A modified step–ramp–step protocol to prescribe constant-speed exercise in treadmill running

• Published in: European journal of applied physiology Vol. 124; no. 11; pp. 3445 - 3455
• Main Authors: Faricier, Robin, Micheli, Lorenzo, Guluzade, Nasimi A., Murias, Juan M., Keir, Daniel A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2024; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biomedicine; Fitness equipment; Human Physiology; Occupational Medicine/Industrial Medicine; Original Article; Running; Sports Medicine; Gas exchange threshold; Respiratory compensation point; Incremental exercise; Exercise prescription
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-024-05542-y

Purpose
This study investigated whether a running-adapted version of the cycling-based “step–ramp–step” (SRS) protocol would improve prediction of
V
˙
O
2
in treadmill exercise compared to the traditional prescriptive approach.
Methods
Fourteen healthy individuals (6 females; 25 ± 6 years; 66.1 ± 12.7 kg) performed a treadmill-based SRS protocol including a ramp-incremental test to task failure followed by two constant-speed bouts within the moderate-(MOD
step
—below estimated lactate threshold;
θ
LT
), and heavy-intensity domains (HVY
step
—between
θ
LT
and respiratory compensation point; RCP). Using the uncorrected
V
˙
O
2
-to-speed relationship from the ramp exercise, three constant-speed bouts were performed at 40–50% between: baseline and
θ
LT
(CSE
MOD
);
θ
LT
and RCP (CSE
HVY
); and RCP and peak (CSE
SEV
). For CSE
MOD
, CSE
HVY
, and CSE
SEV
measured end-exercise
V
˙
O
2
was compared to predicted
V
˙
O
2
based on the: (i) “SRS-corrected”
V
˙
O
2
-to-speed relationship (where MOD
step
and HVY
step
were used to adjust the
V
˙
O
2
relative to speed); and (ii) linear “uncorrected” data.
Results
Average treadmill speeds for CSE
MOD
and CSE
HVY
were 7.8 ± 0.8 and 11.0 ± 1.4 km·h
−1
, respectively, eliciting end-exercise
V
˙
O
2
of 1979 ± 390 and 2574 ± 540 mL·min
−1
. End-exercise
V
˙
O
2
values were not different compared to SRS-predicted
V
˙
O
2
at CSE
MOD
(mean difference: 5 ± 166 mL·min
−1
;
p
 = 0.912) and CSE
HVY
(20 ± 128 mL·min
−1
;
p
 = 0.568). The linear “uncorrected” estimates were not different for CSE
MOD
(− 91 ± 172 mL·min
−1
;
p
 = 0.068) but lower for CSE
HVY
(− 195 ± 146 mL·min
−1
;
p
 < 0.001). For CSE
SEV
(running speed: 13.8 ± 1.7 km·h
−1
), the end-exercise
V
˙
O
2
was not different from peak
V
˙
O
2
achieved during the ramp (3027 ± 682 vs. 2979 ± 655 mL·min
−1
;
p
 = 0.231).
Conclusion
In healthy individuals, the SRS protocol more accurately predicts speeds for a target
V
˙
O
2
compared to traditional approaches.