A Quick Recap
This blog is all about the types of muscle contraction – the difference in short and lengthened movements, and how it impacts your training across the spectrum of variables.
Lengthened Movements = Extremely demanding (very often compound movements, though not always)
– Back Squat, Deadlift, Good Morning, Overhead Tricep Extension
Short Movements = Much less demanding (very often single joint isolation movements, though not always)
– Leg Extension, Lateral Raise, Any Type of Row
Short Overload Movements
One of the defining characteristics of a “short overload” movement is that it is hardest at the “contracted” portion of the rep.
Contracted Portion Of A Rep
You can more easily think of this as the place where you would squeeze to feel the muscle work, or when the muscle gets “short.” These types of muscle contraction can be seen in the below exercises.
Row or Pulldown: portion of the rep where the hands are closest to the body
Lateral Raise: top of the rep where the arms are about parallel to the ground
Stretched Portion Of A Rep
For these short overloaded movements, you can probably feel that there is significantly less of a challenge at the “stretched” position.
Row or Pulldown: portion of the rep where the arms are extended
Lateral Raise: bottom of the rep when the arms are hanging by the sides of the body
In the example of the DB Lateral Raise, there is actually zero tension on the side delts at the bottom of the rep (because the arms are just hanging with gravity).
Failing Short Movement Reps
Another characteristic of short overload movements is that when you “fail” to achieve a full rep (i.e. the top of the lateral raise), you would still be able to achieve 90% of the rep, then 80% of the rep, then 70% of the rep… so essentially you will only gradually lose range-of-motion rep to rep.
In contrast to short movements, think about a lengthened movement like a Squat.
Tension At The Bottom
All of the tension in a squat exists at the bottom (when the glutes and quads are stretched under load) and in the mid-range (right as you initiate the upwards path).
There is literally zero tension at the top of the rep (you’re just standing there, with the legs locked out, joints stacked), which is the complete opposite from what we just talked about.
Failing Lengthened Movement Reps
Think about what would happen if you barely made a squat rep, then went back down to attempt another. Do you think you would get 90% of the way up? Then, do it again and get 80% of the way up?
No chance, right?!?
Instead, you would go back down to attempt another squat and you would get buried at the bottom. This is the definition of a lengthened overload movement. A Bench press would follow this same curve.
Along the same lines, think about an RDL. There is no tension on the hamstrings/glutes at the top (we’re just standing there holding a barbell), but tons and tons of tension at the bottom, as we are in this deep stretch position.
Feeling The Difference
Inherently, you can probably feel that these lengthened movements are just more brutal, cause more soreness/fatigue, and require a much higher degree of psychological arousal before beginning a tough work set.