The Claim

In resistance-trained men, a whole-body resistance training routine performed five days per week results in significantly greater increases in muscle thickness of the forearm flexors and vastus lateralis compared to a split routine training each muscle group once per week, following an eight-week training period.

Source: High Resistance-Training Frequency Enhances Muscle Thickness in Resistance-Trained Men.

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

If you're a guy who already lifts weights, doing full-body workouts five days a week will make your forearm and thigh muscles grow bigger than if you only work each muscle group once a week, after eight weeks of training.

See the scientific wording

In resistance-trained men, a whole-body resistance training routine performed five days per week leads to significantly greater increases in muscle thickness of the forearm flexors and vastus lateralis compared to a split routine training each muscle group once per week, after eight weeks of training.

What the research says

1 study
  1. Study: High Resistance-Training Frequency Enhances Muscle Thickness in Resistance-Trained Men.

    The study found that men who trained their whole body five days a week grew thicker forearm and thigh muscles more than those who trained each muscle group only once a week, which is exactly what the claim says.

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.