Friday, April 13

We have three teams competing this weekend at the Rookie Rumble at 8th Day Gym. The event starts at 9 am so come down to support the 616ers if you can!

Also, I started following this guy recently and he is putting out some great information in fairly-simple-to-read Instagram posts. I think some of you might be interested. Lots of good info here, but you do need to read carefully to make sure you're getting it right.

Here's a post he did on the accuracy of different heart rate monitors:

With the booming growth of wearable technology in sport and fitness it is important that consumers are informed of the performance and accruacy of these devices. A common feature of today's fitness trackers include a heart rate sensor. Many of the latest trackers as presented here use reflective PPG sensors at the dorsal wrist to detect and measure HR. This is the green light sensor that you often see with these trackers. Continuing off of my work published in 2016, Boureaux et al. recently published a study looking at the accuracy of 8 fitness trackers on heart rate measurement during resistance exercise. Resistive type exercise has shown, as in my study, to negatively affect the accuracy of PPG HR measurements so they put them to the test in 50 participants. Results showed that only 3 of 8 devices met validity criteria when tested against the gold standard research grade ECG device. These include the Polar H7, Polar A360, and Bose SoundSport Pulse. The Bose earphones (PPG sensors at the ear) and Polar H7 (electrocardiac chest strap sensor) had the lowest error score while the TomTom Touch had the highest. This is interesting considering past research suggesting that the worst place for PPG HR detection is at the dorsal wrist (most trackers) and the ear being a better spot. PPG has it's inherent limitations and industry tech folks are continuously developing proprietary controls for all the factors that limit PPG sensors like skin pigmentation, sweat, and compression. Interestingly the data also showed similarities to my study in that the HR accuracy drops with increasing exercise intensity except for the Polar H7 which uses an electrocardiac chest strap sensor instead of the PPG. If you are however looking for a wrist worn tracker, the Polar A360 seems to be the most valid of the PPG based watches. Look out for my guest article in the next issue of Monthly Applications in Strength Sport (MASS) fitness tech series.

A post shared by Eddie Jo, PhD, CSCS*D, CISSN (@dr.eddiejo) on

Workout for Friday, April 13
"Grace"
30 Clean and Jerks for Time (135/95)
*See 8/4/17

***Get Full Recovery - 7 to 10 min***

Back Squat
EMOM for 3 min
3 Reps @ 60%
- Rest 1 min -
EMOM for 3 min
2 Reps @ 70%
- Rest 1 min -
EMOM for 3 min
1 Rep @ 80%
- Rest 1 min -
EMOM for 3 min
1 Rep @ 85%

CrossFit 616