How important is exercise technique in strength training? This may seem like a silly question, but I see a number of competitive bodybuilders at the gym, whose workouts are obviously effective, and they are ignoring all of the technique rules I have read about. For example: no full range of movement, using momentum, swinging posture, high reps, not going to failure, not slowing the movement in the extension phase. Since these workouts seem to be effective, I am starting to wonder if I'm being excessively strict about exercise form with myself and my clients. Can you clarify this matter please?
One can never go wrong by emphasizing proper technique in weight training movements. Proper technique results in two main benefits: 1) a muscle is developed through a full range of motion (ROM) and 2) the chance of injury caused by excessive load or contraindicated technique is reduced.
Competitive bodybuilders are notorious for using limited range of motion in many exercises. This may be a result of their loss of flexibility after training this way for years and/or their aim of using a heavier resistance to “shock” the muscles into growth. In order to use a heavier resistance than can be handled properly through a full ROM, one must “cheat.”
If you can curl 75 pounds for 10 reps using perfect form, no doubt you can use much more (100 pounds or more) in a limited ROM or “cheating” manner. Let’s say you don’t totally extend your elbows. Perhaps you combine this with swinging the bar upward via lots of torso action. Using these or similar techniques allows more weight to be used, but you’re working through a partial ROM. Train like this long enough, and you may create greater hypertrophy. But you’ll probably also experience a decrease in your elbows’ ability to fully extend.
After years of trying to convince the public that lifting weights does not cause one to become “muscle bound,” we have to acknowledge that loss of flexibility can occur if exercise technique is compromised.
No doubt heavier resistance, in both concentric and eccentric muscle actions, can stimulate additional muscular growth. In advanced athletes, some limited ROM actions may contribute to increased overall strength (and theoretically, growth). This increased strength should allow the use of heavier weights when returning to full ROM exercises, provided flexibility has not been inhibited.
As far as reps, we know that for the most part:
- Low (1-6) reps, high (85% and above) load tends to improve strength.
- Medium (8-12) reps, medium (70-85%) resistance tends to stimulate muscle hypertrophy.
- High (>15) reps, low (<70%) load tends to improve muscle endurance, (without much strength improvement or hypertrophy).
One does not need to “go to failure” in order to improve any of the muscular qualities (strength, hypertrophy, muscular endurance).
In traditional exercise execution, the eccentric portion of a lift utilizes the same amount of resistance involved in the concentric phase. There is no physiological rationale for performing the eccentric portion of a customary exercise slower than the concentric part. We know that eccentric muscle action requires greater resistance in order to demonstrate any positive effects. Slowly performing the eccentric portion of an exercise with a sub-max load is generally considered a waste of time.
You mention the bodybuilders you’ve observed seem to be engaged in “effective” workouts. This is not defined in your question, so I can’t say much more about cause and effect. Do keep in mind that physical results in competitive bodybuilding, where the primary focus is hypertrophy, can be severely influenced by the use of prohibited substances. Combine heavy training (which may or may not include the techniques you mention), large amounts of protein and anabolic androgenic steroids, and muscle growth may occur, regardless of exercise technique.
I know of no studies that have examined the effects of proper versus cheating techniques and the resultant muscular consequences. As a bit of general advice, you should consider the level of training sophistication you and your clients exhibit and also take into consideration the training goals. There may be times when less than ideal technique can have a positive effect. But I would not suggest you train the general public in the manner you have observed and referenced.