exercise in humans.

Data are consistent with the notion that the Vo(2) slow component is an expression of progressive muscle recruitment during supra-LT exercise.

Muscle activation and the slow component rise in oxygen uptake during cycling.

The results support the hypothesis that during constant-rate exercise at intensities above lactate threshold, progressively greater use of fast-twitch motor units increases energy demand and causes concomitant progressive increases in VO2 and lactate.

Oxygen uptake kinetics during two bouts of heavy cycling separated by fatiguing sprint exercise in humans.

Vo (2) and Vco(2) kinetic responses to heavy exercise were markedly altered by prior multiple sprint exercises.

A prior bout of contractions speeds VO2 and blood flow on-kinetics and reduces the VO2 slow-component amplitude in canine skeletal muscle contracting in situ.

It is suggested that better matching of O2 delivery to VO2 speeds Vo(2) on-kinetics at this metabolic rate, but do not eliminate a potential role for enhanced metabolic activation.