Precor 576i

Today I did 35 minutes of weight workouts (arms, chest, back and calves), and then hopped on a Precor 576i elliptical.  This is the elliptical that has the moving arms, stationary heart rate sensors for your hands, and a vertical ramp and moves up and down during certain workouts.  I selected the weight loss workout, which is 28 minutes long and it moves between two heights throughout the workout and has default resistance settings.  I left the height setting alone throughout the workout.  I did, however, change the resistance myself to keep me around a 150 average.  Unfortunately, this machine did not read my chest strap, and so I looked at my watch and changed the resistance accordingly. As you'll see, I did a pretty good job keeping myself at the 150 average.  This resulted in me using a resistance of 12 for most of the workout.  Finally, throughout the workout, I tested the hand heart rate monitors vs. my chest strap/watch monitor and at no point was there ever more than a 1-3 bpm difference.  The hand rate monitors are pretty accurate on the 576i.  Since I wanted to have my arms moving I went with my chest strap for a constant heart rate throughout the workout.

Avg HR = 152 bpm
Peak HR = 166 bpm
K Burned (watch) = 449
K burned (576i) = 315

Of course this machine did not have a constant heart rate, but the difference is consistent with my watch being way too aggressive in calories burned.  I am not sure if the chest strap is incompatible with all 576i's or if this one just wasn't working or had a dead battery for its sensor.  It's odd it would work with the 100i but not the 576i.  If I get a chance I will try another.