Muscle Building Techniques

There are other top two contenders: the gluteus maximus and the quadriceps. Human striated muscles don't differ in quality all that much, and other muscles typically have much smaller points of attachment (making them more likely to tear under stress), and/or less leverage. If you could somehow remove the muscles from their points of attachment and just measure how much they could lift, without the bones to help, other muscles would lose out against the gluteus maximus and the quadriceps. The rule of thumb is that the power of a striated human muscle is highly correlated with the effective cross-sectional area (for example, the number of fibers); the length of the muscle is meaningless. The two top contenders in this interpretation are the gluteus maximus (which tends to be fatty, inflating its diameter) and the quadriceps.

But there is one muscle that can generate the largest externally measurable force attributable to the action of a single muscle. However, it has the good fortune of being very broadly attached to a short-armed lever (a mechanical advantage counts for a lot).

The strongest muscle in the body is the masseter, the muscle you use to bite with. This powerful muscle is found on either side of the mouth.

Eskimos have (or used to have, when they subsisted on tough whale meat, etc.) twice the biting strength as those of us who live on tamer fare. According to the 1992 Guinness Book of Records, in 1986 Richard Hofmann of Lake City, Florida achieved a bite strength of 975 lbs. for two seconds. That's more than six times the normal biting strength of a human.

So remember the strongest muscle in the body is the masseter.