i want to improve my speed a little bit.
often i run 12 x 400 m in 85 sec with 40 sec jogging rest ( i am a 19:01 minute runner for 5 k)
is 6 x 400 m with 2 minutes standing rest a good workout?
I have heard I should increase the recovery but is 2 minutes good???or more???
and how fast should I aim for the 6 x 400 m (all out) or just maybe 80 seconds -78 seconds???