If you're new to strength training, having more tiny blood vessels around your fast-twitch muscle fibers might help those muscles grow more when you start working out.

31

Pro

0

Against

Evidence from Studies

Supporting (1)

31

Community contributions welcome

31

Influence of intramuscular steroid receptor content and fiber capillarization on skeletal muscle hypertrophy

Cross-Sectional Study

Human

2024 Jun

The study found that people who started with more capillaries around their type II muscle fibers gained more muscle in those fibers after training, which is exactly what the claim says.

Contradicting (0)

0

Community contributions welcome

No contradicting evidence found

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Source Study

Influence of intramuscular steroid receptor content and fiber capillarization on skeletal muscle hypertrophy

Score: 31

DOI: 10.1111/sms.14668

Similar Assertions

If you're new to working out, doing leg exercises for 10 weeks can make one of your big thigh muscles grow bigger, even if the individual muscle fibers don't get thicker.

31

0

76%

After about 10 weight workouts, your muscles don’t just look puffy from water anymore—they actually start getting bigger because the muscle fibers themselves are growing.

1

0

75%

When adults lift heavy weights, their fast-twitch muscle fibers grow much more than their slow-twitch ones, based on several studies.

26

0

73%

Even though muscles got bigger, the actual muscle fibers didn’t get thicker or change type—so the growth might be due to other factors like fluid or connective tissue.

25

0

73%

Some people get much bigger and stronger from weight training than others—even when they do the exact same workouts—because everyone’s body responds differently to exercise.

1

0

71%