I recently worked out at a gym on one of those fancy schmancy treadmills that take your heart rate and all. I used the fat burning work out selection at first, as opposed to the cardio workout. So the machine tells me my target heart rate is 114, which is about right for age and all that. And away I go. I walked to warm up and then ran at about 4.5-5 mph. Which is real comfortable, but definitely gets my heart rate higher than 114. In fact, more like close to maximum after a bit of time. Although I am always able to breath in a controlled manner, not huffing out of breath...just working hard. So my question becomes, am I short circuiting the fat burning by working TOO HARD and getting my heart rate higher or is it going to do the same and be a cardio work out too...I worked for 20 minutes, then did some strength training, then did 25 more minutes in the machine. Then today I did 40 minutes outside in the sunshine at a heart rate about 125 for probably half of that. Whaddaya think?

Jo