I talk often about the different phases of the lift (eccentric, bottom, concentric, top), but have gotten a lot of questions recently by people who are unfamiliar with the terms altogether and realized that I’ve never given a definitive breakdown of these concepts. Additionally, I’ve discovered that much of the confusion comes from the comparison across two, totally separate exercises. What do the eccentric or concentric phase have in common between, let’s say, the bench press and the upright row? Or the bench press and the stiff legged deadlift, for that matter. In this article I will break all of this down and hopefully leave you with a phD in bro science on the different phases of the lift.
The Eccentric Phase
The eccentric phase, also known as the lowering or negative phase, occurs when the muscle is actively lengthening under tension. In contrast, the concentric phase, or the lifting or positive phase, occurs when the muscle is shortening while generating force.
Examples:
Bicep Curl Eccentric Phase : When lowering the dumbbell or barbell back down after curling it up towards the shoulders.
Squat Eccentric Phase: The downward movement as you bend your knees and hips to lower your body towards the ground.
Chest Press Eccentric Phase: The lowering of the weight towards the chest by bending the elbows and lengthening (stretching) the chest muscles.
Deadlift Eccentric Phase: Lowering the barbell from a standing position to the ground. This lowering phases will create a stretch in your hamstrings if performing a stiff legged version of the deadlift.
In all these examples, the eccentric phase involves the primary muscle group lengthening as the lifter gives in to resistance (gravity, weights, or body weight). During this phase, muscles work eccentrically to resist the load and control the movement.
The Bottom Range Of Motion
The bottom range of motion (ROM) refers to the point in a movement or exercise where the targeted muscle or joint is at its most stretched or elongated position. I like to call this the stretch position.
Examples:
Bicep Curl: The bottom range of motion is when the arms are fully extended and a stretch is engaged in the biceps.
Squat: The bottom range of motion is when the thighs are parallel to the ground or when the hips are below the knees.
Chest Press: The bottom range of motion is when the weight is closest to the chest.
Deadlift: The bottom range of motion is when the weight is closest to the ground, or even touching the ground. If performing a stiff legged variation, it’s the point where the hamstrings are the most stretched/lengthened.
The Concentric Phase
The concentric phase involves the muscles actively shortening to generate a contractile force in the muscle, in order to move the weight or body against gravity/a mechanical resistance.
Examples:
Bicep Curl Concentric Phase : When curling the dumbbell or barbell upwards towards the shoulders.
Squat Concentric Phase: The upward movement as you straighten your knees and hips to return to the starting position.
Chest Press Concentric Phase: Pushing the weight up from the lowered (stretched) position until the arms are fully extended.
Deadlift Concentric Phase: Standing up with the barbell from the lowered position.
The Top Range Of Motion
The top position is usually where the muscles are under the most tension and where the muscle fibers are fully contracted. It is the moment when the exercise reaches its peak or when the targeted muscles have achieved their maximum engagement for that particular movement — but not always.
Consider the example of the hack squat (or any leg pressing movement for that matter). At the top of the range of motion, we aren’t in a particularly contracted position. That actually happens at the bottom of ROM.
Examples:
Bicep Curl: The top range of motion is when the biceps are fully contracted and a the hands are closest to your shoulders.
Squat: The top range of motion is when you are fully standing. Notice how the top range of motion for leg pressing motions (pressing against the ground) that the top range of motion is not the most muscle contracted position. Unlike the example of the bicep curl.
Chest Press: The top range of motion is when the arms are fully extended and your chest muscle are fully contracted.
Deadlift: The top range of motion is when you are standing upright with the barbell lifted off the ground.
Putting It All Together/TLDR
In a nutshell I like to think of each phase of the lift by these cues.
Eccentric phase- Active muscle lengthening phase
Bottom ROM - Stretch Position
Concentric phase - Active muscle contracting phase
Top ROM - Contracted Position
