It is getting harder to push my heartrate up above 140 which is good news, but it makes workouts more difficult. I did a 6.23 mile MTB ride yesterday and you can see the heart rate was varied, and a lot of times dropped down low.

Date: Jul 3, 2012 8:10 pm
Distance: 6.23 miles
Elapsed Time: 45:23.9
Avg Speed: 8.2 mph
Max Speed: 16.1 mph
Avg Pace: 7' 17" per mile
Min Altitude: 790 ft
Max Altitude: 876 ft

polar heart rate monitor chart

If you take a look at the chart below here, you see the workout from this morning where I crosstrained with the treadmill and free weights. The average heart rate is higher, and I did a burst at the end to bring the average up. Working out on a stationary piece of equipment makes it much easier to control your heart rate, but the downside to the treadmill is it is really hard on my knees.

polar heart rate monitor chart