I'm wondering if the adage "speed kills" has been taken too far among many distance runners. Or at least the ones I tend to hang out with. I've been nurtured in my running by people that are generally self-described "Lydiardites" and I think they have helped me get a lot out of my talentless body. But, I am questioning some things.
I know that short, quick strides (like 60m) are OK because you don't go deep into gasping oxygen debt, but I hear that too much intense "anaerobic" running can burn you out and even destroy your aerobic enzymes. Well, how much is too much? Doesn't it depend on the kind and length of "intense" running? Doesn't it depend on the recovery between "intense" sessions?
I met a 400 meter runner who said he trained practically every day doing "intense" but not too many intervals on the track. Things like 6x200 one day, 3 x 500 another day, 4 x 400 etc. He said these workouts were tough during them but he never got "burned out". In my limited experience, it's doing longer things like 4x1600m at VO2 max which burns me out a lot. Or if I run my long run too fast, it takes a lot out of me.
I know some about soccer players training and what they do during a game. They are getting into oxygen debt all the time, every day--but with at least some time during a workout or game to slow down and recover. Yet, these guys bodies aren't getting run down by this constant natural "interval work". In fact, when I'm running a lot of miles it's me who needs all the sleep, who can get sick if I'm not careful while these guys are out partying.
The reason I'm asking is this: I'm sitting here with a knee injury that is keeping me from doing lots of miles per week. Interestingly, I can still do some relatively fast stuff no problem. I'm considering a drastic change in my training while I am recovering. I'm considering doing an experiment on myself. Doing stuff like 5 x 300 or 3 x600 almost every day. Sure it won't make me run a fast 10k by itself, but it may keep me in at least better shape than not. Also, I am curious to see how fast I could run 400m. But, my main concern is if I could harm myself in anyway by doing this. I don't like the idea of damaging my mitochondria.