The Claim

After resistance training, regional muscle hypertrophy in the biceps brachii is not uniform, with greater growth occurring at the distal region (70% humerus length) when training in the initial range of motion (0°–68°) compared to the final range (68°–135°) in untrained young women.

Source: Training in the Initial Range of Motion Promotes Greater Muscle Adaptations Than at Final in the Arm Curl

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
46score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Description
1 study reviewed
In plain English

In untrained young women, resistance training that focuses on the beginning part of the movement causes more muscle growth in the lower part of the biceps compared to training that focuses on the end part of the movement.

See the scientific wording

Regional muscle hypertrophy in the biceps brachii is not uniform after resistance training, with greater growth occurring at the distal region (70% humerus length) when training in the initial range of motion (0°–68°) compared to the final range (68°–135°) in untrained young women.

Why this might work

When you lift weights with your elbow mostly straight, your biceps muscle is stretched more at the start of the lift. This stretch puts more pull on the part of the muscle closer to your hand, which triggers chemical signals that tell the muscle to grow more in that area. Over time, this makes the lower part of the biceps bigger than the upper part.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Training in the Initial Range of Motion Promotes Greater Muscle Adaptations Than at Final in the Arm Curl

    When women trained their biceps by lifting weights only in the first half of the motion (elbow mostly straight), their biceps grew more at the part closer to the hand than when they lifted only in the second half. So, where you do the exercise matters for where your muscle grows.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.