3 main running exercises?

saw most people say that to improve ur running / sprinting / jogging allat u just need

1. A long length run 3x a week( 40 min)

2. interval ( 10 sec sprint 20 sec jog x10)(2x a week)

3. full on sprint x 4 50 metres 2x a week

but like isnt this like packed ash? cuz I swear u need recovery for ur legs too. need help with this cuz jm trying to get 1.6 km for around 8 minutes( rn its 10 )