Pulmonary O2 uptake kinetics during moderate-intensity exercise transitions initiated from low versus elevated metabolic rates: insights from manipulations in cadence

Abstract

A similar overall adjustment of [HHb] and VO₂p in LS and US across conditions suggested dynamic matching between microvascular blood flow and O₂ utilization. Prior MR (rather than external WR per se) plays a role in the dynamic adjustment of pulmonary (and muscle) VO₂p.

Mean Normalized Gain: A New Method for the Assessment of the Aerobic System Temporal Dynamics during Randomly Varying Exercise in Humans

“…Therefore, based on Figure 8, the MNG seemed to “isolate” aerobic system temporal dynamics from noise better than τ obtained from $\dot{V}{O}_2$ time-domain analysis, even after eight repetitions and filtering. In addition, in agreement with previous research (Keir et al, 2014b), the CI 95 of τ was more dependent on the number of exercise repetitions in comparison to MNG where the CI 95 was independent of exercise repetitions.…”

“…The confidence interval of the estimated τ, and therefore the “sensitivity” to identify aerobic fitness differences, depends on the $\dot{V}{O}_2$ signal-to-noise ratio (Lamarra et al, 1987; Keir et al, 2014b), the model complexity (i.e., the degree of freedom) (Motulsky and Ransnas, 1987) and the selected data window (Bell et al, 2001; Murias et al, 2011). To increase signal-to-noise ratio, studies commonly repeat similar tests multiple times within the same session (Ozyener et al, 2001; Christensen et al, 2016) or on different days (Whipp et al, 1982; Keir et al, 2014a) and average repetition-like transitions before time-domain data modeling.…”

The influence of metabolic and circulatory heterogeneity on the expression of pulmonary oxygen uptake kinetics in humans

“…; Keir et al . ). By examining a range of pretransition baseline work and metabolic rates spanning the entire moderate‐intensity domain, the present study extends previous findings to show that both and G P increase as a function of pretransition baseline WR and metabolic rate in an approximately linear manner.…”

“…; Keir et al . ). This behaviour was suggested to be evidence that kinetics do not conform to a first‐order rate reaction (Robergs, ).…”

“…Recently, Keir et al . () reported that moderate‐intensity kinetics were strongly related to baseline metabolic rate but not to the baseline WR or the magnitude of the increase in WR during the exercise bout (∆WR). This suggested that the intramuscular metabolic status (e.g.…”