Alternative methods to classical FT intervals

Dini77

Something i've been meaning to ask for a while. What is the shortest interval time(s) you can use whilst still achieving exactly the same physiological adaptations (and benefits) as a classical 2x20min format? or what are some other alternatives that have delivered demonstrated and equivalent (ie quantifiable) results?

For eg, say you did 2 L4 intervals - 1x15min and 1x25min giving total of 40min @ L4. Is 2x20min L4 interval physiologically equivalent to this (ie inducing the same adaptation and benefits). What about 4x10min @ L4, 8x5min, etc?

In the case of FT adaptation, is it a function of the total riding time at level, duration of each interval @ level or both?

I guess i had more than 1 question .If this has already been covered somewhere, can you point me to it please.
Cheers

RapDaddyo

You probably need to clarify this part of your question, because 20 sets of 1min on/5min off at L4 intensity could be construed to mean 20mins at L4, which is clearly not the same as 1x20 or 2x10, both of which are in excess of the minimum duration for an L4 whereas clearly 1min is not.

Dini77

That's probably more to the point i was trying to get at - what is the minimum duration for an L4 workout?

If it's say 5min, will doing 8x5min L4's result in exactly the same physiological gains as 2x20min. Does it then just become a straight relationship of total time at L4, provided that your shortest interval is at the minimum duration for an L4 workout?

Has there been any studies looking at this that anyone's aware of?

WarrenG

When you get to where you're doing many reps at say, 4-7' each then there are things happening in the first minute or two of each rep that may or may not be what you're interested in doing.

I personally prefer intervals of less than 15' so I get those little breaks to just relax for a few minutes, have a drink, then get ready to go again. I do a lot of them that are 6-8', 4-5 times a week, and I do want to train the things happening during the ramp up of each rep.

Some people might want to do a more continuous effort because they're preparing for long TT's.

RapDaddyo

I follow Andy Coggan's schema, in which L4 is 10-30 mins in duration. But, it's not a hard line of demarcation. It's more like shades of gray. And, as you move up the power curve (and down the duration curve) to L5, it's not as though LT adaptation falls off the table and VO2MAX adaptation suddenly kicks in. There's substantial LT adaptation throughout the range from L4 and up. In fact, if you look at the studies of very short duration intervals (e.g., 30sec), the main beneficiaries are LT and VO2MAX as well. I don't know that the adaptation is identical between, say, 4x10 L4s vs. 2x20 L4s, but I think it's very close. I think it's more important to do them than it is which specific combination you do. It is that view of this subject that has driven me to my approach to intervals, which is course-driven and not traditional formulistic. I just get bored doing 2x20s or some-such track-like protocol. Doing a 3-4 hr ride with a whole range of L4-L6 intervals, at a whole range of durations within each range, with a bunch of variable power segments with a strategic pacing strategy keeps me interested mentally.

yawg

The short duration intervals need short rest periods. If your doing 8x5's keep the rest period to a minute or less to get the same benefits of the longer intervals. Jack Daniels the running coach calls these "cruise intervals".

greg

Dini77

This is precisely the reason why i wanted to clarify this. Since my brand new PT SL has just arrived , it should make these intervals a lot easier to manage regardless of terrain/condition - whereas, to date i have used velodromes/trainers a lot for this stuff and as you say, i'm mentally drained from this approach.

BlueJersey

Think about it in terms of the racing perspective. Would you be glad knowing that you can launch a flyer some 5 miles till the finish (roughly 15 minutes at L4 or lower L5 effort) because you have been trained to ride that duration?

acoggan

My recommendation to people is that they keep the efforts at 15 min or longer unless they're using very short rest periods between them. If the latter, it is possible to achieve the same whole-body physiological responses even using work and rest periods that are very, very short, e.g., 15 s on/off. (I specifically say "responses" and not "adaptations" because to my knowledge no one has examined the adaptations that results from training using such microintervals).

acoggan

Note that those are the typical length of intervals/efforts/"blocks" that people do to try to raise their LT. There are other ways of achieving the same goal, just as it is possible to design VO2max interval workouts that don't rely on 3-8 min long efforts.

RapDaddyo

Thanks. I'll make that point the next time I quote your schema. In reality, as you know, I just use 90%MP all the way up the power/duration curve, so the adaptation is really duration-dependent. BTW, the power levels also happen to fall within your ranges. I'm just at the upper end of the range at the lower end of the duration range and vice versa at the other end.

Dini77

I understand your point and yes, we'd all like to be certain we can punch it for the required time when required. But, I'm coming at it from an equivalency with respect to physiological adaptations perspective, not a phsycological perspective.
ie is 4x10min (assuming 10min is the minimum duration for L4 intervals) physiologically equivalent to 2x20min L4

BlueJersey

I think Andy meant that you need the necessary duration to cause adaptation. Notice that he mentioned "keeping the recovery time to the shortest." In a way, I am even sure if the short recovery duration would have any significant impact on your recovery rate. I could be wrong.