Using tempo benefits capillarisation and aerobic fitness but the greatest improvements in these areas will be when working at VO2max. I am thinking 75% tempo at 300-500m distance hits atleast VO2max for a sprinter but does anybody know for sure?
Wouldn’t hitting your VO2 Max also depend on the length of the recovery.
Hitting VO2max for long enough will depend on recovery, but with tempo recovery is no problem since lactic acid is not produced in any great amounts. If VO2max is above tempo pace and hence more lactic is produced, recovery should just be lengthened to allow for the remaining reps to be run fully and properly.
A couple thoughts:
A primary benefit of working at VO2 Max is maximizing the stroke volume of the heart. At speeds faster than VO2 Max, the heart must be increased to the point that stroke volume can’t equal 100% simply because the process takes longer than the need for oxygen. The benefits of increased stroke volume probably contribute to improvements in aerobic fitness as much as capillarisation.
Isn’t capillarisation specific to the fibers being recruited?
VO2 Max is much slower than the tempo pace used in 100-200 meter reps…75% of 10 seconds is 3:20 mile pace…much faster than vVO2 Max pace. If the benefit of tempo is increasing capillarisation to raise the body temperature to lower resistance for increased motor unit activity, this probably isn’t a bad thing that tempo is carried out at speeds faster than VO2 Max or speeds that recruit predominately FT fiber.
The optimum way to improve VO2 max is to run 3 min efforts at 3000m pace with 3 min recoveries. There are some variations on this - but this is reasonably well accepted in distance running circles.
Its why distance running schedules so often include things like 5 X 800/1000.
A 3000m race represents the longest distance at which most people can sustain max VO2.
I come from a distance running background so hesitate to advise sprinters. But my guess is that intervals of this distance are too long for sprinters. Loss of form, inadequate use of faster twitch fibres. Maybe the approach is shorter intervals at this pace - retaining sprinting form - but with shorter recoveries will have the same VO2 effect.