I am Plata and first of all: sorry if my english is not so good, but I will give my best.
In my last workouts I did some experimenting with weights, sets and reps. What was really interesting for me was this:
when I do for example squats, I usually do it with about 300 lbs. for lets say 5 sets of 6-12 reps.
Now if I change my workout and do all 5 sets with 150 lbs. it is of course easier than the 300 lbs. but it still feels somewhat heavy.
But then in the next workout I did something completely different:
I started to work up slowly to warm up (10 reps with 90 lbs., 5 reps with 150 lbs., 5 reps with 200 lbs.) and when I continued with low-rep heavy sets:
3 reps 250, 2 reps 300, 1 rep 350, 1 rep 350, 1 rep 350
After this heavy singles I put down many plates and go back to 150 lbs.
And here comes the funny thing: the weight now feels so light, it seems almost there is no weight at all. I feel very powerful, like maybe someone would feel on steroids (I am not sure, I never tried them) and now I can do maybe 50% more reps than I usually do with this light weight.
I know that what I did and felt is nothing really new and does not seem to exceptional. Many of you maybe think "of course, if you use very heavy weight at the beginning the lighter weight in the later sets will feel even more light".
But the thing is it does not only feel light, it is lighter now for the body, I can do more (much more) reps than I could usually do with this weight.
What I would like to know is: what is going on in the muscles and the nervous system ? Can someone give me a somewhat scientifically solid explanation for this phenomenon ? Is it because the heavy weight activates more fibers (which then are still active in the later lightweight sets) or is it a higher coding rate or both ..... what is exactly going on in the muscles ?
By the way, I tried this with other exercises (like benchpress, barbell curls, military press and it is the same, but it seems to me the more weight I can use in an exercise the better it works, so maybe concentration curls are not the best choice for this ...).
Thx to everybody who can help me on this one with some good explanation !
Thread: muscle fiber activation