Comment...

Brett asks: Hi Tim, please see This Post and specifically #3 way down below...I have been meaning to ask you when it comes to speed work/intervals a few questions, and this blog post reminded me to ask again.

a) Is it better to do certain time increments (ie run whatever pace you can at a certain heart rate for exactly 30 seconds)?

b) Is it better to do certain pace increments (ie heart rate be damned just do 1 minute 400s)?

c) Is it better to do heart rate specific intervals (who cares what the pace is, just do 95% of HR for 30 seconds over and over)?

Specifically he makes this comment "the intervals should only be continued until the HR fails to drop to 120bpm within a given recovery period (30-90s dependent on the length of the interval) while target pace is held constant." which I guess is yet a part (d) option.

Or do you pick and choose amongst these choices for different reasons?

I apologize for putting like 7 questions into 1 post...feel free to not publish this comment or use it as part of another day's post if you want. I'll need 3 more days to decipher his physiology discussion anyway!

Wow... I haven't really thought of running for quite a while. I wish you had asked me how to hang a door in to a hurky wall..

I'm no physiologist, just a student of training. I've read all the books and trained with some of the best runners and triathletes in the world. I've run massive weeks and seen some success with several 2:30 marathons and placing 13th and 16th at Ironman Hawaii.. here's my opinion.

Q: Is it better to do certain time increments (ie run whatever pace you can at a certain heart rate for exactly 30 seconds)?

A: Your HR will not respond in just 30". HR can lag effort by ~1:00 or more. If the interval is less than a minute then do it on a track at a calculated pace that is specific to your weakness and goal.

Q: Is it better to do certain pace increments (ie heart rate be damned just do 1 minute 400s)?

A: 1:00 400's? If you can do that then there's no need to continue wondering about training! You're fit as hell! :) I would certainly say HR be damned on a 400 interval. Any time you use an interval that short then you need to be anaerobic. Otherwise you should be doing longer intervals..

Q: Is it better to do heart rate specific intervals (who cares what the pace is, just do 95% of HR for 30 seconds over and over)?

A: Once again, 30" is not an appropriate interval length for HR use.. And I would say to avoid using % of max HR (I am assuming that is what you mean by 95% of HR?) rather you should attempt to extrapolate your LT HR and use that as your guide.

Q: And finally: Specifically he makes this comment "the intervals should only be continued until the HR fails to drop to 120bpm within a given recovery period (30-90s dependent on the length of the interval) while target pace is held constant." which I guess is yet a part (d) option.

A: Using recovery HR is effective but there are parameters that are not specified. If you are standing still then your HR will fall quickly, if you are using active recovery then it may not. They both have benefits.
Using 120 bpm may be a mistake, it's too generic, like MAF. It may coincidentally apply to you. If my LT is 180 then 120 is too low and I would use a higher recovery HR. If an athlete's LT is just 160 then 120 is too high for a recovery HR.
I've been sick fit, tapered and peaked and have done intervals where I would stand still for 1:00 and my HR would not go below 120. So I should have stopped after the first interval? No!
I don't believe enough in HR being able to guide an athlete specifically or accurately. If you're dehydrated at all then your HR is going to be up to 10 beats too high. Mild dehydration, although it is a very bad thing, is not a reason to bag a track workout.

I think it is important too to distinguish an athletes specific physiological needs and fitness level. Using a generic number is a mistake. We are all unique and at different fitness levels, why use someone else's number?

And finally- allowing a HR monitor to control your training only teaches you incorrect limits. Over the past 6 months- thanks almost entirely to Uli- I have come to the realization that a HR monitor limits you, particularly as a pure runner. I think that the reason I have only run a 2:30 marathon is that I had too much faith in HR training. I do think an Ironman athlete can use HR effectively, but for the marathon and below it is not about HR. It's about mental strength and pacing (both in races and in specific training periods. IE: training your body to run XX pace at mile 20 of the marathon which I believe is more muscular than cardiovascular). I have HR data from 4 marathons, all of them within a minute of 2:30, and all the data is completely different. There's very little useful information! I will be using a HR monitor in my base building but only to hold me back. Once it comes time work, then I'm going to work! There are many different ways to reach your potential and I think the key to success lies not in the hard days, but in the easy days. It's critical to rest and recover, not so much within a specific workout, but in a weekly schedule. Easy days need to be easy and I believe this is maybe the key element to success. What you do on your hard days needn't be over thought. Leave that for the lab rats..