Q: After hearing good things, I got your Ultimate Fat-to-Muscle e-book. It looks fantastic, and I'm ready to start the workout (I need abs). One question: I understand how doing NA sets [one-second lifting and six-second lowering] causes muscle damage, which burns fat during recovery outside the gym--so why don't you have NA sets for the isolation exercises also, like concentration curls and cable crossovers? Can I use NA for those exercises too so I burn more fat?

A: Negative-accentuated, or X-centric, reps work so well on big multi-joint exercises because those create the most force overload on the MAJORITY of muscle fibers. That's because you can use the most weight thanks to muscle teamwork, or synergy.

For example, on bent-over dumbbell rows you involve the biceps, forearms and lats to target your midback muscle (trapezius). So with a negative-accentuated set you cause an abundance of fiber damage in the target muscle as well as some trauma in the "helper" muscles with the slow-lowering action. That goes for bench presses, squats, pulldowns, etc.

Stretch-position exercises--like overhead extensions for triceps, flyes for chest or incline curls for biceps--place unique stress on the muscle when it's elongated. While that creates microtears in fewer fibers than the big midrange exercise, you get “damage” near the hard-to-reach insertion of the muscle—lower triceps, inner chest, etc.

The last exercise for each bodypart, the contracted-position move, like crossovers for chest, involves fewer fibers. That makes these isolated moves less efficient for fiber trauma and more suited for occlusion, or blood-flow blockage, and heightened muscle burn.

Muscle burn is directly linked to higher growth hormone output, and GH is a potent fat-burner. So the more GH release you get, the faster your leaning out process will be. That's why we have higher reps—15 to 20—listed for most contracted-position exercise in The Ultimate Fat-to-Muscle Workout. For example, for chest you do…

Midrange: Incline presses, 3 x 9, 7, 5; 1 x 8NA
Stretch: Flat flyes, 1 x 9; 1 x 8NA
Cable crossovers, 2 x 15-20

But wait. NA sets last almost a full minute, so they will produce burn and GH release too. Couldn't you just do one high-rep set and one NA set for crossovers? You can, but the reason we don't suggest an NA set on the last exercise is that you may inflict TOO MUCH cumulative trauma. With an X-centric set on midrange-, stretch- AND contracted-position exercises, you can get extremely sore. Too much muscle damage can trigger overtraining and slow or even reverse gains.

Extreme soreness can be debilitating--if you've ever screamed trying to sit down the days after a squat workout, you know what we're talking about. Feel free to try NA on each exercise; you need to find the right amount of X-centric work for you. But for some it may be only one--on the big midrange exercise. Recovery is an individual thing, so you'll have to experiment to make the best gains.

Till next time, train hard--and smart--for BIG results.

Note: The Ultimate Fat-to-Muscle Workout e-book is now only $19.99. Our fat-burning nutrition guide with diets and training, X-treme Lean, is only $9.99 (less than 10 bucks)--or get it with X-traordinary Abs for only $19.99 (Double-Shredded Combo Offer at the X-Shop).

--Steve Holman and Jonathan Lawson
www.X-Rep.com