V˙o 2 kinetics in heavy exercise is not altered by prior exercise with a different muscle group

2002 ◽  
Vol 92 (6) ◽  
pp. 2467-2474 ◽  
Author(s):  
Yoshiyuki Fukuba ◽  
Naoyuki Hayashi ◽  
Shunsaku Koga ◽  
Takayoshi Yoshida
Keyword(s):  
Near Infrared ◽  
Slow Component ◽  
Exponential Model ◽  
Muscle Group ◽  
Heavy Exercise ◽  
Arm Cranking ◽  
Warm Up ◽  
Leg Muscles ◽  
Leg Cycling ◽  
Lactic Acidemia

We examined whether lactic acidemia-induced hyperemia at the onset of high-intensity leg exercise contributed to the speeding of pulmonary O2 uptake (V˙o 2) after prior heavy exercise of the same muscle group or a different muscle group (i.e., arm). Six healthy male subjects performed two protocols that consisted of two consecutive 6-min exercise bouts separated by a 6-min baseline at 0 W: 1) both bouts of heavy (work rate: 50% of lactate threshold to maximal V˙o 2) leg cycling (L1-ex to L2-ex) and 2) heavy arm cranking followed by identical heavy leg cycling bout (A1-ex to A2-ex). Blood lactate concentrations before L1-ex, L2-ex, and A2-ex averaged 1.7 ± 0.3, 5.6 ± 0.9, and 6.7 ± 1.4 meq/l, respectively. An “effective” time constant (τ) of V˙o 2 with the use of the monoexponential model in L2-ex (τ: 36.8 ± 4.3 s) was significantly faster than that in L1-ex (τ: 52.3 ± 8.2 s). Warm-up arm cranking did not facilitate theV˙o 2 kinetics for the following A2-ex [τ: 51.7 ± 9.7 s]. The double-exponential model revealed no significant change of primary τ (phase II)V˙o 2 kinetics. Instead, the speeding seen in the effective τ during L2-ex was mainly due to a reduction of theV˙o 2 slow component. Near-infrared spectroscopy indicated that the degree of hyperemia in working leg muscles was significantly higher at the onset of L2-ex than A2-ex. In conclusion, facilitation of V˙o 2 kinetics during heavy exercise preceded by an intense warm-up exercise was caused principally by a reduction in the slow component, and it appears unlikely that this could be ascribed exclusively to systemic lactic acidosis.

Oxygen uptake kinetics for moderate exercise are speeded in older humans by prior heavy exercise

2002 ◽  
Vol 92 (2) ◽  
pp. 609-616 ◽  
Author(s):  
Barry W. Scheuermann ◽  
Chris Bell ◽  
Donald H. Paterson ◽  
Thomas J. Barstow ◽  
John M. Kowalchuk
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Muscle Blood Flow ◽  
Exponential Model ◽  
Work Rate ◽  
Moderate Intensity ◽  
Moderate Exercise ◽  
Heavy Exercise ◽  
Younger Adults ◽  
Warm Up

This study examined the effect of heavy-intensity warm-up exercise on O2 uptake (V˙o 2) kinetics at the onset of moderate-intensity (80% ventilation threshold), constant-work rate exercise in eight older (65 ± 2 yr) and seven younger adults (26 ± 1 yr). Step increases in work rate from loadless cycling to moderate exercise (Mod1), heavy exercise, and moderate exercise (Mod2) were performed. Each exercise bout was 6 min in duration and separated by 6 min of loadless cycling.V˙o 2 kinetics were modeled from the onset of exercise by use of a two-component exponential model. Heart rate (HR) kinetics were modeled from the onset of exercise using a single exponential model. During Mod1, the time constant (τ) for the predominant rise in V˙o 2(τV˙o 2) was slower ( P < 0.05) in the older adults (50 ± 10 s) than in young adults (19 ± 5 s). The older adults demonstrated a speeding ( P < 0.05) of V˙o 2kinetics when moderate-intensity exercise (Mod2) was preceded by high-intensity warm-up exercise (τV˙o 2, 27 ± 3 s), whereas young adults showed no speeding of V˙o 2kinetics (τV˙o 2, 17 ± 3 s). In the older and younger adults, baseline HR preceding Mod2was elevated compared with Mod1, but the τ for HR kinetics was slowed ( P < 0.05) in Mod2only for the older adults. Prior heavy-intensity exercise in old, but not young, adults speeded V˙o 2 kinetics during Mod2. Despite slowed HR kinetics in Mod2in the older adults, an elevated baseline HR before the onset of Mod2 may have led to sufficient muscle perfusion and O2 delivery. These results suggest that, when muscle blood flow and O2 delivery are adequate, muscle O2consumption in both old and young adults is limited by intracellular processes within the exercising muscle.

V˙o 2 kinetics in the horse during moderate and heavy exercise

1997 ◽  
Vol 83 (4) ◽  
pp. 1235-1241 ◽  
Author(s):  
I. Langsetmo ◽  
G. E. Weigle ◽  
M. R. Fedde ◽  
H. H. Erickson ◽  
T. J. Barstow ◽  
...  
Keyword(s):  
Time Constant ◽  
Slow Component ◽  
Venous Blood ◽  
Exponential Model ◽  
Mixed Venous Blood ◽  
Phase 2 ◽  
Heavy Exercise ◽  
Two Phase ◽  
Treadmill Testing ◽  
Exercise Transitions

Langsetmo, I., G. E. Weigle, M. R. Fedde, H. H. Erickson, T. J. Barstow, and D. C. Poole.V˙o 2 kinetics in the horse during moderate and heavy exercise. J. Appl. Physiol. 83(4): 1235–1241, 1997.—The horse is a superb athlete, achieving a maximal O2 uptake (∼160 ml ⋅ min−1 ⋅ kg−1) approaching twice that of the fittest humans. Although equine O2 uptake (V˙o 2) kinetics are reportedly fast, they have not been precisely characterized, nor has their exercise intensity dependence been elucidated. To address these issues, adult male horses underwent incremental treadmill testing to determine their lactate threshold (Tlac) and peakV˙o 2(V˙o 2 peak), and kinetic features of theirV˙o 2 response to “square-wave” work forcings were resolved using exercise transitions from 3 m/s to a below-Tlac speed of 7 m/s or an above-Tlac speed of 12.3 ± 0.7 m/s (i.e., between Tlac andV˙o 2 peak) sustained for 6 min. V˙o 2 and CO2 output were measured using an open-flow system: pulmonary artery temperature was monitored, and mixed venous blood was sampled for plasma lactate.V˙o 2 kinetics at work levels below Tlac were well fit by a two-phase exponential model, with a phase 2 time constant (τ1 = 10.0 ± 0.9 s) that followed a time delay (TD1 = 18.9 ± 1.9 s). TD1 was similar to that found in humans performing leg cycling exercise, but the time constant was substantially faster. For speeds above Tlac, TD1 was unchanged (20.3 ± 1.2 s); however, the phase 2 time constant was significantly slower (τ1 = 20.7 ± 3.4 s, P < 0.05) than for exercise below Tlac. Furthermore, in four of five horses, a secondary, delayed increase inV˙o 2 became evident 135.7 ± 28.5 s after the exercise transition. This “slow component” accounted for ∼12% (5.8 ± 2.7 l/min) of the net increase in exercise V˙o 2. We conclude that, at exercise intensities below and above Tlac, qualitative features ofV˙o 2 kinetics in the horse are similar to those in humans. However, at speeds below Tlac the fast component of the response is more rapid than that reported for humans, likely reflecting different energetics of O2utilization within equine muscle fibers.

The influence of priming exercise on oxygen uptake, cardiac output, and muscle oxygenation kinetics during very heavy-intensity exercise in 9- to 13-yr-old boys

2010 ◽  
Vol 109 (2) ◽  
pp. 491-500 ◽  
Author(s):  
Alan R. Barker ◽  
Andrew M. Jones ◽  
Neil Armstrong
Keyword(s):  
Cardiac Output ◽  
Phase Ii ◽  
Near Infrared ◽  
Slow Component ◽  
Exercise Bout ◽  
Muscle Oxygenation ◽  
Heavy Exercise ◽  
Total Phase ◽  
Priming Exercise ◽  
Component Amplitude

The present study examined the effect of priming exercise on O2 uptake (V̇o2) kinetics during subsequent very heavy exercise in eight 9- to 13-yr-old boys. We hypothesised that priming exercise would 1) elevate muscle O2 delivery prior to the subsequent bout of very heavy exercise, 2) have no effect on the phase II V̇o2 τ, 3) elevate the phase II V̇o2 total amplitude, and 4) reduce the magnitude of the V̇o2 slow component. Each participant completed repeat 6-min bouts of very heavy-intensity cycling exercise separated by 6 min of light pedaling. During the tests V̇o2, muscle oxygenation (near infrared spectroscopy), and cardiac output (Q̇) (thoracic impedance) were determined. Priming exercise increased baseline muscle oxygenation and elevated Q̇ at baseline and throughout the second exercise bout. The phase II V̇o2 τ was not altered by priming exercise ( bout 1: 22 ± 7 s vs. bout 2: 20 ± 4 s; P = 0.30). However, the time constant describing the entire V̇o2 response from start to end of exercise was accelerated ( bout 1: 43 ± 8 s vs. bout 2: 36 ± 5 s; P = 0.002) due to an increased total phase II V̇o2 amplitude ( bout 1: 1.73 ± 0.33 l/min vs. bout 2: 1.80 ± 0.59 l/min; P = 0.002) and a reduced V̇o2 slow component amplitude ( bout 1: 0.18 ± 0.08 l/min vs. bout 2: 0.12 ± 0.09 l/min; P = 0.048). These results suggest that phase II V̇o2 kinetics in young boys is principally limited by intrinsic muscle metabolic factors, whereas the V̇o2 total phase II and slow component amplitudes may be O2 delivery sensitive.

Is the VO2 slow component in heavy arm-cranking exercise associated with recruitment of type II muscle fibers as assessed by an increase in surface EMG?

2006 ◽  
Vol 31 (4) ◽  
pp. 414-422 ◽  
Author(s):  
Sylvain Bernasconi ◽  
Nicolas Tordi ◽  
Stéphane Perrey ◽  
Bernard Parratte ◽  
Guy Monnier
Keyword(s):  
Ventilatory Threshold ◽  
Biceps Brachii ◽  
Slow Component ◽  
Muscle Fibers ◽  
Exponential Model ◽  
Type Ii ◽  
Triceps Brachii ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Arm Cranking

The recruitment of additional type II muscle fibers is one mechanism often suggested to be responsible for the slow component of oxygen uptake (VO2 SC). We hypothesized that surface electromyogram (EMG) of the biceps brachii, triceps brachii, anterior deltoid, and infraspinatus muscles could be related to the VO2 SC amplitude during arm-cranking exercises above ventilatory threshold (VT). Eight healthy subjects performed transitions from rest to 6-min heavy exercise at a constant power output of approximately 40% between VT and peak VO2. A 2-component exponential model was used to fit the VO2 response. EMG were recorded the last 15 s of each minute to obtain root mean square (RMS) and mean power frequency (MPF). Mean EMG responses for RMS and MPF were calculated by averaging EMG responses of the 4 muscles. The VO2 SC amplitude was of 530 ± 166 mL/min and occurred after 134 ± 31 s of exercise onset. Significant correlations were found for most of the subjects between EMG parameters and the VO2 SC amplitude as determined between the 2nd and the 6th minute. For all muscles, RMS values significantly increased over time during the VO2 SC, whereas MPF decreased significantly. These results suggest a relation between the recruitment of additional type II muscle fibers and the VO2 SC in arm-cranking exercises.

Cardiovascular responses to exercise as functions of absolute and relative work load

1983 ◽  
Vol 54 (5) ◽  
pp. 1314-1323 ◽  
Author(s):  
S. F. Lewis ◽  
W. F. Taylor ◽  
R. M. Graham ◽  
W. A. Pettinger ◽  
J. E. Schutte ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Muscle Mass ◽  
Cardiovascular Responses ◽  
Muscle Group ◽  
Exercise Heart Rate ◽  
Active Muscle ◽  
Vo2 Max ◽  
Arm Cranking ◽  
Wide Range ◽  
Leg Cycling

The roles of absolute and relative oxygen uptake (VO2 and percent of muscle group specific VO2 max) as determinants of the cardiovascular and ventilatory responses to exercise over a wide range of active muscle mass have not previously been defined. Six healthy men performed four types of dynamic exercise--one-arm curl, one-arm cranking, and one- and two-leg cycling at four different relative work loads--25, 50, 75, and 100% of VO2 max for the corresponding muscle group. VO2 during maximal one-arm curl, one-arm cranking, and one-leg cycling averaged 20, 50, and 75%, respectively, of that for maximal two-leg cycling. Cardiac output was linearly related to VO2 with a similar slope and intercept for each type of exercise. Heart rate at a given %VO2 max was higher with larger active muscle mass. In relation to %VO2 max, systemic resistance was lower and plasma catecholamine levels were higher with larger active muscle mass. The cardiovascular responses to exercise are determined to a large extent by the active muscle mass and the absolute oxygen uptake, with the principal feature appearing to be the tight linkage between systemic oxygen transport and utilization.

Dynamic Responses of Oxygen Uptake at the Onset and End of Moderate and Heavy Exercise in Trained Subjects

2004 ◽  
Vol 29 (1) ◽  
pp. 32-44 ◽  
Author(s):  
Christophe Cleuziou ◽  
Stéphane Perrey ◽  
Fabio Borrani ◽  
Anne Marie Lecoq ◽  
Robin Candau ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Ventilatory Threshold ◽  
Slow Component ◽  
Exponential Model ◽  
Dynamic Responses ◽  
Parameter Estimates ◽  
Heavy Exercise ◽  
Cycling Exercise ◽  
Trained Subjects ◽  
Key Words Oxygen Uptake

Inconsistencies about dynamic asymmetry between the on- and off-transient responses in [Formula: see text] are found in the literature. Therefore the purpose of this study was to examine [Formula: see text]on-and off-transients during moderate- and heavy-intensity cycling exercise in trained subjects. Ten men underwent an initial incremental test for the estimation of ventilatory threshold (VT) and, on different days, two bouts of square-wave exercise at moderate (< VT) and heavy (> VT) intensities. [Formula: see text] kinetics in exercise and recovery were better described by a single exponential model (< VT), or by a double exponential with two time delays (> VT). For moderate exercise, we found a symmetry of [Formula: see text] kinetics between the on- and off-transients (i.e., fundamental component), consistent with a system manifesting linear control dynamics. For heavy exercise, a slow component superimposed on the fundamental phase was expressed in both the exercise and recovery, with similar parameter estimates. But the on-transient values of the time constant were appreciably faster than the associated off-transient, and independent of the work rate imposed (< VT and > VT). Our results do not support a dynamically linear system model of [Formula: see text] during cycling exercise in the heavy-intensity domain. Key words: oxygen uptake kinetics, on- and off-transients, slow component

Prior exercise speeds pulmonary O2 uptake kinetics by increases in both local muscle O2 availability and O2 utilization

2007 ◽  
Vol 103 (3) ◽  
pp. 771-778 ◽  
Author(s):  
Darren S. DeLorey ◽  
John M. Kowalchuk ◽  
Aaron P. Heenan ◽  
Gregory R. duManoir ◽  
Donald H. Paterson
Keyword(s):  
Near Infrared ◽  
Slow Component ◽  
Vastus Lateralis ◽  
Knee Extension ◽  
Vastus Lateralis Muscle ◽  
Phase 2 ◽  
Warm Up ◽  
Prior Exercise ◽  
Exercise Onset ◽  
Monoexponential Model

The effect of prior exercise on pulmonary O2 uptake (V̇o2p), leg blood flow (LBF), and muscle deoxygenation at the onset of heavy-intensity alternate-leg knee-extension (KE) exercise was examined. Seven subjects [27 ( 5 ) yr; mean (SD)] performed step transitions ( n = 3; 8 min) from passive KE following no warm-up (HVY 1) and heavy-intensity (Δ50%, 8 min; HVY 2) KE exercise. V̇o2p was measured breath-by-breath; LBF was measured by Doppler ultrasound at the femoral artery; and oxy (O2Hb)-, deoxy (HHb)-, and total (Hbtot) hemoglobin/myoglobin of the vastus lateralis muscle were measured continuously by near-infrared spectroscopy (NIRS; Hamamatsu NIRO-300). Phase 2 V̇o2p, LBF, and HHb data were fit with a monoexponential model. The time delay (TD) from exercise onset to an increase in HHb was also determined and an HHb effective time constant (HHb − MRT = TD + τ) was calculated. Prior heavy-intensity exercise resulted in a speeding ( P < 0.05) of phase 2 V̇o2p kinetics [HVY 1: 42 s ( 6 ); HVY 2: 37 s ( 8 )], with no change in the phase 2 amplitude [HVY 1: 1.43 l/min (0.21); HVY 2: 1.48 l/min (0.21)] or amplitude of the V̇o2p slow component [HVY 1: 0.18 l/min (0.08); HVY 2: 0.18 l/min (0.09)]. O2Hb and Hbtot were elevated throughout the on-transient following prior heavy-intensity exercise. The τLBF [HVY 1: 39 s ( 7 ); HVY 2: 47 s ( 21 ); P = 0.48] and HHb-MRT [HVY 1: 23 s ( 4 ); HVY 2: 21 s ( 7 ); P = 0.63] were unaffected by prior exercise. However, the increase in HHb [HVY 1: 21 μM ( 10 ); HVY 2: 25 μM ( 10 ); P < 0.001] and the HHb-to-V̇o2p ratio [(HHb/V̇o2p) HVY 1: 14 μM·l−1·min−1 ( 6 ); HVY 2: 17 μM·l−1·min−1 ( 5 ); P < 0.05] were greater following prior heavy-intensity exercise. These results suggest that the speeding of phase 2 τV̇o2p was the result of both elevated local O2 availability and greater O2 extraction evidenced by the greater HHb amplitude and HHb/V̇o2p ratio following prior heavy-intensity exercise.

scholarly journals Effects of prior heavy exercise onV˙o 2 kinetics during heavy exercise are related to changes in muscle activity

2002 ◽  
Vol 93 (1) ◽  
pp. 167-174 ◽  
Author(s):  
Mark Burnley ◽  
Jonathan H. Doust ◽  
Derek Ball ◽  
Andrew M. Jones
Keyword(s):  
Slow Component ◽  
Vastus Lateralis ◽  
Gluteus Maximus ◽  
Exercise Bout ◽  
Motor Units ◽  
Primary Response ◽  
Heavy Exercise ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Leg Cycling

We hypothesized that the elevated primary O2 uptake (V˙o 2) amplitude during the second of two bouts of heavy cycle exercise would be accompanied by an increase in the integrated electromyogram (iEMG) measured from three leg muscles (gluteus maximus, vastus lateralis, and vastus medialis). Eight healthy men performed two 6-min bouts of heavy leg cycling (at 70% of the difference between the lactate threshold and peakV˙o 2) separated by 12 min of recovery. The iEMG was measured throughout each exercise bout. The amplitude of the primary V˙o 2 response was increased after prior heavy leg exercise (from mean ± SE 2.11 ± 0.12 to 2.44 ± 0.10 l/min, P < 0.05) with no change in the time constant of the primary response (from 21.7 ± 2.3 to 25.2 ± 3.3 s), and the amplitude of theV˙o 2 slow component was reduced (from 0.79 ± 0.08 to 0.40 ± 0.08 l/min, P < 0.05). The elevated primary V˙o 2 amplitude after leg cycling was accompanied by a 19% increase in the averaged iEMG of the three muscles in the first 2 min of exercise (491 ± 108 vs. 604 ± 151% increase above baseline values, P < 0.05), whereas mean power frequency was unchanged (80.1 ± 0.9 vs. 80.6 ± 1.0 Hz). The results of the present study indicate that the increased primaryV˙o 2 amplitude observed during the second of two bouts of heavy exercise is related to a greater recruitment of motor units at the onset of exercise.

IMPACT OF LOCAL VIBROSTIMULATION ON PARAMETERS OF LEG MUSCLES STRENGTH ENDURANCE

2019 ◽  
Vol 4 ◽  
pp. 84
Author(s):  
Uģis Ciematnieks ◽  
Justīne Poda
Keyword(s):  
Knee Extension ◽  
Muscle Group ◽  
Whole Body ◽  
Local Vibration ◽  
Warm Up ◽  
Leg Extension ◽  
Leg Strength ◽  
Leg Muscles ◽  
Long Time ◽  
Femoris Muscle

Vibration as a tool for massage and rehabilitation has been known for a long time. However, the vibration as a tool in sport workout is used very recently and is being used to increase strength, power, flexibility and coordination. It should also be noted that proper dosing of whole-body vibration plays a very important role in lymph drainage and in the treatment of overloaded joints. Improving and retaining physical fitness as well as repeating sets of exercises on one muscle group to spend as much energy resources in this muscle is important in fitness, in order to increase muscle mass and conditioning. Tonic effect of local vibrostimulation can warm up single muscle or muscle group, but also it can lead to excessive fatigue. So the aim of research is assessment of the effects of local vibrostimulation on the strength endurance for women in seated knee extension motion. Literature was analysed and an experiment was used to find out how strength endurance parameters change for 18-23 year old women after local vibration stimulation. A study was conducted with 20 women aged 18 to 23 years. For these women, control of single leg strength endurance was performed by seated leg extension movement, followed by local vibrostimulation of the quadriceps femoris muscle. This procedure was followed by a repeated strength endurance control. In this study, we found that the strength endurance parameters of the stimulated leg increased by an average of 5 repetitions during 30 seconds of control motion. We conclude that dosed local vibrostimulation sessions can increase strength endurance parameters locally for one muscle group.

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