How to recover cardio vascular fitness

singletrackworld.com/forum/topic/how-to-recover-cardiovascular-fitness-in-2-weeks

High Intensity Interval Training

http://training4endurance.co.uk/improve-endurance/high-intensity-interval-training/

Examples of Supra-maximal HIIT sessions:

8-12 x 30-secs @ 175%PPO, with 4-5mins active recoveries (e.g. 30-50% PPO).

8-12 x 200m sprint, with 4-5min slow jog recovery

8-10 x 45-seconds @ 125%PPO, with 2.5mins active recoveries (e.g. 30-50% PPO).

8-10 x 300m @ 800m pace, with 2.5-3min slow jog recovery

2 x (10x40secs @ 110%VO₂max, with 20 second recoveries), 5 min between sets of 10

Examples of VO₂max HIIT sessions include:

5-8 x 3-4mins @ a pace/intensity that you could sustain for around 6-8mins in an all-out effort with 3-minute recoveries – recoveries should be at 50% vVO₂max (Running) or 30-40% of Pmax (cycling)

10-12 x 60-seconds @ a pace/intensity that you could sustain for around 6-8mins in an all-out effort with 60-second recoveries as above

15-20 x 30-seconds @ a pace/intensity that you could sustain for around 6-8mins in an all-out effort with 30-second recoveries as above

See also:

http://training4endurance.co.uk/running/running-intervals/