heavy weight, kill pump...?

[clockworks]

hey guys,
i've noticed something a little weird, just wanna get you guys' input on it. when i'm using moderate weight, after about 2-3 sets, i get a nice pump in whatever muscle i'm working out. but then if i do a couple of really really heavy sets afterwards (i.e. i'm straining my ass off to get like 3-5 reps and need a spot on the 5th-6th) it totally kills my pump. yall ever notice that? and if so, whats up with it?

thanks,
clocky baby

[little_indian]

Happened to me bro.IMO a pump depends on :
-How long the muscle is under stress.(It takes time for blood to get in).The longer the duration of the set,the more aerobic the effect is and the body pumps in blood to get the oxygen to your muscles.Heavy weights mean the effect is largely on the fast twitch fibers which work anerobically.So ur muscles are not really relying on oxygen and ur body does'nt pump in the blood.

-How good one's form is.Very heavy weights typically mean bad form(atleast relatively).So I guess the joints/supporting muscles are doing a significant amount of work here.
Just my opinion bro.I maybe wrong.

[Ocnorb36]

IMO powerlifters have some of the best form around. Any powerlifter will tell you without form comes injury and certain disaster. I state that because at least 1x per week I use a heavy load rotation (very heavey weights). That said, I get fantastic pumps with low or high reps. IMO volume sets the tone. You can lift a great deal of weight with few reps and exercies and get fantastic results and pumps but limit your time to 60 minutes or less (IMO!!!). The old cliche applies here too that all lifters get different results from different activities. Maybe you should reverse your workout to put the heavier work first and the lighter work last.

Oc