Today I did dumbbell flies. INCLINE dumbbell flies, to be precise. I don’t remember the last time I did this exercise. I’ve been trying to expand my exercise repertoire, incorporating movements I’ve previously ignored for whatever reason.
Like many lifters who came of age during powerlifting boom of the early aughts, I fell victim to the Go Big or Go Home ethos, the notion that only heavy compound barbell lifts have any value, that anything else is a waste of time, that bodybuilding is for precious lil’ flowers who’re all show and no go. This, of course, is ridiculous.
Isolation vs Compound Exercises
Isolation exercises like dumbbell flies — exercises that work across a single joint, in this case the shoulder — have a place in every training program because of their ability to stimulate hypertrophy (that’s bodybuilder-speak for muscle growth). Several factors trigger muscle growth, one of them being the amount of time the muscle is placed under tension.
Think of a standard powerlifting style set of deadlifts, something like 3-5 sets of 3-5 reps. This low-volume/heavy weight approach will lead to big gains in strength due to the impact it has on the central nervous system (CNS), but it doesn’t necessarily lead to gains in muscle mass (if you’ve spent enough time at gyms, chances are you’ve seen examples of this phenomenon: slight individuals who top out at 140 lbs yet can lift an ungodly amount of weight). This is because those low-volume sets often don’t last long enough to adequately stimulate muscle hypertrophy.
Moderate-to-high volume sets of isolation exercises place the muscles under direct and near-constant tension, provided they’re performed properly. They’re also easier on the joints because of the lighter loads used. Halfway through my first set of DB flies, I could feel my pecs contracting with more force than I ever noticed before. This is another benefit of isolation work: because the exercises are less technically demanding, you can really focus on the mind-muscle connection.
More muscle, less joint stress. What’s not to love?