The past week or so, I've been talking about running cadence with a friend of mine. He's starting a new running program, and one of the main concepts is cadence - or how fast your feet turnover during running. According to multiple sources (Galloway, Daniels, etc) - a cadence of 180 footstrokes per minute (90 per foot per minute) is considered optimal.
Over this past winter, I toyed around with cadence a bit - only to the extent that a few times I tried to increase it to see what it felt like, but didn't pay a whole lot of attention to it. The Galloway program includes cadence drills, but for some reason I had been kinda neglecting them. I assumed that my cadence was about average, and I assumed that the average was around 120 footstrokes per minute (60 per foot per minute).
After hearing my friend talk about his work to increase cadence (as he put, 90 per foot per minute is 'friggin fast', and he felt like he was gliding) - I thought I might take a look at cadence again. With the two runs this week being easy workouts, followed by a 17 miler this weekend, I figured this would be a good time to work on it. I'd have two 45 minute sessions this week, and a nice long run to really nail the rhythm down. At the very least, I could get a good sense of what 90 strokes per foot per minute felt like - and even if it wasn't something I could attain right away - it'd be a start.
So today I started off, and decided I'd jog naturally and determine my cadence - just to see where in the ballpark I was. So I counted left foot strokes, and after 60 seconds I came up with.... 82.
Wha?
That's quite a bit different than I thought I'd be at (60), and a LOT closer to the optimum than I thought I was at! Huh...
So I continued for a couple miles - I timed myself multiple times, each time ending up right around 85, after consciously increasing cadence ever so slightly after that initial reading.
I then decided to see how stride length, while keeping cadence, would affect heartrate. Since this was to be an easy run, I tried to target my long slow run HR of 150 bpm. I found it actually quite difficult - as I could barely manage to keep it as low as 153. So I tried to shorten my stride length to compensate. Although my first two miles were done in 17:05 with an avg HR of 151, that 151 takes into account the start up from walking HR - so its a bit deceiving.
For mile #3, I decided I'd maintain cadence and shorten my stride as much as I could to keep my HR down around 150, and then see what the time was. The avg HR was 155, and my time for the mile was 9:37. It was becoming obvious that although the cadence only felt slightly faster than normal, it was difficult for me to maintain a low heartrate. I'm not sure whether it was due to not being fully recovered from Sunday's triathlon, or whether there is a certain degree of overhead with a high turnover that a short stride length cannot fully compensate for.
For mile #4, I did the same thing - trying to keep cadence and shorten stride to maintain 150. However, this mile included some slight uphill. The result was 1 mile in 9:15, with an avg HR of 156.
For a portion of mile #5, I decided to check out the resultant HR when maintaining the same cadence, but increasing stride length. I did this for 1 minute, and my HR got into the 170's. Unfortunately, I didn't get a mark of where that 1 minute at a higher pace brought me to - so I have no information to extrapolate what my mile time would be. Since the 85 cadence is not much faster than what feels natural - I figure it'll be easy enough during a mile repeat or speed workout session to see what kind of pace I can manage.
During the rest of mile #5, I toyed around with different things to see if I could get my HR back down to 150. I tried the 85-90 cadence with very short stride lengths, as well as trying to revert to a slower cadence and pace - possibly one that I used to run when I started running again last year (although its been long enough that I cannot really recall too well).
It was definately interesting. Anytime I went to a 'slower' cadence (which turned out to be 75 or so), I found myself bouncing up in the air quite a bit. I'm not really sure what a cadence of 60, what I thought I was closer to, would feel like. It'd either have to be a stride length that would be very unnatural for me, or so much bouncing that.. well, it'd just be rediculous. Considering how 'bouncy' the cadence of 75 was, I can definately see where 85-90 is, by comparison, like 'gliding'. It just seems that when cadence is > 80, more effort goes towards forward movement - and when it is < 80, a significant degree of the effort expended ends up going towards vertical motion - which is wasteful.
In trying to figure out why my cadence was in the 80's to begin with - I can think of only one reason. Although I've largely ignored cadence for a while, one thing I haven't ignored is foot placement when landing. I've made a good amount of conscious effort over the months to avoid landing on my heel, and concentrating on landing on my mid-foot. In order to do this, the leg being landed on cannot extend to far ahead of the body. This results in a shorter stride length, and I think that I've been unconsciously increasing cadence to compensate for this - to the point where anything less than 80 footstrokes per foot per minute seems unnatural. Unfortunately, I have NO cadence information from before I started consciously trying to keep from landing on my heel - so the whole theory might be a crock.
The other thing is that although 85 is only slightly faster than the 'natural' cadence of 82 that I found myself using initially, I still have to work on getting an extra 5 footstrokes per foot per minute in there. It may not sound like much (until I started writing this, that is what I thought) - but considering that 75-76 feels completely different than 85, I'm sure that 85 feels completely different from 90.
Total Distance: 5.25 miles
Avg HR: 155
Total Time: 48:30
No comments:
Post a Comment