Nearly every week during the year, regardless of my training block, I do a continuous tempo run of around 40 minutes.
Building up towards an hour as I become stronger and then also adding incline depending on the time of year.
WORKING AT “YOUR” CORRECT AEROBIC LEVEL
I think what I do is loosely called by most people their threshold run, but I specifically do it slightly easier, strictly keeping below a set heart rate. In the early days the heart rate ceiling worked out by a laboratory lactic level testing in the Olympic programs before I’d start a main block of training.
But this isn’t necessary for most (and now myself as well) the goal pace is simple to work out. Aim to make the 40 minutes running at best pace you can while staying even and in control. You will notice a slight heart rate drift (+5-10 beats) throughout the session which is normal but if you suddenly see a spike in heart rate or you start gasping for breath then it’s beyond the aerobic capacity.
Each week I stick by the same heart rate ceiling running with my Polar V800 watch and plan to improve on both speed and increase distance week by week as I become more efficient. It’s my way of teaching both my muscular and cardiovascular system to operated as aerobically efficient as possible, which is specific to what I need to achieve running at the back end of long triathlons or run long distances at speed when I won’t know the time I’ll be running for because of unknown terrain trail running.