Performing biceps curls in the starting position (i.e., muscle stretched) resulted in greater growth than in the finishing position (i.e., muscle contracted). 1 RM strength was greater for biceps curls in the starting position compared to the ending position.
SUMMARY OF PARTIAL REP EXERCISES FOR BIGGER BICEPS
- Performing biceps curls in the starting position (i.e., muscle stretched) resulted in greater growth than in the finishing position (i.e., muscle contracted).
- 1 RM strength was greater for biceps curls in the starting position compared to the ending position.
In the past, if you were not doing a full range of motion, you didn’t know anything about building muscle! You need a full range of motion for muscle growth, bro!! There has been much controversy regarding a full range of motion vs. a partial range of motion.
A partial rep or partial range of motion is, just like it sounds, a half rep. A full range of motion is considered a superior way to gain muscle because you stretch the muscle. Studies have found that doing a full range-of-motion squat resulted in greater muscle growth than a partial range-of-motion squat. (Bloomquist et al., 2013; Kubo et al., 2019)
However, the partial range of the squat was not in the muscle-stretched position. They started in the standing position and went halfway down. The muscles are stretched in the bottom position of the squat.
The stretch in the muscle is a key factor for increasing muscle growth. A stretched muscle has been found to increase metabolic stress and IGF-1, which results in greater muscle growth. (Kooistra et al., 2006; McMahon et al., 2014) Animal studies have found that stretching the muscle has also increased muscle protein synthesis and muscle mass. (Warneke et al., 2022) Other exciting research has shown that stretching without weights can increase muscle growth.
NOT ALL PARTIAL REPS ARE THE SAME
You can do a partial rep and still stretch the muscle. The beginning phase of the movement in which the muscle is stretched has been found to result in greater muscle growth than when the muscle is shortened. Here are a few studies showing the superiority of stretched muscle for greater gains:
· Quadriceps showed greater muscle growth for performing a partial range of motion at the beginning compared to the end. (McMahon et al., 2014; Pedrosa et al., 2022)
· A study found that biceps curls performed at the beginning range of motion (i.e., muscle stretched) resulted in more muscle gains than those performed at the end range (i.e., muscles contracted). (Sato et al., 2021)
Calf raises performed with a stretch at the beginning resulted in greater calf muscle growth than performed at the end. (Kassiano et al., 2022)
BEST WAY TO DO BICEPS PREACHER CURL
Researchers had subjects do biceps curls subjects train with seated dumbbell preacher bicep curls for eight weeks. They either trained in the starting position (i.e., the bottom position in which the muscle is stretched) doing a half-rep, or they trained in the finishing position (i.e., the top position of the curl) doing a half-rep. They trained their biceps three times per week. The subjects trained to complete muscular failure each set.
At the end of the study, those that did dumbbell preacher curls at the bottom or stretched biceps position had greater increases in muscle growth than those doing the same routine in the muscle top position or contracted position. They also found that performing biceps curls in the stretched position resulted in greater increases in maximal strength. (Pedrosa et al., 2023)