The Rules of Mechanical Advantage: How Wide is Too Wide?

It’s generally a bad idea to create strict rules to live by in the weight room – “I only do barbell exercises,” “I never wear a belt,” or “I don’t lift heavy weights because I don’t want to get too big.” Stubbornly defining yourself by these rules, or putting yourself into a box, can preclude you from some benefits that you might otherwise experience.  Your rule might not apply as neatly to every body part or goal or movement pattern as you’d like to believe.  Having said that, I’m going to go out on a rather sturdy limb here and propose two new rules for you to follow in the weight room.  I’ll call them the “Rules of Mechanical Advantage.”

 

Rule #1 – For all multi-joint/compound lifts, choose the position (hand width, foot width, etc.) that allows you to move the most weight possible for your desired rep range (you have an advantage over the weight)

 

Rule #2 – For all single-joint/isolation lifts, choose the position/path that makes a given weight feel as “heavy” as possible (give the weight an advantage over you)

 

The point of resistance training is to stress, or overload, the muscle. You place a stimulus on the muscle that it cannot handle, and the muscle adapts accordingly. Therefore, your only goal should be to find ways to challenge the muscle’s ability to perform.

 

Definitions:

Multi-Joint or Compound – movements that involve two or more joints working at the same time (e.g. knees and hips; shoulders and elbows)

  • Examples of compound movements include the squat, lunge, deadlift, bench press, lat pulldown, and shoulder press

Single-Joint or Isolation – movements that involve (or isolate) only one joint at a time (e.g. elbows only, knees only)

  • Examples of compound movements include the bicep curl, tricep pushdown, lateral raise, pec fly, and leg extension

 

A deeper look at the rules.

 

Rule #1 – At some point you’ve probably considered the difference between different hand placements on bench press or stances on squats. You may have heard that a wider grip will help your muscles develop differently, or that a narrower stance will target a specific muscle. At the end of the day, all you should really be concerned with is how you can place the biggest stress on the movement pattern you’re performing. Which hand position allows you to move the most weight through a full range of motion? Which foot width in your squat stance allows you to load the most for your predetermined rep range? In the vast majority of situations, these are the positions you should stick with. More overload leads to a better stimulus for improvement, and unfortunately you can’t decide how to shape your muscle – you can just make it bigger.

 

Rule #2 – If you approach isolation lifts with a similar goal – to use as much weight as possible – you are going to defeat the purpose of that lift, or you’re going to increase the likelihood of injury. Think of barbell curls where the knees and hips dip and extend to get the weight moving, the low back extends, and the shoulders flex to help get the weight up. This is hardly isolating the biceps, and it’s also likely that you’ll tweak an elbow or your low back. Using momentum to lift the weight is known as cheating, and although there are times when cheating can be used effectively it is generally unnecessary. Instead, you should make a given weight work for you. You can achieve this by moving the weight in a slow and controlled manner, and by making sure you maintain the correct body position throughout the set. One of the other ways we typically cheat on isolation lifts is by shortening the lever arm to make the lift easier. This would be like bending your elbows on a dumbbell fly rather than keeping them close to locked out. Obviously you can lift more weight as you creep toward performing a chest press, but the whole point of the exercise is to stress the pecs – not to lift a lot of weight.

 

BENCH PRESS

 

 

One study looking at the effect of grip width on muscle activity in the bench press concluded that somewhere between 165-200% of biacromial breadth (the distance between your acromion processes, the bone you can feel at the top of your shoulder) offers the best activation of the prime movers (pecs and triceps). This should look something like the the two bottom pictures where the forearms are pointing straight up and down. A grip width that was more narrow did not provide as much muscle activation, and a grip that is wider than 200% (as pictured above) is typically a weaker position. The advantage of a wider grip may be the reduced vertical displacement needed to complete the lift, and this may be an advantage to some lifters in powerlifting competitions. Generally speaking, we would rather have greater muscle activation and a greater range of motion, and we get that by using a position that leaves our forearms perpendicular to the ground at the bottom of the lift. Another common concern for grip width is changing the shape of the muscle as it grows. It is not uncommon for lifters to believe that a wider grip will lead to wider pecs. This is simply not true, as the shape of the muscle growth is for all intents and purposes genetically predetermined. All we can do is give it the stimulus to grow (through proper overload and range of motion), and wait to see what happens.

 

LAT PULLDOWN

 

 

We can apply similar principles to the lat pulldown. One study looked at the effect of grip width on muscle strength and activiation, and concluded (similarly to the bench press study) that a grip between 100-200% of biacromial width provided the highest muscle activation. Again, we can apply a simple visual cue to this position and aim for a grip width that keeps the forearms perpendicular to the ground (pointing straight up and down) in the bottom position of the lat pulldown. You can also clearly see the benefit of increased range of motion between the “medium” grip versus the wide grip pictured above. Anecdotally, the weight had to be lowered to take the wider-grip pictures for this lat pulldown series as well as the bench press series discusses earlier. As mentioned with bench press, a wider grip with lat pulldowns will not lead to wider growth of the lats. Only proper overload and range of motion will lead to growth, and the particular shape and width is largely predetermined by your genes. In general, males can find a proper lat pulldown position by placing their hands just outside the bend of a standard pulldown bar (as pictured), and females will typically place their hands just inside the bend of the bar.

 

LATERAL RAISES

 

 

On the flip side of this coin, we have isolation lifts. With compound lifts, like bench press and lat pulldown, we want to find a position where we can move the most weight. With isolation lifts, we want to make a given weight as “heavy” as possible. The way we can make a given weight more challenging is ensuring that our technique is perfect (only one joint moving, slow and controlled speed of movement, full range of motion), and by making sure we exploit some basic biomechanical principles. In the example above, we want to make the lever arm as long as possible, and create the longest moment arm possible. The moment arm is the distance between the axis of rotation (the shoulder in this example) and the line of force acting on the load (this force will always be directed straight down when using free weights). So the “heaviest” part of this exercise is when the dumbbell is furthest away from the shoulder on a plane parallel to the ground (horizontally). When the dumbbell is in the bottom position (hanging next your thigh) the moment arm is virtually zero since there is no horizontal distance between the axis of rotation and the load.

The practical application for this exercise is to keep the arm as long as possible, or to not bend the elbow. As you can see in the pictures above, the bent elbow position will allow you to lift a heavier weight. However, this doesn’t necessarily lead to more overload of the deltoids. Overloading the deltoids is the point of the exercise, not to lift more weight.

 

CURLS

 

We can apply these same principles to curls as well. As we go up in weight, we are forced to sacrifice form and technique. You can see in the picture on the left that the elbow moves forward with heavier weight to compensate. The picture on the right shows proper form and a maximized moment arm between the dumbbell and the elbow. When the weight is too heavy on curls, we might also see the shoulder drop (as pictured) so that the lifter can sneak under the weight rather than lift it with the biceps. Similarly, many lifters will bounce through the knees and hips to use momentum. The point here is to overload the biceps by making sure that’s the only muscle lifting the weight. Sure you can stress the biceps when your elbow moves forward, you dip you knees, or you drop your shoulder, but all of those movement flaws but you at risk for injuries. Tweaking your shoulders doing curls is not a very efficient way to grow, so keep your form strict on these isolation exercises and hit the muscle you’re targeting.

 

These are just a few of the worst offenders, but these ideas can be applied to any other lifts. The point of lifting weights is to stress the muscle and let the body adapt. Whether that’s adapt by getting stronger or getting bigger or improving metabolic function, it’s important to keep these techniques in mind. One of the most important arguments for maintaining a full range of motion at a slow, controlled pace is that it will help you avoid injury. You can’t lift and grow if you’re hurt. So next time you’re in the gym apply these rules to make your lifts more effective and more efficient.

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