Our hypothesis is that the linear extrapolation of PS SmO2 during the work stage can predict time to exhaustion, when performed to task intolerance. Across both male and female subjects, we have seen that in 27 of 36 trials, both the vastus lateralis and paraspinals oxygenation slopes provide a reasonable prediction of TTE.
The next generation approach to metabolic profiling and training prescription will almost certainly not include breakpoints or thresholds at all, and will use more flexible methods of describing continuous physiological response profiles in real-time. I think that by defining the rules which our brains are already using to find patterns, we will be able to better understand the real physiological relationships for an individual athlete, and improve how we can apply insights to that individual athlete's training.
Muscle Oxygenation refers to the flux of oxygen within a target tissue as the result of oxidative respiration. Delivery of oxygenated blood from the heart & lungs and uptake or extraction of oxygen by the mitochondria within the local muscle. This is measured with a technology called near-infrared spectroscopy (NIRS)
A recent finding in our research with Moxy muscle oxygenation was looking at the reliability & repeatability of muscle oxygen saturation (SmO2) compared to heart rate for a typical high intensity interval workout. We had a group of well-trained male subjects (VO2max > 60 ml/kg/min) perform a series of 4x4min high intensity
For this experiment we wanted to look at physiological response to the same workout in the LAB vs in the FIELD. It's fascinating! There are a lot of conflicting and equivocal findings, ultimately suggesting that there is a high degree of individual variability in how each of us produce power across modalities and conditions.