CNS impact of 250-300m

I’ve been considering this for a long time. Does anyone else believe that the CNS impact of running 2x250-300m is super low even at 100% effort. Of course this would be relative to the level of the sprinter. But say for a mid level sprinter with a terrible lactic system. Mainly because of the very low volume and intensity of the overall run.

I’ve been considering for a long time if doing a 4x/week program would have additional speed end/lactic benefits.

Do you think the impact of doing 1 speed, 1 SE, and 2 250-300m workouts per week would have the same CNS impact as 2 speed, 1 SE would? Maybe even less so.

I’m just curious as to what others feel the impact of higher lactic running has on the CNS and how this effects how you can organize a week.

This is almost like CF’s 400m program is laid out, but instead of the CNS impact of 600’s its 250-300m.

If you are talking about H.I. sessions 4/week, the first thing you would do was to change the cycle format to a 2-1 probably. The rest depend on what the athlete is ‘made of’ so to speak (e.g., CNS tolerance), among other factors, of course.

Ya 4 Hi sessions per week. But every Hi session is not created equally. I just get the sense that the lactic type 250’s and 300’s dont drain out the CNS nearly as close to 120-150m speed endurance does and thus can be incorporated more frequently without having too much additional CNS stress.

interesting question, but i’m not sure it would have the effects you wanted. I’m assuming you would be performing this to the block leading up to your outdoor schedule? In my head I organized the template to what I thought could possibly work:

Day 1: Speed
Day 2: 250-300m work
Day 3: off
Day 4: SE
Day 5:250-300m work
Day 6:Tempo


Day 1: Speed
Day 2: 250-300m work
Day 3: off
Day 4: SE
Day 5:tempo
Day 6:250-300m
Day 7: off


The overall concept of 250’s and 300’s being very low on the CNS stress scale is very interesting, especially for those with very low tolerance for short speed work. I’m really starting to think I’m one of those people.

I’m strongly leaning toward doing a mixed program outdoors (one day short speed, one day SE type runs starting at 350 or so), and it will be very interesting to see what the end results are.

I am a big time ectomorph (see Kelly Baggett’s “The Skinny Fat Ectomorph” articles and that’s pretty much me in a nutshell). Interestingly, I don’t mind doing the longer work at all, and I seem to tolerate it very well, which supports your personal experience as well.

So where does the CNS reside in the body and how can it be measured ? Perhaps someone can point me towards research proving its existence.

Heart rate (during and after training), lactate levels, VO2 values and muscle fibre condition are all specifically measurable and have a direct or strong indirect link to training effort and recovery status.

The problem with CNS is how do you measure it`s condition during/after training ?

I wonder if it is like dark matter in the universe - a possible explanation to a phenomenon but one that has never been measured !!

Or am i just being thick !!


I had similar thoughts

Day 1: Speed
Day 2: tempo
Day 3: 2x250
Day 4: Tempo
Day 5: short SE (80-150)
Day 6: 2x250
Day 7: off

But many programs follow
Speed, SE, off Speed, SE off template

Measuring the CNS stress is a whole different ball game.

The depth of CNS stress is so vast its very tough to measure. But going by feel and observation is probably the simplest method. And you can tell pretty quickly how your body is going to adapt to the work once you get going.

I’ve read Charlie say that there is a certain amount of highly CNS activities a person can do daily. The interesting part of designing these sprint workouts with the idea of a cumulative CNS stress is how much and when can you stimulate.

Any more thoughts on the CNS stress of 300’s?

Charlie seemed to think that 600’s were very low CNS stress and could be done after a high CNS day. Is it possible that the distance is much lower?

So, you are thinking of adding a SE session and you expect more or less the same CNS stress? And although important, is this the only factor you are concerned with? You can try it and let us know how the season goes! As I said, IF for some reason I had to try this, I would definitely go with a 2-1 format. We all live to learn though!

Better get massages once every two weeks and plenty self recovery. Your weights better be in maint!!!

I’m still on the fence about it. Last year i did the speed, long Se, Short SE setup and it worked very well. And outdoors is still sometime away from now.