When do you start the clock during intervals?
Regarding the higher intensity training, specifically Intensive Repetitions at level 5 - short 30-60 seconds, long 1-2 minutes. Full recovery in between. For the sake of argument let's say full recovery is to 110 bpm and level 5 is at 155 bpm (I'm 53 and my heart rate runs about 20 bpm below most of my compatriots while skiing or biking). How is the build-up included or not in these times, for example, particularly roller skiing, it will take me 1-2 minutes to get from 110 up to 155, let's say 90 seconds. Does my 60 second short interval take 2.5 minutes (90 sec to get up to 155 and then 60 seconds at 155) to complete, or do I just go really hard for 60 seconds? Running or bounding up steep hills have a steeper ramp for HR, but it will still be close to a minute to get up to 155. This one has been perplexing me for some time, so I'm hoping for some clarity.
Hi here's my take,
I wouldn't be too concerned about what your heart rate is getting to. The short answer is, L5 pace is more important to me than the immediate response to L5 work. One of the things which I think is often lost in translation about intervals is what they're supposed to accomplish. Heart-rate monitors are good tools, but I think that (to some degree) they've put the majority of the focus only on what your cardiovascular system is doing. Different training focuses will have overlap. When we design training plans for the CXC Team, we look at a few things -- and this is where our friend, the Venn diagram, comes into play. We often look at doing one primarily thing in training, but we always affect many others.
First, we look at the substrate you're using -- are you doing intervals (burning primarily carbohydrate) or easy distance (primarily fats)? We do testing -- VO2 specifically, but correlate these results to heart rates -- to see where individual athletes need improvement. If you are mostly burning glycogen stores when you're barely skiing, you're probably at risk of bonking in longer races when going fast. L3 intervals will burn a higher percentage of fatty acids than carbohydrate, in comparison to L4 or L5 training.
Next, we look at how much tolerance to acids you are focusing on -- how high you want your lactate levels get. My feeling is that a lot of exposure to high lactates is too stressful to sustain for very long, so we don't do a lot of this work in the summer. At CXC, the majority of time spent in intervals is at L3, especially in the summer. Training at higher lactate levels will result in faster, more complete buffering, but the time it takes for most athletes to develop these adaptations isn't very long, so we hold off on these until we approach race season.
The final piece of the puzzle is how much muscle you're recruiting. If you're doing easy, slow movements, you aren't recruiting as many motor units as you will when you're sprinting as hard as you can. The consensus is that, by improving the number of muscle fibers you can recruit at maximum effort, you will reduce the amount of neuromuscular activation needed to move at slower (and/or race) paces.
Back to your question: I look at L5 intervals being more about neuromuscular recruitment first, acid tolerance second and substrate usage third. Yes, you will get higher heart rates [eventually] while burning a lot of carbohydrate; and yes, you will develop higher lacate levels and [eventually] adapt some tolerance. To me, sprint training is meant to make your sprinting more neuromuscularly efficient and economical. So, I wouldn't worry too much about how long it takes other body systems to react to this work.
Hope that lends some clarity and hasn't just raised a lot more questions!
Jason Cork
Team CXC Coach
Thanks - so the short answer is - to make sure I understand it -
max intervals will be short and the time 'counted' for the interval will be the time from when I start the high intensity movement not from the time that I reach the actual work level as measured by HR.
So if I'm bounding up a 75 second hill and going as hard as I can (while maintaining technique of course), that is a 75 second interval and I don't call it a 45 second interval because it took the first 30 seconds to get my HR back over 145-150 and into the 'L5 zone' from the 100-110 it dropped to while coming back down from the prior interval - correct?
I'm following a training plan I've developed myself based very closely on Rob Sleamaker's SERIOUS methodology with some adaptations for skiing and our relatively short season here in Ohio. From the folks I've talked to and what I have read about the CXC training plans, it is pretty similar. My target is for 400 hrs, but I usually fall a bit short of that with work, family, etc.??
Yes,
that's concise way of saying it. 75 seconds on from when you start at L5 pace, not when you reach an "L5" heart-rate. At the very least, that's the way I've always approached intervals, and the way we do it now.
To complicate things: there is this thing called EPOC -- Excess Post-exercise Oxygen Consumption. That is a fancy way of saying that it takes longer to reach baseline when you push yourself harder. If you are recovering to 100-110 coming downhill after L5 intervals, I would assume that you would recover to 90-100 if you went uphill at L3. So be aware that if you do the same recovery time after L3 as you do L5, you'd be starting the L5 ones with an elevated heart/metabolic work rate.
Jason Cork
Team CXC Coach
