The Claim

In resistance-trained individuals, strength improvements are greater in exercises with lower movement complexity (e.g., machine-based) compared to higher-complexity free-weight lifts when volume and frequency are matched, and prior experience with the movement pattern is a stronger predictor of adaptation than biomechanical complexity.

Source: Equal-Volume Strength Training With Different Training Frequencies Induces Similar Muscle Hypertrophy and Strength Improvement in Trained Participants

What the research says

Supports is higher

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

Supports
68score
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

Among people who regularly lift weights, strength gains are larger when using simpler machine exercises than when using complex free-weight exercises, even when the total amount of work is the same, because prior practice with the movement matters more than how complicated the movement is.

See the scientific wording

In resistance-trained individuals, strength improvements are greater in exercises with lower movement complexity (e.g., machine-based) than in higher-complexity free-weight lifts, even when volume and frequency are matched, suggesting prior experience with the movement pattern is a stronger predictor of adaptation than biomechanical complexity.

Why this might work

When someone has practiced a movement before, their brain and muscles coordinate more precisely, allowing more muscle fibers to activate with less effort, which makes them stronger faster on that movement.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: Equal-Volume Strength Training With Different Training Frequencies Induces Similar Muscle Hypertrophy and Strength Improvement in Trained Participants

    People got stronger faster on machines like the chest press and hack squat than on free weights like the bench press and squat—even when they did the same amount of work—because they’d practiced the machine movements more often, not because the machines were easier.

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

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