Advisor: Prof. Dr. Aaron Baggish, Institute of Sport Sciences, University de Lausanne, Switzerland
Research collaboration: Dr. Philippe Hellard, Creps Aquitaine, Bordeaux France
Oxygen Kinetics at the on and offset of exercise has had researchers puzzling for decades. In practical application such as in vivo tests using a metabolic cart or VO2 analyzer, only whole body pulmonary oxygen uptake (pVO2) is accessible. Pulmonary VO2 is influence not only by muscle VO2 but also by cardiac output, blood volume, oxygenation amongst other factors. The aim of this project is to build and validate a model that discloses those factors influencing pVO2 in a quantitaive way, hence open a clearer view on pVO2 data.
Twelve healthy trained males were recruited for this project. Each of them underwent a series of load tests on a cycling ergometer (SRM high performance ergometer, 20 strain gauges powermeter version, SRM GmbH, Juelich, Germany): 1) A series of three sub-maximum efforts including pre and post efforts lactate measurements. 2) An all out seated sprint test; including pre and post efforts lactate measurements. 3) A ramp test until exhaustion, including pre and post efforts lactate measurements as well as measuring of breath by breath gas exchange. During each test power, heart rate and cadence is recorded with 1Hz.
This data is used to create a metabolic profile in INSCYD (VLamax, VO2max, MLSS, MMSS, lactate production and combustion kinetics, etc.)
Afterwards each subject undergoes three different interval trainings, on three different days in randomised order: after sufficient warm up the subjects undergo a HIT training, consisting of 4×30 at 150% of VO2max. Each on-phase is seperated by 4min recovery, using different recovery modes: 0% VO2max (=passive rest), 35% VO2max, 55% VO2max.
Power, heart rate, cadence and muscle oxygenation are recorded with 1Hz. Pulmonary gas exchange is recorded breath-by breath.
We created a computer model to simulate the dynamics of the cardiopulmonary system. The following variables are included in the model:
In a first step a metabolic profile of each subject has been generated. In a second step the recorded power times series for the three HIT Training sessions as well as the ramp test was used to model metabolic reaction as a function of the power output for each subject. With that we derive a calculated muscular VO2 (mVO2). The mVO2 is then used in the cardiopulmonary model described above to calculate pulmonary VO2 (pVO2).
The calculated pVO2 is then compared to the pVO2 measured by breath-by- breath gas exchange during the exercise.
How cycling ergometer settings in all-out sprints change power output and calculated VLamax. An INSCYD research project with Zuyd University, KU Leuven and University Hildesheim.
Modelling fat and carbohydrate use under interval and stochastic load patterns, where steady-state assumptions break down. An INSCYD research project.
VO₂max, VLamax, FatMax, thresholds, fuel use and training zones, from a single test in the lab, in the field or fully remote.
