Aerobic threshold

Running at a fixed heart rate is not as good as running by feel. You are imposing a training regime by sticking to a pace or heart rate, but some days you should run faster and some days a lot slower to get the best trained effect.

Davidfoster wrote:

So i have my aerobic threshold tested at 165bpm (85% mhr). What would happen if i would run at this heartrate everyday for like 5 miles ? No intervalwork. Only 5 miles at aerobic threshold.

That's Tinman Tempo pace, or ~marathon pace. Running at this pace every day would make you good at running this pace every day and make you very fit generally/efficient at fat burning, but wouldn't optimize any of your race times.

For 10k and less - too slow, you don't have the same running mechanics like frequency, knee lift, force into ground, etc.

For half and full marathon - too short. You need to prepare your body for 26 miles of pounding on the roads, the pace would be useful since it's ~marathon pace and HR, but you would need to do much larger volume.

Why is this pace good for burning fat? In percentage, you burn less % of fat than if you run slower, say at 140 HR. But you burn more calories overall, so also more fat in absolute terms. So the pace is quite good, but needs to be integrated with faster, and slower paces in a good training program.

Thnx guys!