Back in 1996, a team of Japanese researchers led by Izumi Tabata published a study comparing moderately intense training (60 minutes of cycling at 70% VO2 max) to intermittent high intensity training (7-8 sets of 20 seconds at 170% V02 max with only 10 sec recovery). Subjects trained 5 days per week for 6 weeks.
The results? The first group improved their V02 max from an average of 53 ml/kg to 58 ml/kg. Anaeobic capacity did not improve.
The high intensity interval group bettered their V02 by 7 ml/kg, and perhaps not surprisingly their anaerobic capacity increased by an astounding 28%! Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and VO2max.
According to What Are Tabata Sprints?, this single study "spawned a specific training method: the Tabata. Quite simple and effective, a Tabata session consists of twenty seconds of maximum output, followed by ten seconds of rest, repeated eight times without pause for a total of four minutes. Any exercise will work (running, cycling, burpees, jump rope, squats, etc.) Doing Tabata sprints is perhaps the most rewarding – and physically taxing – way to spend those four minutes.
I'm not sure Arthur Lydiard would approve, especially when you are in a base-building phase of training, however once you are fit this might be something you could add to boost your anaerobic fitness- perhaps on a bike.
Impressive results for just a 4 minute workout!