Fig 1.
Experimental Visit Exercise Dose Protocol.
Participants will perform a total of 10 experimental visits. N = 4 will be dedicated to the manipulation of exercise duration (i.e., variable duration at a constant intensity, blue box), N = 4 will be dedicated to the manipulation of exercise intensity (i.e., variable intensity at a constant duration, green box), and N = 2 will examine the impact of differential exercise modalities (i.e., up-right cycle ergometer, red box).
Fig 2.
Sequence of Experimental Visits.
Following the baseline visit (black box), participants will be following the sequence of experimental visits shown here. Experimental sessions designed to manipulate exercise duration (blue boxes) will be conducted on the treadmill for: 1.) 10 min, 2.) 20 min, 3.) 30 min, and 4.) 60 min at a fixed exercise intensity of V̇O2 = VT1–15%. Experimental sessions designed to manipulate exercise intensity (green boxes) will consist of variable intensity treadmill walking/running at V̇O2 = 1.) VT1-30%, 2.) VT1-15%, 3.) VT1, and 4.) VT1 + 15% for a fixed duration of 30 min. Modality manipulation (red boxes) will include up-right cycling for 30 min at V̇O2 = VT1-30% and VT1-15%. * = Direct comparisons to examine differential biochemical responses to running/walking and cycling exercises. VT1 = The first ventilatory threshold.
Fig 3.
Hypothetical molecular exercise dose-response profiles.
It is anticipated that the majority of plasma-based molecules will adhere to one of 3 primary exercise dose-response profiles: Unresponsive to exercise (A), Up-regulated by exercise (B), or Down-regulated by exercise (C).