Intervals

Laura L's training comment yesterday got me thinking about this and I'd like the guru's out there to confirm or correct...

I thought there were two types of interval session

1) Aim develop a finishing kick.
ie after a Long distance race you wnat to be able to change gears and leave a trail of rubber on the road as you catch folk over the last 400m.

For this you need to be able have a maximal capability to combine aerobic and anaerobic power even when the body has lots of lactic acid around but only for a short duration.

to acclimatise to this demand you do fairly short intervals (2-600m) with short recoveries and lung bursting pace.

2) Aim to develop the ability to run faster for prolonged distances ie cut your time off 5k/10k/half M.

You need to aid overall CV development and lactic acid tolerance over prolonged time and increasing level, but not extreme power as per 1)

Training is therefore geared to intervals at a bit faster than race pace (eg 110%)and over extended distances 800m+ with reasonable recoveries. the aim being to cycle through the lactose levels.

views?

sfh legs,

I've been pondering about this for 15 mins now, and it's puzzling me... (it's getting late, and I'm not sure I'm following you...)
I'm only dabbling with concepts I hardly understand here, yet it seems to me what you say is true, but perhaps for the wrong reasons...
The shorter intervals you describe here would indeed improve your finishing kick, but perhaps only because, at these sorts of speeds, you're exercising a large proportion of fast twitch muscle fiber.

However, as a distance runner I still do this type of interval session, but for different purposes... I think, essentially, that the 2 different types of interval sessions you talk about exercise the same metabolic pathway (glycolysis), the main aim being to stress the buffering system of muscles, and to adapt them for continued performance at low pH levels. Recoveries seem short, only because muscle pH levels have not fallen dramatically.
Now, the interest of that type of intervals lies in that, as I have mentionned, they mobilise fast twitch fiber, which does play an important role not solely in sprints, but also in sustained efforts of say 5/10K/half-marathon (proportions of FT/ST muscle fiber for a 10K/Half-marathon runner would be somewhere around 50/50).

Help, I think we need a physiologist here...