Jem Arnold
Hard-start intervals use an initial hard effort at a power output above what would be sustainable for the intended interval duration, to enhance oxygen uptake and cardiac output. Let's talk about some of the reasons for why we might want to perform hard-start intervals, when they might be appropriate for our training, and when they might not be.
We are looking for subjects to participate in a remote cycling training study we are conducting through the University of Toronto, in partnership with TrainerRoad. This study will investigate the effects of high intensity interval training (HIIT) on cycling performance. If you are interested in participating and want more information, please go to
Here are some of my current thoughts and questions on the topic of VO2max trainability, time near VO2max, hard-start and intermittent intervals, and adaptations toward capacity and efficiency.
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
Spare Cycles 