How to measure aerobic intensity

     I should give you a warning about this post.

It requires a little math.

Still with me?

GOOD!

    Think about when you're running. How do you know if you're running at the right pace? If you're like me the pace varies throughout the run. I'll come out of the gate strong, hit a little wall, re-group, maintain a decent pace then try and sprint at the end. The average pace is what I want, but the pace is all over the place. We know that maintaining a certain pace throughout aerobic training provides different adaptations. Long, Slow, distance acclimates the body to the distance required for the event, Pace/Tempo training trains our anaerobic system in order to push our lactate threshold to the right, HIIT training builds speed for the end of the race, and fartlek training breaks up the monotony of distance running. Bouncing from various paces does have value, but is it the adaptation that I want? Juding pace and using pace is valid form. It does take time and discipline to fine tuning pace running.

    Along with pace we can use Rate of Perceived Exertion (RPE) for our aerobic training. RPE is a chart from 1-10 in terms of how hard something is. For example, a 1 is nothing and 10 Deadpool training (Maximum effort). There is variability when it comes to RPE-its subjective. To a novice runner just starting out two miles can be a 7 or 8 while a marathon runner is just getting started at two miles. External factors can play a part in RPE as well. Weather being a prime example. Hot, humid environments can play mental games in our heads while running. Why I'm I out here in the heat of the day? We all can't be David Goggins and block out the weather. The boredom of running indoors on a treadmill can mess with our mental state as well. Generally, music can help out but what if your running test prevents music? RPE is valid but as you can see it has several variabilities and is completely subjective.

    Wait a second. You said that we would be doing math? I did say that. Thanks for being patient. We are about to get into it. A third way to measure aerobic intensity is using heart rate. Heart rate is the most frequently used method of measuring intensity. I should preface that there is one variability pertaining towards heart rate-Age. With age, we can tailor our workouts across the board to the individual runner. Ready to use some math? No? too bad here it is. 

    If you want to use heart rate to measure intensity, then consider the Karvonen Method. The Karvonen method is a series of formulas to determine intensity. It starts with Age Predicated Maximum Heart Rate (APMHR) (220-age). Easy-peasy so far. Once we determine the APMHR we subtract our resting heart rate. Not sure how to find your resting heart rate? I got you I got you. Find your pulse, set a ten second timer, count your pulse then multiply by six. Take that number and subtract that from your APMHR. That number is your Heart rate reserve (HRR). The next step is to figure out the intensity that you want to run at. Lets say I want to run between 60%-70% of VO2 max. I take my HRR and multiply by .60 and .70 then add my RHR back into the formula and that is my Target Heart Rate Range. 

Lost? 

I'll break it down

APMHR (220-age)

HRR (APMHR-RHR)

THR (HRR x intensity) + RHR

THRR

Still lost?

Let's do an example

    Premise: 37-year-old that wants to run at 60%-70% of Vo2 Max with a resting heart rate of 60.

APMHR (220-37=183)

HRR (183-60=123)

THR (123x.60=73.8 (74) and 123x.70=86.1(86)) + 60=134-146

    All this means is that in order to stay within the intensity range allocated heart rate needs to be within 134 and 146 beats per min. Most fitness watches track heart rate (you may have to set the watch face to display that data). Once that is complete then it is easy to look down at the watch during the run and maintain that range. Personally, I would pick a number in the middle and do my best to stay at that number to ensure I am in range. For this set of data, I would set a goal of 140 with a plus or minus of 5 to be within range. This style takes a little homework, but it will ensure you are running at the intensity that you want. You can always to the math while you're prepping for the run. While you're eating your banana and sipping on your water you can do this simple math then go out and have a game plan for your run instead of frolicking all about.