I started using the Garmin Forerunner 620 in November 2013, and did a brief review around that time. I’ve been meaning to talk about it again now that I am more familiar with it, but never got around to it. Today I thought I would discuss three of the features of the Garmin 620 that stand out to me: VO2 max, vertical oscillation, and recovery advisor. All of these features require the use of the HRM-Run strap. If you wear if consistently while you run, it can provide some interesting data that may help your training!
VO2 Max is a measure of the amount of oxygen that your body can use while exercising. While a higher VO2 max is generally better, it seems to be a rather individual measure. Therefore, if two runners have the same VO2 max it doesn’t necessarily mean they will run the same race times. When thinking about your own VO2 max, as your body is better able to use oxygen, you will be able to run faster at the same effort. That is why it is important to do workouts that improve VO2 max and train in a way that will allow your running to become more efficient.
When the Garmin HRM-Run strap is worn consistently, the data provided from your heart rate is used to calculate an approximate VO2 max. I have noticed that mine will go up and down slightly from day to day or week to week, but when I am training consistently I notice an overall increase in that number. My highest ever VO2 max was last fall when I was training for the Philadelphia Marathon.
As you can see from the chart above, I stopped wearing my HRM after the race so there is no data, and once I started running again in the spring it took some time to build up my VO2 max again. Ever few weeks I will get a notification that my number has gone up, and that is always a good feeling!
Vertical oscillation is the amount of bounce, or up and down motion, that happens while running. Less vertical oscillation is better, because this means you are running more efficiently. The Garmin HRM-Run tracks this by measuring how much the actual heart rate monitor moves up and down while you run. It is measured in centimeters, and I have found that my vertical oscillation is generally around 10-11 cm. When its closer to 10, the graph has more “green” in it versus orange, so that means I am closer to an ideal amount of movement.
Lately I have noticed that as I am working on my strength and stability, I am seeing lower numbers in this area. Changes of less than a centimeter might not seem like much, but the more we are moving up and down the more energy we are wasting that could be reserved and put into our forward running motion. The following graph is from earlier this spring:
I definitely notice that my vertical oscillation is higher on days when I am tired, or at the end of a tough run. Surprisingly, it looks the best when I run up hills! I think that may be because hill running encourages good form.
The recovery advisor includes recovery time and recovery check. At the end of a run, the Garmin 620 will display a recommend amount of recovery time based on my heart rate. So after a short, easy run, it may say 12-18 hours. After a long or more challenging workout it may be a few days. Recovery check is a way to gauge recovery status a few minutes into a new run. Usually about 5-10 minutes after beginning my run, the 620 will display if my recovery is “good” or “fair”. (I haven’t seen any other ratings besides those two.)
This feature was helpful when I did a 10 miler on a Thursday and had a 5k the following Sunday. The 10 miler was harder than expected due to heat and hills, and it really wore me out. After the run my recovery time was 3 days. This would give me just enough time to recover before the 5k, but I was still nervous that I wouldn’t be fully recovered. When I ran my warm up on Sunday morning, my recovery status was displayed as “good”, which eased any concerns I had about racing that day.
In this case there was nothing I could really do because that was the day my race was scheduled for, but in training this feature could help with scheduling workouts. If I did a tough workout on Tuesday and needed 3 days to recover, I would wait to do another hard workout or long run until at least Saturday.
These features are not by any means a necessity for a running watch. They are definitely “extras” that may help with measuring your progress if used consistently. I like the data, so I find all the graphs and charts and numbers helpful. It did take some time to start using these features in the way they are intended, and to see some patterns emerge. I actually don’t think much at all about pace (unless doing a specific workout), but instead focus on training properly and improving my running efficiency, all of which can be monitored using these features.
I hope that you found this at least a bit interesting or helpful! Let me know if you have any questions about anything I explained, or the watch in general!
What kind of running watch do you use?
Do you track any data from your runs besides distance and pace?