Improvement of $$\dot{V}\hbox{O}_{2 \max},$$ by cardiac output and oxygen extraction adaptation during intermittent versus continuous endurance training

Abstract

Improvement of exercise capacity by continuous (CT) versus interval training (IT) remains debated. We tested the hypothesis that CT and IT might improve peripheral and/or central adaptations, respectively, by randomly assigning 10 healthy subjects to two periods of 24 trainings sessions over 8 weeks in a cross-over design, separated by 12 weeks of detraining. Maximal oxygen uptake (VO2max), cardiac output (Qmax) and maximal arteriovenous oxygen difference (Da-vO2max) were obtained during an exhaustive incremental test before and after each training period. VO2max and Qmax increased only after IT (from 26.3 +/- 1.6 to 35.2 +/- 3.8 ml min(-1) kg(-1) and from 17.5 +/- 1.3 to 19.5 +/- 1.8 l min(-1), respectively; P < 0.01). Da-vO2max increased after both protocols (from 11.0 +/- 0.8 to 12.7 +/- 1.0; P < 0.01 and from 11.0 +/- 0.8 to 12.1 +/- 1.0 ml 100 ml(-1), P < 0.05 in CT and IT, respectively). At submaximal intensity a significant rightward shift of the Q/Da-vO2 relationship appeared only after CT. These results suggest that in isoenergetic training, central and peripheral adaptations in oxygen transport and utilization are training-modality dependant. IT improves both central and peripheral components of Da-vO2max whereas CT is mainly associated with greater oxygen extraction.

Solving the Fick principle using whole body measurements does not discriminate “central” and “peripheral” adaptations to training

“…Daussin et al (2007) reported that interval training increased _ VO 2 max À Á from 26.3 to 35.2 ml min -1 kg -1 . At the stated body mass of 73 kg this corresponds to absolute _ VO 2 max À Á values of 1.92 l O 2 min -1 pre-and 2.57 l O 2 min -1 post-training there being no change in body mass recorded.…”

Interval versus Continuous Training

“…As a consequence, there is greater functional improvement in both the muscle and cardiorespiratory system. Daussin et al [9,10], found that interval training in sedentary subjects, improved both central and peripheral components of oxygen consumption (VO 2max ), while continuous training was associated with greater O 2 extraction. Interval training, is also beneficial for highly trained athletes, who difficult enhance further endurance performance.…”

High-Intensity Intermittent Exercise Training for Cardiovascular Disease

“…The magnitude of health benefits provided by exercise programs depends mainly on exercise intensity and volume. Based on the concept of a positive continuum of health/fitness benefits with increased exercise intensity, the old method of training applied for athletes [16] "the interval training" had been used to improve aerobic power and causes metabolic adaptations in sedentary healthy individuals and recreationally active adults [17][18][19][20][21][22][23]. In recent years, it has also been used as an effective method to improve functional capacity, cardiac function and peripheral muscular adaptation in cardiac patients [24][25][26][27].…”