CoachB wrote:
OK. So there is consensus that you're getting VO2 adaptation and efficiency at race pace.
I tend to agree with SoCal Pete that the rest ought to be kept short to keep the heart rate up in the 90% range for as much time as possible. I am, however interested in Prince of the Kenyan Highlands elaborating on why a longer rest would be preferable?
I can see if you were at altitude that longer rest might be needed.
OK, here comes the explanation. And its surprisingly scientific knowledge so far back as the -30s
and the great German coach Woldemar Gerschler and Ph Dr Reindel !
http://www.newintervaltraining.com/old-interval-training.php"The training principle was based on the fact that the volume of blood is constant for a given individual. As the heartbeats diminish in the interval for the same volume of blood, the quantity of blood pumped at each beat is increased in volume- the training effect comes then as the heartrate
decreases. " and " If this reduction of the heart rate to 120 bpm did not occur within 90 seconds
of the end of the previous faster run, the workout was considered too difficult and had to be adjusted. Otherwise, the heart would be overworked, leading to fatigue and exhaustion,rather than
to the desired training effect."
The last sentence there about an overworked heart and fatigue /exhaustion is also what happens if
the recovery interval is too short and the heart dont get the recovery it needs for optimal training effect. We can resemble this by a high-speed engine which becomes overheated.
http://www.racingpast.ca/john_contents.php?id=129Also we can here read " It is the recovery,not the effort,that develops the heart, or enables a stimulus particularly powerful to reach the heart."