The Claim

Supervised static stretching of the pectoralis major muscle for 15 minutes per day, 4 days per week over 8 weeks is associated with muscle hypertrophy, as indicated by an increase in muscle thickness of approximately 5.6–6.5% in recreationally active adults, with no statistically significant difference in hypertrophy compared to resistance training.

Source: Influence of 8-weeks of supervised static stretching or resistance training of pectoral major muscles on maximal strength, muscle thickness and range of motion

What the research says

Supports is higher

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

Supports
47score
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.

Correlation
1 study reviewed
In plain English

Stretching your chest muscles for 15 minutes, 4 times a week for 8 weeks, might build muscle just as much as lifting weights — studies say it could increase muscle thickness by around 6%.

See the scientific wording

Supervised static stretching of the pectoralis major for 15 minutes per day, 4 days per week over 8 weeks is associated with muscle hypertrophy, increasing muscle thickness by approximately 5.6–6.5% in recreationally active adults, with changes not significantly different from those produced by resistance training.

What the research says

1 study
  1. Study: Influence of 8-weeks of supervised static stretching or resistance training of pectoral major muscles on maximal strength, muscle thickness and range of motion

    The study found that stretching the chest muscles daily for 8 weeks made them grow just as much as lifting weights, with no real difference between the two.

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.