Doing Some Math

This weekend ended up being another "test" of my ability to potentially train for a BQ type pace over the Summer. The goal was to run 21km at 4:58/km. When starting up I had visions of trying the same distance, but at 4:49/km. However, as this was my first run outside since February 1st I reserved the right to change things up while on the go. Indeed, it became very clear that it would be unrealistic for me to average 4:49/km after a first kilometre that took 5:02, even if I could have pushed it, so I decided to simply try for the 4:58/km average.

Long story short, I did complete the distance in 1:42:48, which translated to an average pace of 4:54/km. Test passed! The next day I ran an easy 4km recovery jog with my son, and today I am still feeling the effects of the weekend in the calves... Might have to stay off the planned run tomorrow and simply do some spinning. Oh well.

All that being said, today I had a closer look at my cadence metrics for the past few longer runs. Although I am not averaging the desired 180spm that so many resources tell us we should be striving for, I am pretty close and tend to average either 176spm or 178spm. This is MUCH better than a while back when I was barely hitting 170spm, so it's progress...

But something else jumped out at me while looking at these metrics. The cadence is just one of two important factors that determine performance, the other being stride length. It would seem that even if I did achieve 180spm, which has been my focus for some time now, I may still not be able to hit my desired pace to qualify for Boston if my stride length is not long enough! I quickly crunched some numbers and at a cadence of 180spm my stride length would have to be 1.234m in order to achieve a 3hr10m BQ time.

The math to achieve a 3hr10m marathon time looks like this for a few cadence options:

(178 steps/minute = 33,820 steps in 3hr10m; 42,195m divided by 33,820 steps = 1.248m/step)

(180 steps/minute = 34,200 steps in 3hr10m; 42,195m divided by 34,200 steps = 1.234m/step)

(182 steps/minute = 34,580 steps in 3hr10m; 42,195m divided by 34,580 steps = 1.220m/step)

Well, it seems that only once in my recent runs have a hit this stride length, while every other time it rests somewhere in the 1.12m/stride to 1.16m/stride range. The one time I did manage (without being aware of any of the above calculations) I averaged 178spm and my average pace was 4:34/km. That would not get me my BQ sadly, but would translate to a marathon time under 3hr15m, so that's pretty good. On another effort where I DID average 180spm my stride length was 1.20m, which translated to an average pace of 4:39/km. In other words, still too slow.

Therefore, it has become apparent to me that I need to work on my stride length and not only my turnover rate. Seems, upon cursory checking, that the only way to achieve this is to practice things like sprinting (guess they call them "strides" for a reason), improve glute strength, all the while maintaining a good turnover.

It's good to have goals...

PS: At an average stride length of 1.16m (which seems to be a reasonable number to represent my "regular" stride length), and a 180spm cadence the result would be a 3hr22m marathon. Things clearly need to change in this aspect, as well as many others no doubt...