The Claim

Training the elbow flexors through the initial range of motion (0°–68° elbow flexion) for eight weeks, three times per week, results in greater hypertrophy at the distal region of the biceps brachii (70% humerus length) and greater increases in one-repetition maximum strength compared to training through 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.

Cause and effect
1 study reviewed
In plain English

In untrained young women, performing bicep exercises using only the first half of the movement range for eight weeks leads to more muscle growth in the lower part of the biceps and greater strength gains than using only the second half of the range.

See the scientific wording

Training the elbow flexors through the initial range of motion (0°–68° elbow flexion) for eight weeks, three times per week, leads to greater hypertrophy at the distal region of the biceps brachii (70% humerus length) and greater increases in one-repetition maximum strength compared to training through 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, which creates more pull and stress on the lower part of the muscle. This stress tells the muscle cells to build more protein and grow bigger in that specific area. The bigger lower part of the muscle helps you lift heavier weights overall because it's stronger where the lift is hardest.

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

    This study found that doing arm curls with only the first half of the motion made the lower part of the biceps bigger and made people stronger, compared to doing only the last half of the motion.

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

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