Tabatta Sprints
 

If I'm doing tabatta intervals for my sprints, how many times a week can I do this before I start to see too much cortisol release/accumulation? I only want to sprint enough for health/longevity and a little bit for performance, but not where I'm getting cortisol to the point of it being problematic because of so much sprinting. Thanks.

What exactly is the goal? IMO, sprints are not well-suited for Tabata-style training. You will get almost zero improvement in sprint performance from this method of training, if that. Not sure what the health and longevity effect you're looking for is. . .

You're better off doing traditional sprint intervals. Sprints don't lend themselves to Tabata because deceleration takes up at least half of your rest period.

I use to do 3-4 times a week, then on the 3rd week maintain the same days but cut the total distance down to 40%-45% of the furthest total distance I ran the previous week. Worked really good, the first week I was running around 600meters total distance per 3:50 tabata, by the end of the phase I was almost at 1200meters per 3:50 (in this case the rest week would be 100mx5, or 500m 3-4times a week). It gets to the point where you build so much speed on the runs the rests turn into jogs, and is more intense than crossfit fran.

Yep.

So even if I do normal sprint intervals how many times per week can I get away with it without having to worry about dosing myself with cortisol?

What would you recommend for a work/rest ratio? I've heard 15s work and 30s rest, or 30s work and 60-90s rest. And of course Tabatta as well but it seems that might not be the way to go.

What is the goal for doing the sprints to begin with?

Sprinting improvement?
Fat loss?
conditioning?

That will dictate your work/rest ratio.

This is what I was trying to get at earlier.

If the goal is sprinting improvement, you need to consider going very close to (if not all the way to) full recovery, which for most people is about 1 minute per 10m sprinted, so 4 minutes to recover from a 40.

If the goal is fat loss, I would still argue (if you have the time) that you should go the full recovery route as well, because you'll get the fat loss benefit and the sprint improvement benefit as well.

If the goal is conditioning, then either of the intervals you suggested should work OK, although it would depend on what you're trying to condition for. Different times/distances for rugby vs. trying to improve your kick at the end of a 10K.

This is the stated goal.

If that's all you want, go to a junior high or high school track.

One day you can sprint the curves and walk the straights for about 20 minutes.

On another day you can run a 400, rest 8 min., run another 400, rest another 8 minutes, and run another 400. Or just do a couple of them.

On a third day, you could sprint 20x50 or 10x100 or 5x200. Go all out or run build ups. Recover awhile between sprints.

It's not big deal. And, for the love of God, quit worrying about cortisol. It's like you've been reading some CFer's blog. Get a reasonable amount of good food, exercise, and rest, and everything will take care of itself.