Accentuate the negative: when the weight is on the way down, your strength is on the way up. Find out why negative training can produce positive results

the old saying goes, "It's all downhill from here!" Usually meant to convey a sense of relief that the end is near, this axiom connotes blue skies and smooth sailing--assuming the road uphill was more difficult than the road heading south. Well, did you know that the simple act of walking downhill causes more damage to your leg muscles than walking uphill? For years, scientists have used downhill walking and running to study the effects of eccentric forces on muscle, because those eccentric (negative) forces have been shown to be the primary reason for exercise-induced muscle injury.

Now what does that mean to the average Jane? Not so much. To the weekend athlete? Not much more. But if you weight-train regularly to add muscle or enhance definition, you either focus on the negative or let the competition pass you by. Manipulating and maximizing the negative muscular contraction can be critical to achieving your fitness goals. Read on.

name that contraction

"Muscle either shortens, remains at the same length or lengthens during contraction, depending on the external load placed on it relative to the amount of force developed by the fibers," explains Ramey Benfield, PhD, research administrator at the Baylor College of Medicine in Houston.

In other words, if an external load applied to a muscle is equal to the amount of force being developed in that same muscle, there is no change in muscle length. This type of contraction is termed isometric. If the external force is less than the force the muscle is generating, there is a shortening of the muscle, called a concentric, or positive, contraction. And finally, if the external force is greater than the force the muscle is developing, the muscle lengthens and an eccentric, or negative, contraction occurs. In general, concentric contractions occur during the lifting of a weight, and eccentric contractions occur during the lowering of that weight.

let the negative force be with you

The idea behind negatives is simple, but humor me here. In a perfect negative resistance training world, you'd bypass the positive portion of a repetition by having someone lift the weight for you and then concentrate your energy on the negative, lowering portion of the exercise. What benefit does that have upon your muscle? Well, when you compare the forces being exerted during concentric, isometric and eccentric contractions, the differences are vast and worthy of note. NPC fitness competitor and model Sherri Newton says she incorporates negatives into her workouts to push her body through plateaus and bring up lagging bodyparts. "Negatives are great for training problem areas," she confirms. "And safe negative training shocks the muscle into action."

Benfield adds that the force developed during a concentric (positive) contraction is less than a maximum isometric force (simply supporting the weight with no movement). What's more, "the force developed during a negative contraction can exceed the isometric contraction by at least 50%!" Bottom line: If you base the amount of weight with which you train solely upon the concentric component capability, the force-generating capacity of your muscles will be less than maximized and your progress will be limited. So to truly adhere to the principle of overload--which says a muscle must work at a level beyond what it's used to in order to improve--it's only natural to incorporate negative training into your workout routine.

how to go negative

Most often, adding negatives to a training schedule is a spur-of-the-moment occurrence at best. Perhaps one time at the gym you noticed two women at the preacher bench, and just when the one lifting failed concentrically, her partner said, "Let's do some negatives," then proceeded to take her through the onslaught, which completely fatigued her biceps. This spontaneous approach to negatives happens quite often, but a more effective one would be to include negatives in your regular training program. Certain bodyparts and particular movements lend themselves well to negative training, so planning ahead makes better sense.

But wait, before we dive into all that, let's go back to those two women for a second. Isn't it interesting that, while the set would've normally been finished due to concentric failure, the working partner seemed to have additional gas in the tank for all those negatives? How? Because the eccentric capability always exceeds the concentric capability. When you think about it, how many times during your training do you perform a set of 10, 12 or 8, and because you can't concentrically do one more rep, you stop? Our muscles are naturally engineered to withstand more eccentric work, so why do we ignore that? Taking this to the logical extreme, you could use a certain weight for the concentric portion of the rep, hand the weight off, and then be handed another weight for the eccentric component. That probably isn't practical, but given how important negatives are, here are two more feasible alternatives.