Ground contact time, stride length, vertical oscillation, and stride rate amongst various shoes

I wanted see how various minimalist shoes affect my ground contact time, stride length, vertical oscillation and stride rate.

To do this I used my Garmin 920XT paired with the newest Garmin HRM. You can see the raw data here.

Continue reading “Ground contact time, stride length, vertical oscillation, and stride rate amongst various shoes”

Garmin 920XT vs 620 vs 220

Garmin 920XT is a huge improvement over the Garmin 620

A few key features:

  • Daily activity tracking
  • Sleep tracking (with built in accelerometer)
  • Smart watch features (see emails, text and other notifications)
  • Indoor run tracking through accelerometer
  • VO2 max estimates
  • Race predictor based on last runs HR and pace
  • Large easy to read screen
  • Vertical Oscillation tracking (with HR monitor)
  • Ground contact time tracking (with HRM)

Garmin Forerunner 620 Review: Is it worth $450

The Garmin 620 has some pretty impressive features, but it cost $450, that’s $200 more than it’s little brother, the Garmin 220. Is it really worth the extra $200? Check out the above video for some of the useful features.

Here are a few of the notable features that differentiate the Garmin 620 from the Garmin 220
  • VO2 Max estimator
    • This is a really cool feature that estimates your VO2 max. It can even estimate this when running at sub VO2 max speeds. You don’t actually have to run all out. If you know your max HR, the watch uses math to estimate based on your speed and %HR
  • Race predictor
    • It can predict your current race fitness without making you run a time trial!
      • It takes your HR and speed of any given run and uses fancy mathematics to give you a prediction of your current race fitness, amazing! 
      • My race predictions were fairly accurate
  • Recovery Adviser
    • Based on things like heart rate variability, it gives you an estimate of how long it will take you to recover from any given workout. I ran a 10k time trial yesterday and it told me it would take 72 hrs to recover. I then went for a run today and it gave me an update on how well I was doing on my recovery; it told me I still need about 40 hrs to recovery from the effort
  • Run Dynamics
    • Uses and accelerometer in the HR monitor to tell you info about vertical oscillation, ground contact time, and gives you a real time score during your run to help you adjust your stride
  • WiFi: the watch has built in WiFi, so it can upload as soon as you step inside
  • Internal watch accelerometer: keeps track of your distance while on the treadmill. The watch will become more accurate after it calibrates automatically from the GPS data of an outdoor run (220 has this as well)
garmin 620 vs 220
garmin 620 vs 220
There are a lot of similarities between 220 and 620
garmin 620 cradle
620 uses magnets to hold watch in cradle
gamin 200 vs 620
620 is only slightly thicker and a little heavier
new garmin hr monitor
I found the new Garmin HR monitor to not have erratic HR data as the old ones did, it now has 3 sensors on the the strap plus a built in accelerometer to measure run dynamics such as vertical oscillation, and ground contact time
Both cradles can charge and upload data. The 620 uses magnets to hold watch in cradle, 220 use a snapping lock-down

ithlete Finger Sensor Heart Rate Variability Review

I’ve been using the ithlete heart rate variability app to monitor my HRV. The theory behind it is that the higher your HRV, the more rested and recovered you are. This can help you monitor when you should do a hard training session and when to back off. So far I’ve found it to be somewhat useful and have actually made adjustments to my training based off the feedback from the app. The app gives you 3 key colors to monitor your training:

  • Green: you’re recovered, ideal conditions to do a difficult workout
  • Amber: take an easy day or do something moderate
  • Red: take a day off or easy

I’ve found the ithlete finger sensor to give more consistent results when taking my HRV as compared to a bluetooth heart rate monitor. I also find it easier than having to put on a HRM and moisten the contacts.

ithlete finger sensor

ithlete finger sensor

4iiii Viiiiva Dual Heart Rate Monitor w/ iPhone Connectivity Review

The Viiiiva 4iiii HR monitor is a really cool concept. It connects via Bluetooth with your iPhone to send HR data from the strap itself, but also collects data via ant+ and sends data to iPhone from your Garmin footpod, cadence sensor, or Garmin power meter as well. I was hoping that for $80 it would overcome the limitations of the Garmin HR monitors, where they don’t work great until you start sweating, but alas, it has those same limitations. I mainly used this with my heart rate variability app called ithlete and occasionally with my Garmin 310xt when running. I have since started using the ithlete app with the ithlete finger sensor; it gives better, more consistent results.