The art of intervals?
I've been reading articles about interval training for years, have done plenty of intervals, but I think there are still a lot of things left unexplained about how to actually approach them and what a specific interval accomplishes. This has, likewise, left me with some questions that come about as I do my sessions.
1. The intent is to "ride as hard as you bloody can", but can you actually do intervals too hard? I've found that if I push beyond the red zone, especially on the first interval when I'm most fresh, I'm unable to recover well enough to finish the rest of the session strong (or even at all). Is the goal in actuality to ride hard but also modulate your effort so you can finish the session, even if you feel like you had more left in the first few intervals? Your goal, really, is to ride beyond FTP, so a whole session at even 101% is going to be more more valuable than cranking one out at 125% and then burning yourself down to below FTP by the end, correct?
2. Is the longer the interval duration, the longer you train your body to ride at that effort? Obviously, the longer the effort, the less power you can produce since you have to sustain it, so is riding a 20 minute interval where you're close to FTP going to produce the same gains as a 3 minute interval where you're well in excess of FTP?
3. Do short, more or less VO2max intervals (30s-1min) improve overall speed, or only your ability to produce short, extremely powerful surges? Likewise, does doing short hill repeats at all-out effort really only produce short-burst power/speed?
4. One of the key points of intervals is to limit the rest period between each effort. Is there benefit to decreasing the rest time, even if it inhibits your ability to produce the necessary power on each subsequent effort? Or is it better to give yourself the time needed to recover for the next one to give 100% the entire session?
5. If your goal is simply to get stronger and faster in general, are the longer intervals more valuable than the short 1-2 minute intervals? Or is a combination of a short and a long interval day each week a better overall compliment? Is an 8-10 minute long (say 3x8) session a mix of both worlds, or is that not a suitable replacement for, say, a 2x20 day and a 15x2 day? Is there not really a one silver bullet that produces the best all-around results?