Anyone here have the new Forerunner 620 and been toying around with the run dynamics? I have 4 outdoor runs on mine, all just under 7mi and ranging in pace from 6:30 to 7:15 (relatively steady). My cadence has generally been just under 200 and ground contact time between 210 and 220s. Those are both pretty good using to their charts as a benchmark, but my vertical oscillation has been pretty poor by comparison. I’ve gotten 8.4 twice, and the other two runs have been worse. I am not even 5’5", so I assumed my vertical oscillation would be lower by virtue of a shorter stride length.
I’m curious what other peoples’ experience has been with these features, is anyone getting markedly better vertical oscillation? Trying to figure out if I have possibly identified something that needs work (not that I would have a clue how to improve it).
The problem with intentionally reducing vertical oscillation is that it has been shown to decrease running economy. When you run faster, your contact time decreases and vertical oscillation increases. This makes sense if you think of running as a series of controlled jumps and your legs as springs (spring mass model).
I would not recommend spending your valuable training time trying to chase these metrics.
In my experience, vertical oscillation is influenced by hip rotation and ankle lean.
If you’re not rotating your hips, you’re not getting a good rearward leg extension during the pushoff. Which means you’re pushing off with your leg relatively underneath of you. This causes more of an upward bounce.
Likewise, a good ankle lean will direct more of your energy forward. Running with little ankle lean will direct more of your energy upward.
Ground contact time can mean two things, and I’m anxious to get that watch to experiment with it.
There’s ground contact time caused by landing with your foot far out in front of you. This is “wasted” time on the ground, as you can’t apply any force in that position, and you’re putting on the brakes.There’s also ground contact time caused by rotating your hips and extending your rear leg far. Up to a point, the longer you can push off, the more energy you can apply.
So absolute ground contact time (I think) wouldn’t tell you much by itself. With video analysis, you can see how much time is spent with the foot in front of you, versus time pushing off.
If you can steadily run sub-7:00/mile, I’d guess you have a fairly efficient stride already. I’d experiment with running intervals substantially faster, and also intentionally changing your hip rotation/rear leg extension to see how that changes both contact time and oscillation.
submaximal absolute oxygen cost is the only measure I know of that was used to define running economy… http://www.ncbi.nlm.nih.gov/m/pubmed/16195026/
What I currently tell patients and a good friend who just picked a garmin 620 up is the trial of miles is the best way for you to improve running economy.
It’s a great watch, and I’m really enjoying the look and feel of it (light weight, nice display, no need for foot pod). I’m in marathon mode and doing a lot of miles on the treadmill. I’ve looked at those metrics a few times, but it will be interesting to look at my data on outdoor running, hills, speed work, etc. and compare all of it. I agree with the comment about trying to reduce vertical oscillation intentionally. I kind of tried that and felt like I was “muscling” it to accomplish a lower value. My economy went down the drain.
Running 70 mpw on the hamster wheel has me thinking about all these things (it’s a lot of time alone with my thoughts!) Your comments on hip rotation and ankle lean are great, and I’ve been trying to gradually improve those things in my stride. I think the value of having the 620 is that you can incorporate some minor changes in your stride, work on it for a while, then check some of those values over time.
Thanks for the link. But that study looks at runners who were taught the Pose method. Their stride length, cadence vertical oscillation, and oxygen consumption all changed as a result of Pose-ing. So there are a lot of variables that influenced O2 consumption, not just vertical oscillation.
Do you know of any studies that looked at strong runners and had them change their vertical oscillation to see how it affected economy?
Hopefully the original poster that responded can give us links, I agree pose adds a host of variables unfortunately As I understand it Running economy is something we have identified for quite some time but have not thoughoughly studied. I am not aware of any significant studies that examine vertical oscillation and economy only.
In my experience, vertical oscillation is influenced by hip rotation and ankle lean.
If you’re not rotating your hips, you’re not getting a good rearward leg extension during the pushoff. Which means you’re pushing off with your leg relatively underneath of you. This causes more of an upward bounce.
Likewise, a good ankle lean will direct more of your energy forward. Running with little ankle lean will direct more of your energy upward.
Ground contact time can mean two things, and I’m anxious to get that watch to experiment with it.
There’s ground contact time caused by landing with your foot far out in front of you. This is “wasted” time on the ground, as you can’t apply any force in that position, and you’re putting on the brakes.There’s also ground contact time caused by rotating your hips and extending your rear leg far. Up to a point, the longer you can push off, the more energy you can apply.
So absolute ground contact time (I think) wouldn’t tell you much by itself. With video analysis, you can see how much time is spent with the foot in front of you, versus time pushing off.
If you can steadily run sub-7:00/mile, I’d guess you have a fairly efficient stride already. I’d experiment with running intervals substantially faster, and also intentionally changing your hip rotation/rear leg extension to see how that changes both contact time and oscillation.
I’d really like you to cite every statement you made in this reply. I can’t see one correct statement there.
I’d really like you to cite every statement you made in this reply. I can’t see one correct statement there.
You must have missed the part where I wrote, “In my experience.” So the citation is (AlwaysCurious, 2013).
If you have any citations to prove them incorrect and add to the discussion, I’d love to read them. I wouldn’t even be snotty if the citation was simply (Nick_Barkley, 2013).
There’s an echo in here. I thought that clearly stated alway’s original post. Thanks for coming in yet another thread and adding to the discussion.
We are all waiting on pins and needles to hear your scientific or unscientific opinion. In my experience (N=1), vertical oscillation has nothing to do with ankle lean or hip rotation. I am 6’4", nearly zero ankle flexibility, horrendous kick, yet I manage to run okay with very little vertical oscillation. High turnover is what got me from bouncing so much. Worked my way from 150ish to 180+ and lost the oscillation.
I know a few very tall guys (6’3"+) who run with a 130-150 cadence. They’re beginner to middle-of-pack runners, mostly because they say it hurts to run, so they don’t do it much. They’ve all experimented with quickening cadence, shortening strides, and decreasing time on the ground, with varying degrees of success.
It seems to be a common theme among very tall adult-onset runners. Can you elaborate on your transition to higher cadence, and anything else you’ve done to improve your running?
I’d be interested in seeing how these metrics change over an evenly paced (flatish) marathon distance.
It’s some interesting data. hard to tell how useful it is yet, but perhaps once there’s a body of data to work with, like most things, people will then be able to find correlations that match their previously held ideas.
I’m glad you started this discussion because I’ve had my eye on the 620. I got my girlfriend a 220 over the weekend (no running dynamics from the HR strap other than the stride rate/cadence) and I was very impressed.
The satellite acquisition time was amazing compared to my 910 (still acquiring satellites ~1.5mi into the run), and the thing is extremely light.
Just out of curiosity, do you know whether there are any features built in that attempt to “learn” your pace based on stride rate and/or vertical oscillation measurements from outdoors where it can correlate the run dynamics to GPS-based speed? My GF thinks the indoor pace stability has been improving slightly after a few runs.
I know a few very tall guys (6’3"+) who run with a 130-150 cadence. They’re beginner to middle-of-pack runners, mostly because they say it hurts to run, so they don’t do it much. They’ve all experimented with quickening cadence, shortening strides, and decreasing time on the ground, with varying degrees of success.
It seems to be a common theme among very tall adult-onset runners. Can you elaborate on your transition to higher cadence, and anything else you’ve done to improve your running?
Let me preface this by saying I am by no means a great runner and don’t want to give the impression that I am. I will probably never BQ, certainly will never KQ, and really don’t like open run races. I do OK on a local level for tri/xterra and getting chased (while chasing) on the run is something I am beginning to enjoy.
I ran quite a bit as a kid playing basketball, baseball, and football, but didn’t run much for roughly 15 years after high school. Was always one of the fastest kids, but think that had a lot more to do with athleticism than run economy. Had a run analysis done by a reputable coach after I committed to triathlon. He suggested I take up ultra running and I assumed that was a jab at my run form and that I would never be a fast runner :-). He gave me several drills to work on, but really emphasized increasing my cadence and trying to decrease the VO. On video I looked like I was jumping up and down. I transitioned using a metronome over several months and found it to be a fairly easy transition. The metronome made it easy for the cadence piece and allowed me to focus on VO. Of course with increasing my cadence that much, it shortened my stride (and it was already short) and also decreased my time on the ground. I no longer felt like a gorilla when I ran. That was five years ago and I still pull out the metronome every once in a while to make sure I am not slipping into old habits. Maybe it’s because I am taller and I look odd/goofy with that high of a high cadence, but once in a while I’ll actually get complemented on my run. Running a lot more helped as much, if not more than anything. Not BarryP volume, but 3-4x a week consistently. I have found that I have a hard time running more than two days in a row. Also, trail running has been great in so many ways; injury prevention, lack of boredom, forced hill work, building strong ankles, and increasing mental strength just to name a few.
I’m not familiar with the new metrics they are using - haven’t looked into the 620 yet - but I don’t completely agree with your take on vertical oscillation necessarily increasing with speed. If leg speed and power from the toe-off increases you will cover more ground - horizontal distance - without necessarily bouncing higher off the ground. Taking advantage of the elastic recoil of your legs is the right line of thinking but that isn’t necessarily the same as springs generating vertical displacement.
How are they estimating vertical oscillation anyway? I assume from the foot-pod cadence senson but that is estimating the displacement of the foot, not the runner’s body.
The problem with intentionally reducing vertical oscillation is that it has been shown to decrease running economy. When you run faster, your contact time decreases and vertical oscillation increases. This makes sense if you think of running as a series of controlled jumps and your legs as springs (spring mass model).
I would not recommend spending your valuable training time trying to chase these metrics.
As a certified pose coach im very interested in this watch. I dont think there will be a one bounce fits all, but from a pose session i will be able to figure out 1 persons time, and as an extra tool give them something to work with when they get home.
But this is all still theory, im looking at how it works out in practice.
If theres any other coaches out there fiddling with this, please give me a shout.
