5 Interesting Results from my Walk/Run Experiment

How many of you read our 6 Reason Why the Walk/Run Method May Be For You blog with a little bit of skepticism? I know when I first started researching the idea, I approached it with quite a bit of doubt because the common sense of it told me, I’d run faster and longer if I rate at a slow, consistent rate. When I read up on the concept, I was somewhat swayed by the arguments but, truth be told, I really wasn’t sold. 

But, I’m one of those athletes that has been injury prone for most of my life; I tore my right hamstring in Middle School, training for the Regional Track meet (a little brag here, I had won the District Meet in the 400 meter dash); I then tore that same hamstring playing baseball the following year; and, to add insult to injury I then ruptured my Achilles Tendon playing basketball in my late 20’s. 

As I took up distance running as I got older, I tended to have calf strains primarily which seemed to happen later in my runs and, in particular, during my long runs. So, this research was about self-survival as a runner entering his 60’s but I determined the research was based on large groups of people and I wanted to know how it would impact ME! 

Thus, began my great Walk/Run Experiment of March 2020 and, while it seemed the walk/run days were easier, the results I tracked on my Garmin Forerunner were incredible and I wanted to share the 5 most interesting results. 

I set up the experiment over a 2 week period of time from March 11^th through March 25^th and ran every day during this timeframe (more on this later, I may actually extend this and run every day for the next year using the walk/run method). These runs were anywhere from 2 miles to 7 miles in length, and my average pace was around 11 minutes per mile; so, whether it was a continuous run or a walk/run combo my average pace was close to 11 minutes. 

I ran 3 “control” runs, each of them continuous runs of 2, 3 and 4 miles and then walk/ran eleven times, anywhere between 3 miles and 7 miles; again, with each of these at around 11 minutes per mile. For each run, I tracked my Perceived Effort, Calories Burned Per Mile, Average Heart Rate and Max Heart Rate. 

Perceived Effort

I like this method of analyzing my runs, since it allows me to assess how my body feels and I’ll look at my perceived effort during the run, at the end of my run (how easy it would be to continue) and after my run (ease of recovery). 

For this, I use the revised Borg Rate of Perceived Exhaustion scale which allows you to assess your activity on a 0 – 10 point scale from nothing to exhaustion. Self-assessment is one of the best ways to determine effort, as you are most acutely aware of how your body feels during your run. See the RPE Scale below.

Since I kept my pace at a relatively slow rate of 11 minutes per mile, regardless of whether the run was a continuous run or a walk/run my perceived effort was relatively low on the scale; however, there was a clear distinction between my continuous runs and my walk/run efforts. My walk/run efforts averaged a 2.8 on the RPE scale, which was 23% better then the 3.7 for my continuous runs. 

In addition, I kept a journal on all of these runs and paid particular attention to how I felt at the end of the run and whether I felt I could continue at the given pace and there was a distinct difference. With my walk/run, even at the longer distances my body felt as if I could continue at that pace indefinitely…I just felt no fatigue whatsoever while there was some fatigue at the end of even my shortest continuous run. 

Calories Per Mile

One of the ways I try to determine how efficient I’m running and how soon fatigue might set in is to track the number of calories I burn per mile (it’s also a great way to assess how much hydration and nutrition needed during a longer run). How many calories you burn is driven by many factors, such as age, weight, gender, genetics, fitness level and intensity. 

Since none of these factors changed during my run other than the intensity level of the run much of which is driven by how efficiently I’m running. If you read our Walk/Run blog, you remember one of the advantages of the walk/run method is it allows you to maintain your running form easier increasing your running efficiency (which may break down more during a continuous run). 

The results of my experiment were interesting, and my calories burned per mile for my walk/run efforts was 89 while the calories burned during my continuous runs was 108 or 18% higher than my walk/run results. Clearly, I was moving more efficiently during my walk/run efforts, burning less calories per mile and pushing back the point of fatigue onset. 

An interesting point here, my two longest runs of 6 and 7 miles showed me burning calories at a better than average rate as compared to all of my walk/run efforts; it appears the longer I run, the more efficient I am and the less calories burned per mile.   

Average Heart Rate

Obviously, tracking your heart rate is an excellent way of assessing the effort of a run and I looked at both my Average Heart Rate and my Maximum Heart Rate as part of this experiment. My Average Heart Rate during my walk/run efforts was 139, while my Average Heart Rate during my continuous runs was 160; this is a 13% difference, which is significant. 

Maximum Heart Rate

My Max Heart Rate during my walk/run efforts was, on average across all walk/run efforts 163 beats per minute while my Max Heart Rate during my continuous runs was 177 (if you don’t consider my one 2 mile continuous run, it was actually 182) beats per minute. 

Check out the two graphs below; which are both from a 3-mile effort, the first is a 3-mile continuous run and the second is a 3-mile walk/run. You’ll notice a few things: 

• During the second half of the continuous run, my Max Heart Rate exceeds 160 for most of the time and towards the end stays at or above 170
• With my walk/run, you’ll see my heart rate drop during the walk portions but, other than the one spike above 160 you don’t see the cumulative impact of an increasing heart rate; my conclusion is the walk portion lowered my heart rate, and allowed it to maintain more evenly over the course of the run

Longer Distance Impact

One thing that became clear to me during this two-week period was the longer the run, the better I felt which seemed contradictory to me. So, I checked out my Garmin results and found the following to be true. 

My calories burned per mile for my 7 mile walk/run was 83 (the second lowest of any of the 14 runs done during this period); my Average Heart Rate was 136 (the third lowest of the 14 runs) and my Max Heart Rate was 156 (also, the third lowest of the 14 runs). All of this despite the fact it was the longest of all my runs during the experiment. 

Check out the Heart Rate graph below for my 7 mile run, and you’ll see I barely went over 150 beats per minute compared to my 3 mile walk run (over 160 beats per minute) and my 3 mile continuous run (over 180 beats per minute.

It seems the longer I went, the more efficient I ran, and the less effort required.

As an FYI, below is the spreadsheet showing all my runs and the results from my Garmin as well as my Rate of Perceived Effort.

My plan is to slowly increase my long runs and track the results to see how far this anomaly continues; stay tuned, I’ll let you know how it goes.