Saturday, October 11, 2008

The heart rate monitor: working for time and a fitness persective

Ok.  The first object is to consider what happens when we increase intensity and what we are training for.  

I typically burn 100-140 calories with a heart rate monitor but the benefits of fitness in a set( for time) from a physics perspective might be more.  There are two points that come to mind.  

1.  The work done by each rep and multiplied by the number of reps(Kinetic Work)  
2.  The rest of the time in between the reps(potential work)

While the heart rate monitor might be off it bases its calculation on heart rate.  What is interesting is what happens after the set is finished.

This had been done a few times.  I'll use this.  

I had a 5k run in 22.5 minutes
Average Heart Rate 165
Peak 180

I had one 102 reps for 10 minutes with OALC without setting the weight down and switching every minute.  1 32kg bell.  Average HR 175.  Peak 185.

Comparison

With Scenario 1: Burned 390 calories in 22.5 minutes and 160 in 30 minutes following
With Scenario 2: Burned 280 calories in 10 minutes and 250 in 30 minutes following

In this case the HR monitor doesn't know the activities themselves are different.  IT calculates intensity based on an exponential curve of HR approaching higher beats per minute.   Even though the kettlebell workout had been only slightly higher with intensity it made a bigger difference during and especially after the set.  Metabolism becomes increased and stays increased for longer.    Based on a workout, It had been 1200 calories-1600 in the first 90 minutes and who knows as it dropped off during the rest of the day and following day.   The thing I notice is that reps per minute do make a difference.  Weight does not necessarily have an effect in that reps per minute with lighter weights being inversely proportionate make p the difference with a lighter poundage.   The difference might matter more after the activity stops such as a higher HR for longer.  Gotta keep searching.  ;)  Get to work and use the HR monitor to see what is happening.  

5 comments:

Frankie Mecono RKC said...

Great report! I have been wanting to do this with v02max Kb work and treadmill. I just hate running on a treadmill.

Catherine Imes said...

I'm finding that nothing jacks my heartrate up like double work with the 20s even at a lower RPM. My HR topped out at 190. Just holding those bells for up to 8 min is brutal. I can get it to the 180 mark on snatches, but I think I adapted to the lighter snatches after doing them for so long. Heavier work (even slower) is much more intense for me.

It's interesting. It will be cool to compare notes.

maybe I'll see you in Cincy at the November Cert.

CI

Kettlebelllifter said...

Hey Frankie,

Thats good to compare your set of 6 minutes to a treadmill. It is interesting what happens when the set is over.

Kettlebelllifter said...

Hey Cate,

Its weird. Since The jerks I can find rest, it messes with me in that my HR jumps up sky high but I can't survive with 10 minutes of snatches with 32kg. I only survived 9 minutes publically:]

When I left the gym I had done on 7 minute set and 2 5 minute sets and JS. I stood around and talked to a few people milling about. When I left the gym I was at about 1200 calories. I burned another 600 when I got home doing a run and one armed Jerks. In about a three hour time frame (during and post workout) I burn 2000 calories. It adds up after a while. The good news is that people can get their heart rate high with all kinds of weights. I suspect with heavier weight for high reps, one can't dismiss the amount of work that goes into it.

Kettlebelllifter said...

Oh and yes I plan to be at the Cincy cert.