Systematic analysis of adaptations in aerobic capacity and submaximal energy metabolism provides a unique insight into determinants of human aerobic performance.

“Previously, it has been concluded that V˙ O 2max sets the upper limit for aerobic performance (3, 11), but this has little relevance for maximal work performance over extended durations, where it is not possible to maintain exercise at V˙ O 2max .”

“A high V̇O2max is associated with reduced risk of metabolic and cardiovascular disease (9, 35, 50), and training-induced changes in V̇O2max have been shown to correlate with changes in risk factors for metabolic and cardiovascular disease and mortality (29, 51).”

“The potential for metabolic-responsive processes such as calcium-mediated signaling (8) or AMPK activation (32) as mediators of adaptations in aerobic performance would be consistent with our present analysis.”

“Indeed, the fact that some individuals do not improve V˙ O 2max in response to a standardized aerobic training program has been known for over two decades (25, 39) and was convincingly demonstrated by Bouchard et al. (6) in a large cohort in the HERITAGE Family Study.”

“In support of this view, V˙ O 2max and aerobic performance are positively correlated in athletes of mixed ability (15, 24, 27, 42), with well-trained endurance athletes achieving values for V˙ O 2max over twice those of sedentary individuals (42).”

“…a training effect in endurance training studies (3), and V˙ O 2max is often used to quantify and standardize exercise intensity for training studies (13, 18, 38), submaximal time-to-exhaustion performance trials (28, 37), and studying metabolic responses to submaximal exercise (1, 41).”

“Previously, it has been concluded that V˙ O 2max sets the upper limit for aerobic performance (3, 11), but this has little relevance for maximal work performance over extended durations, where it is not possible to maintain exercise at V˙ O 2max .”

“The link between V˙ O 2max and aerobic performance is deemed strong enough for researchers to search specifically for training techniques optimizing increases in V˙ O 2max to improve performance (31).”

“Conversely, oxygen-related processes such as HIF-1 (cid:9) (2) and VEGF signaling promoting vascular remodeling (19) would seem less likely determinants of gains in functional capacity, but may be central for improvements in aerobic capacity (47).”

“…a training effect in endurance training studies (3), and V˙ O 2max is often used to quantify and standardize exercise intensity for training studies (13, 18, 38), submaximal time-to-exhaustion performance trials (28, 37), and studying metabolic responses to submaximal exercise (1, 41).”

“…a training effect in endurance training studies (3), and V˙ O 2max is often used to quantify and standardize exercise intensity for training studies (13, 18, 38), submaximal time-to-exhaustion performance trials (28, 37), and studying metabolic responses to submaximal exercise (1, 41).”

“Numerous authors have focused on the average improvement in a range of classic parameters altered by aerobic training (12, 34, 38, 44), yet when one examines the data closely most of these parameters show no sign of change in a proportion of subjects (Fig.”

“However, in well-trained athletes V˙ O 2max remains stable even when performance is shown to increase (3, 4), and in these athletes the correlation between V˙ O 2max and aerobic performance can be poor (10, 26).”

“However, in well-trained athletes V˙ O 2max remains stable even when performance is shown to increase (3, 4), and in these athletes the correlation between V˙ O 2max and aerobic performance can be poor (10, 26).”

“Indeed, the fact that some individuals do not improve V˙ O 2max in response to a standardized aerobic training program has been known for over two decades (25, 39) and was convincingly demonstrated by Bouchard et al. (6) in a large cohort in the HERITAGE Family Study.”

“2 M KCHO3 and used for spectrophotometric determination of ATP, PCr, and lactate (21) and for the determination of free carnitine and acetyl-carnitine (ALCAR) by enzymatic assays using radioisotopic substrates (7).”

“Molecular responses to the exercise training program have been reported elsewhere (22, 47, 48).”

“Indeed, the fact that some individuals do not improve V˙ O 2max in response to a standardized aerobic training program has been known for over two decades (25, 39) and was convincingly demonstrated by Bouchard et al. (6) in a large cohort in the HERITAGE Family Study.”

“Conversely, oxygen-related processes such as HIF1α (2) and VEGF signaling promoting vascular remodeling (19) would seem less likely determinants of gains in functional capacity, but may be central for improvements in aerobic capacity (47).”

“…previous work suggesting a correlation between training-induced improvements in V˙ O 2max and beneficial effects on risk factors of metabolic and cardiovascular disease (29, 51) our observations have potential implications in the search for the mechanisms by which aerobic exercise improves health.”

“Finally, Smith et al. (43) showed a significant positive correlation ( r 2 (cid”

“…a training effect in endurance training studies (3), and V˙ O 2max is often used to quantify and standardize exercise intensity for training studies (13, 18, 38), submaximal time-to-exhaustion performance trials (28, 37), and studying metabolic responses to submaximal exercise (1, 41).”

“In support of this view, V˙ O 2max and aerobic performance are positively correlated in athletes of mixed ability (15, 24, 27, 42), with well-trained endurance athletes achieving values for V˙ O 2max over twice those of sedentary individuals (42).”

“As maximal aerobic performance relies on a percentage of V˙ O 2max , this implies an “over capac-ity” of the aerobic system’s ability to transport oxygen, which can only be used for short periods of time under conditions usually incorrectly referred to as “anaerobic” (45, 46).”

“In support of this view, V˙ O 2max and aerobic performance are positively correlated in athletes of mixed ability (15, 24, 27, 42), with well-trained endurance athletes achieving values for V˙ O 2max over twice those of sedentary individuals (42).”

“Indeed, studies using chronic obstructive pulmonary disease patients (33), recre-ationally active subjects (20, 40), and endurance-trained athletes (5, 23) did not observe a correlation between the magnitude of training-induced improvements in (cid:1) V˙ O 2max and aerobic performance.”

“Indeed, studies using chronic obstructive pulmonary disease patients (33), recre-ationally active subjects (20, 40), and endurance-trained athletes (5, 23) did not observe a correlation between the magnitude of training-induced improvements in (cid:1) V˙ O 2max and aerobic performance.”

“In support of this view, V˙ O 2max and aerobic performance are positively correlated in athletes of mixed ability (15, 24, 27, 42), with well-trained endurance athletes achieving values for V˙ O 2max over twice those of sedentary individuals (42).”

“Therefore, as others have suggested (17, 30), the present study demonstrates that V˙ O 2max cannot be considered a universal parameter to stan-dardize aerobic exercise training studies.”

“Indeed, studies using chronic obstructive pulmonary disease patients (33), recre-ationally active subjects (20, 40), and endurance-trained athletes (5, 23) did not observe a correlation between the magnitude of training-induced improvements in (cid:1) V˙ O 2max and aerobic performance.”

“…a training effect in endurance training studies (3), and V˙ O 2max is often used to quantify and standardize exercise intensity for training studies (13, 18, 38), submaximal time-to-exhaustion performance trials (28, 37), and studying metabolic responses to submaximal exercise (1, 41).”

“Activities of citrate synthase (CS), complex I (CI), and complex IV (CIV) were determined as previously described (16).”

“Indeed, studies using chronic obstructive pulmonary disease patients (33), recre-ationally active subjects (20, 40), and endurance-trained athletes (5, 23) did not observe a correlation between the magnitude of training-induced improvements in (cid:1) V˙ O 2max and aerobic performance.”

“A high V̇O2max is associated with reduced risk of metabolic and cardiovascular disease (9, 35, 50), and training-induced changes in V̇O2max have been shown to correlate with changes in risk factors for metabolic and cardiovascular disease and mortality (29, 51).”

“Numerous authors have focused on the average improvement in a range of classic parameters altered by aerobic training (12, 34, 38, 44), yet when one examines the data closely most of these parameters show no sign of change in a proportion of subjects (Fig.”

“…in whole-body aerobic fitness measured by maximal oxygen uptake (VO2max), and reflect enhancements in the intrinsic oxidative capacity of muscle, and the delivery and utilization of substrates in working muscle during subsequent exercise bouts (Phillips et al., 1996; Vollaard et al., 2009).”

“Consequently, despite our limited understanding of the dose-response relationship between the training load and training-induced changes in physical capacities and performance (which generally shows large inter-individual responses [19, 20]), there has been a growing interest by the sport science community for charact…”

“23 In addition, from a conceptual point of view, there are additional advantages in integrating internal and external load measures for monitoring training.”

“responses [19, 20]), there has been a growing interest by the sport science community for characterizing training protocols that allow athletes to maintain the longest time [90 % _ VO2max (T@ _ VO2max; see Midgley and McNaughton [14] for review).”