by Steve Holman, Iron Man Magazine
Q: I’m reading your X-Rep e-book [The Ultimate Mass Workout], and you list the Ultimate Exercise for each muscle. For lats it’s close-parallel-grip chins. I have a hard time with chins because I weigh around 220 pounds. Can I use the pulldown machine instead?
A: Yes, use the pulldown machine for now; however, once you’re strong enough, use the chinup bar.
I encourage moving the body through space and usually recommend other “free-weight” moves because there is more negative resistance than you get from a machine with a weight stack. On the pulldown machine, for example, the pulling-down stroke is actually heavier because of friction from the weight stack moving up the guide rods. Then, on the more important negative stroke, the resistance lessens because of the friction as the weight slides down the guides.
So on most machines the resistance curve is ass-backward—the positive is heavier and the negative is lighter. You’re stronger on the negative stroke, so it should be the opposite.
With chins the resistance is the same on both the positive and negative strokes. Research has shown that the negative is more important for increases in muscle size and strength in the myofibrils, so you don’t want the negative to be lighter, as it is on pulldowns. In a perfect world it would actually be heavier so you could take advantage of the muscle’s stronger eccentric capability.
That’s one of the big reasons so many trainees find that free weights are better than machines—weight-stack drag makes machine work somewhat less effective at stimulating the muscle myofibrils. In fact, you fail a rep or two early because of the positive drag on machines with weight stacks. The drag doesn’t happen, or at least is much less disruptive, on leverage machines like those made by Hammer Strength.
One way to compensate—and to get more tension time for sarcoplasmic growth—on pulldowns and other weight-stack-machine exercises is with end-of-set pure negatives. If you have a partner, do this: When you can’t get any more reps, have him or her pull the weight down for you so you can do a few five-second pure-negative reps. Your partner pulls it down, you lock in, and then you slowly release back to the top of the stroke. Repeat for three to five pure negatives. That will help offset the machine’s disadvantage and give you more size-and-strength success.