Maximal oxygen consumption and energy cost of running after a long-lasting running race: the 100 km of Sahara

2008 ◽  
Vol 2 (3) ◽  
pp. 93-100 ◽  
Author(s):  
S. Fusi ◽  
D. Salvadego ◽  
V. Bresadola
Keyword(s):  
Oxygen Consumption ◽  
Energy Cost ◽  
Maximal Oxygen Consumption ◽  
Energy Cost Of Running

Energy Cost of Running in Well-Trained Athletes: Toward Slope-Dependent Factors

2021 ◽  
pp. 1-9
Author(s):  
Marcel Lemire ◽  
Romain Remetter ◽  
Thomas J. Hureau ◽  
Bernard Geny ◽  
Evelyne Lonsdorfer ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Lower Limb ◽  
Energy Cost ◽  
Cardiovascular Responses ◽  
Maximum Oxygen Consumption ◽  
Step Frequency ◽  
Physiological Factors ◽  
Vertical Stiffness ◽  
Energy Cost Of Running ◽  
Level Running

Purpose: This study aimed to determine the contribution of metabolic, cardiopulmonary, neuromuscular, and biomechanical factors to the energy cost (ECR) of graded running in well-trained runners. Methods: Eight men who were well-trained trail runners (age: 29 [10] y, mean [SD]; maximum oxygen consumption: 68.0 [6.4] mL·min−1·kg−1) completed maximal isometric evaluations of lower limb extensor muscles and 3 randomized trials on a treadmill to determine their metabolic and cardiovascular responses and running gait kinematics during downhill (DR: −15% slope), level (0%), and uphill running (UR: 15%) performed at similar O2 uptake (approximately 60% maximum oxygen consumption). Results: Despite similar O2 demand, ECR was lower in DR versus level running versus UR (2.5 [0.2] vs 3.6 [0.2] vs 7.9 [0.5] J·kg−1·m−1, respectively; all P < .001). Energy cost of running was correlated between DR and level running conditions only (r2 = .63; P = .018). Importantly, while ECR was correlated with heart rate, cardiac output, and arteriovenous O2 difference in UR (all r2 > .50; P < .05), ECR was correlated with lower limb vertical stiffness, ground contact time, stride length, and step frequency in DR (all r2 > .58; P < .05). Lower limb isometric extension torques were not related to ECR whatever the slope. Conclusion: The determining physiological factors of ECR might be slope specific, mainly metabolic and cardiovascular in UR versus mainly neuromuscular and mechanical in DR. This possible slope specificity of ECR during incline running opens the way for the implementation of differentiated physiological evaluations and training strategies to optimize performance in well-trained trail runners.

Rates of formation and oxidation of lactic acid in dogs at rest and during moderate exercise

1969 ◽  
Vol 47 (7) ◽  
pp. 603-610 ◽  
Author(s):  
Florent Depocas ◽  
Yves Minaire ◽  
Joseph Chatonnet
Keyword(s):  
Oxygen Consumption ◽  
Lactic Acid ◽  
Plasma Glucose ◽  
Energy Cost ◽  
Moderate Exercise ◽  
Plasma Lactate ◽  
Energy Cost Of Running ◽  
Extra Energy ◽  
Maximal Effort ◽  
Average Average

The rates of formation and oxidation of plasma lactic acid were measured in dogs, either resting quietly or running at 6 km/h on the level, by priming and continuous infusion with uniformly labelled 14C-lactic acid. During running at rates of oxygen consumption almost 5 times the resting value, corresponding to approximately 30% of the maximal effort, the rates of lactic acid formation and disposal were always greater than at rest and doubled on the average. Average plasma lactic acid concentrations during running were greater, equal, or lower than at rest in different dogs. The energy released by formation of the extra lactic acid from glucose during running represented, energetically, less than 0.5% of the extra energy cost of running. Seventy-four percent of the lactate formed was promptly converted to CO2, and about 12% of the respiratory carbon was derived from lactic acid in the running dogs. About 10% of the plasma glucose was derived from lactic acid during both rest and activity. At similar plasma lactate concentrations, running dogs had greater rates of formation of lactic acid than resting animals.

Energy cost of running, cycling and swimming in young triathletes of both sexes

1999 ◽  
Vol 24 (1) ◽  
pp. 301-305
Author(s):  
V. Bunc ◽  
J. Horcic ◽  
J. Heller ◽  
J. Formánek
Keyword(s):  
Energy Cost ◽  
Energy Cost Of Running

β-Adrenergic receptor number in human lymphocytes is inversely correlated with aerobic capacity

1998 ◽  
Vol 274 (6) ◽  
pp. E1106-E1112 ◽  
Author(s):  
Nobuharu Fujii ◽  
Sachiko Homma ◽  
Fumio Yamazaki ◽  
Ryoko Sone ◽  
Takeshi Shibata ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Aerobic Capacity ◽  
Adrenergic Receptor ◽  
Ventilatory Threshold ◽  
Human Lymphocytes ◽  
Mrna Level ◽  
Maximal Oxygen Consumption ◽  
Subsequent Degradation ◽  
Intracellular Compartments ◽  
Model Cell

In the present study, the relationships between β-adrenergic receptor (β-AR) expression and aerobic capacity evaluated by maximal oxygen consumption ([Formula: see text]) and oxygen consumption level at ventilatory threshold (V˙o 2@VT) were investigated. Seventeen physically untrained and 25 trained men participated in the study. After supine resting, the peripheral blood was sampled for preparation of lymphocytes, the model cell used to analyze the β-AR state. The total number of β-AR in lymphocytes (β-ARtotal) was inversely correlated with theV˙o 2 max( r = −0.368; P < 0.05) and theV˙o 2@VT ( r = −0.359; P < 0.05). Similar relationships were also observed between the number of β-AR in cell surface and both V˙o 2 max( r = −0.491; P < 0.05) andV˙o 2@VT ( r = −0.498; P < 0.05). However, no correlation was obtained between the number of β-AR in intracellular compartments and eitherV˙o 2 max orV˙o 2@VT. The β2-AR mRNA level quantified by the use of competitive reverse transcription-polymerase chain reaction was inversely correlated withV˙o 2@VT ( r = −0.567; P < 0.05) and positively correlated with β-ARtotal( r = 0.521; P < 0.05). These findings suggest that the β-AR number in lymphocytes is inversely correlated with aerobic capacity. This relationship may be explained by downregulation of β-AR, including internalization with subsequent degradation of the receptors and inhibition of the β-AR biosynthesis.

Responses to Intermittent Swimming Sets at Velocity Associated With max

2005 ◽  
Vol 30 (5) ◽  
pp. 543-553 ◽  
Author(s):  
Sebastien Libicz ◽  
Belle Roels ◽  
Gregoire P. Millet
Keyword(s):  
Oxygen Consumption ◽  
Maximal Oxygen Consumption ◽  
Interval Training ◽  
Swimming Velocity ◽  
Time Duration ◽  
Incremental Test ◽  
Large Variability ◽  
Equal Time ◽  
Physiological Adaptations ◽  
The Times

While the physiological adaptations following endurance training are relatively well understood, in swimming there is a dearth of knowledge regarding the metabolic responses to interval training (IT). The hypothesis tested predicted that two different endurance swimming IT sets would induce differences in the total time the subjects swam at a high percentage of maximal oxygen consumption [Formula: see text]. Ten trained triathletes underwent an incremental test to exhaustion in swimming so that the swimming velocity associated with [Formula: see text][Formula: see text] could be determined. This was followed by a maximal 400-m test and two intermittent sets at [Formula: see text] (a) 16 × 50 m with 15-s rest (IT50); (b) 8 × 100 m with 30-s rest (IT100). The times sustained above 95% [Formula: see text] (68.50 ± 62.69 vs. 145.01 ± 165.91 sec) and 95% HRmax (146.67 ± 131.99 vs. 169.78 ± 203.45 sec, p = 0.54) did not differ between IT50 and IT100 (values are mean ± SD). In conclusion, swimming IT sets of equal time duration at [Formula: see text] but of differing work-interval durations led to slightly different [Formula: see text] and HR responses. The time spent above 95% of [Formula: see text]max was twice as long in IT100 as in IT50, and a large variability between mean [Formula: see text] and HR values was also observed. Key words: interval training, maximal oxygen consumption, triathletes

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