JOURNAL ARTICLE

A "Step-Ramp-Step" Protocol to Identify the Maximal Metabolic Steady State

Danilo Iannetta, Erin Calaine Inglis, Silvia Pogliaghi, Juan M Murias, Daniel A Keir
Medicine and Science in Sports and Exercise 2020 March 20
32205678

The oxygen uptake (V[Combining Dot Above]O2) at the respiratory compensation point (RCP) closely identifies with the maximal metabolic steady-state. However, the power output (PO) at RCP cannot be determined from contemporary ramp-incremental exercise protocols.

PURPOSE: To test the efficacy of a "step-ramp-step" (SRS) cycling protocol for estimating the PO at RCP and the validity of RCP as a maximal metabolic steady-state surrogate.

METHODS: 10 heathy volunteers (5 women; age: 30±7 yr; V[Combining Dot Above]O2max: 54±6 mL·kg·min) performed in series a: moderate step-transition to 100 W (MOD); ramp (30 W·min); and, after 30 min of recovery, step-transition at ~50% peak PO (HVY). Ventilatory and gas exchange data from the ramp were used to identify the V[Combining Dot Above]O2 at lactate threshold (LT) and RCP. The PO at LT was determined by linear regression of the V[Combining Dot Above]O2 versus PO relationship after adjusting ramp data by the difference between the ramp-PO at the steady-state V[Combining Dot Above]O2 from MOD and 100 W. Linear regression between the V[Combining Dot Above]O2-PO values associated with LT and HVY provided, by extrapolation, the PO at RCP. Participants then performed 30 min constant-power tests at the SRS-estimated RCP and 5% above this PO.

RESULTS: All participants completed 30 min of constant-power exercise at the SRS-estimated RCP achieving steady-state in V[Combining Dot Above]O2 of 3176±595 mL·min that was not different (p=0.80) from the ramp-identified RCP (3095±570 mL·min) and highly consistent within-participants (bias=-26 mL·min; r=0.97; CV=2.3±2.8%). At 5% above the SRS-estimated RCP, four participants could not complete 30 min and all but two exhibited non-steady-state responses in blood lactate and V[Combining Dot Above]O2.

CONCLUSIONS: In healthy individuals cycling at their preferred cadence, the SRS protocol and RCP are capable of accurately predicting the PO associated with maximal metabolic steady-state.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
32205678
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"