Good Better Best, Interval Training Done Right part Deux (that’s Fancy for 2)


While HR Zones is a much better and objective measurement than feel, it is certainly not the best metric at our disposal. The reason it is not the top of is because it is an extrapolation derived hopefully from accurate metabolic testing, not math. The only way to know your TRUE HR Zones is to test using devices built for testing VO2 Max etc. Once you know your HR Zones you are on your way. Except, that they might not always be exactly the same from day to day, week to week or month to month. As your fitness increases/decreases the initial HR Zones may no longer apply. Even worse you wouldn’t know until the next time you test and establish your up to date HR Zones.

This could result in various training session that missed the point or were not as efficient at eliciting the intended stimulus as we hoped for.


This leads us to probably the best way to truly know if you are pushing your physiology on any given day to any given stimulus; NIRS. Near-Infrared Spectroscopy or NIRS is utilized in measuring SmO2% at the primary working muscle or secondary muscles to determine a whole host of limitations. It can also be utilized on a daily basis to measure muscle saturation/desaturation during training intervals.


In steps MOXY (Muscle Oxygen Monitor). Why would we want t monitor the amount of oxygen consumption during exercise? Oxygen transportation and utilization is critical in determining athletic capacity. MOXY allows us to measure the SmO2 optically with Near Infrared Light and as such is completely non-invasive.

Much of the work we do during whether intervals of high intensity of high load movement such as 1 rep max lifts our musculature is dependent on the creation of ATP (Adenosine Triphosphate). We primarily are creating ATP utilizing on Phosphocreatine (PCr) energy system in order to maintain cellular balance. To accomplish the replenishment of this energy system O2 is necessary. Muscle oxygenation almost immediately responds to the onset of exercise, indicating that high intensity training is correlated to oxygen availability in the muscle.

So, why is MOXY the best method for guiding interval training? Simply put by identifying SmO2 for that training session we are able to utilize real time biofeedback data to determine training intensity, recovery and duration.

The Training Session

What might a MOXY Interval training session look like? After completing a thorough warm up in which we push SmO2 as high as possible (70-90%) we are able to establish parameters for the training intervals. I’ll cover in closer detail a proper warm up utilizing MOXY. The first % achieved during the warm up is your ‘recovery baseline’ this is the % we would want to return to after the high intensity intervals. Then we need to determine our ‘performance baseline’ this will be our minimum SmO2 reached during the strenuous high intensity work.

Once these 2 primary parameters are establish we can build our training intervals based on SMo2 with proper recovery to ensure that we can come back to baseline or Complete Recovery after each interval work load. This allows for us to accurately determine when the athlete is ‘ready’ to perform the next interval in optimal condition. This ensures that we are able to get the most out of each interval set without wasting energy or time.

Example Training Session

So back to our example Echo Bike training session. Now we will look at how we would accomplish it with MOXY. after warm up we establish the athlete to have a Recovery Baseline SmO2 of 80%. We establish after a high intensity sprint n the Echo Bike that the athlete is able to ‘desaturate’ to SmO2 of 30% or their Performance Baseline..

We can now build the training session as follows:

8 x Max Intensity Echo Bike to 30% SmO2 or within 10% of that Performance Baseline.

The next interval DOES NOT begin until the athlete has reached the Recovery Baseline of 80% or within 10% of that baseline.

The athlete will continue doing the interval training until the 8 intervals are completed or they are no longer able to get within 10% of the recovery or performance baseline.

Do we always have to recover back to baseline? Absolutely not. This would take away all variance in the physiologic realm. There are actually 4 recovery protocols that Ill cover in a future blog (Hypoxic, Complete, Incomplete, Enhanced). Stay Tuned.