BACKGROUND: Heart rate does not quantify the actual load. It quantifies the total stress on the individual. The longer the work period, the more closely heart rate quantifies the load. The shorter the work period, the less it quantifies the load.

So for EMOM training, although your heart rate monitor may say that you’re in Zone 2 the whole time, I suspect very little of the workout was in Zone 2. You were either way above, or way below, and the average of the work/rest periods creates a stress load equivalent to what an extended period in Zone 2 would be like.

Same level of stress on the body. Very different levels of stress on the muscles.

In other words, 45′ of EMOM in the gym will not help your running as much as 45′ on the trail. Or vice versa. I don’t think there’s any harm to it, as long as you think of the two activities as distinct.

Does that make sense?

Mike,

Thanks for the read and the questions. Scott nailed it on the head when considering the nuances of Zone Training in a timed environment. I’ll take it a step further from a tactical perspective and hopefully provide some solutions to your training question.

Some science:
While HR Zones have been shown to be an effective measure of training intensity when looking at cyclical work (i.e running, rowing, cycling), the Zone model is considerably less effective when applied to what I would call “mixed modal” work (i.e. wall balls, pull ups, barbell work, etc.). To understand why, we have to look at the physiology of oxygen and the muscles. When you begin any activity, oxygen saturation immediately increases in the working muscle to account for the demand of the activity. This physiological response happens much faster than what is reflected by an increased heart rate (i.e. cardiac lag), meaning that although you hold yourself in an “aerobic” zone on the HR monitor, your muscles may actually be experiencing an “anaerobic” environment due to various physiological limitations unique to your own body.

I took you on that long scientific journey as a way of echoing Scott’s point, which is that just by “staying” in an aerobic zone doesn’t mean you’re getting a 1:1 translation to any and all aerobic activities. To the contrary, you may very well be creating a totally different adaptation without realizing it based on your own physiology.

A better solution might be to set up something like this:

40 min EMOM, rotating through the following:
Min 1) :30s Run
Min 2) :30s Row
Min 3) :30s Bike
Min 4) :30s Versaclimber

Your goal with each one of those like modalities (to guarantee an aerobic response) would be to hit the same output in whatever metric you’re using the measure. For the run, it may be meters just as for the bike and row erg it may be calories. Regardless of the metric, you want to maintain sustainability for that modality, meaning that if you hit 200m on the first :30s run your goal is to hit 200m for every subsequent run within that EMOM.

Using a similar approach for mixed modal work is excellent…for improving the aerobic nature of mixed modal work. You may experience some carryover to the mountains, but not as much as you would if you chose cyclical/sport-specific modalities instead.

Does that help?

Mike,

Turning mixed modal work aerobic is one of the harder concepts to grasp in my opinion, because through exposure to this type of training we often just assume that it’s meant to be high intensity.

It’s best to reframe your approach and think of the goal as “sustainabilty” versus just being physiologically “aerobic.” I can get waaaaay into the weeds here, so it’s probably best to put everything into a blog article and get into it there. Stay tuned!