The Importance Of Full Range Of Motion In Exercise
Full reps or partial reps? Each has a place in your training, but according to recent research, full range of motion (full repetitions) produces greater growth. The study entitled Muscular adaptations and insulin-like growth factor-1 responses to resistance training are stretch-mediated involved participants who trained for eight weeks, loading their quadriceps in a shortened knee flexion (partial rep) or lengthened (full rep) position, followed by four weeks of detraining. The control subjects were untrained. Each participants quadriceps strength, vastus lateralis architecture, anatomical cross-sectional area and serum insulin-like growth factor-1 (IGF-1) were measured before the study and at weeks 8, 10, and 12.
The results: muscle length increased 29% versus 14%, muscle diameter increased 53% versus 18% and muscular strength increased 26% versus 7% all in favor of the full range of motion.
While training your body with a smaller or limited range of motion (partial reps) may allow you to use more weight, it will not help you prepare for the many functional tasks your body will encounter daily. Partial rep training may also be dangerous for you when you need to perform any full range movement. While you may include partial rep training to supplement training, always include full range of motion exercises as the core of your program. You may need to use more partial rep training if you have limiting ROM factors such as a previous injury, structural discrepancies, or simply that you have not exercised before using a full range of motion. Always strive to slowly and safely increase your range of motion until you reach full range.
Be careful not to sacrifice form (or shorten your ROM) for the sake of weight or speed. Don’t race through an exercise in an effort to lift more weight, or to reach a repetition number at any cost. Doing so will always ruin your form and sacrifice the positive benefits of the exercise and you will be wasting your effort and time. Always use full range of motion even if you have to cut back on the amount of weight you use. Your size and strength will increase more rapidly.
While it may be easier to lift more weight when your movements are shortened, remember the research supports training muscles at longer lengths produces greater growth. In this particular case, performing leg exercises at longer lengths (ROM) resulted in markedly greater hypertrophy across all aspects. If maximizing gains in size and strength is your goal, make sure that the majority of your exercises are taken through a complete and full range of motion that includes the long-length (extended) position, with a few sets dedicated to working at shorter, partial reps to strengthen supporting tissues.