Most bodybuilders pay very little attention to isometric contractions, yet when they get ready for a competition, they spend many hours in front of the mirror, posing. Many of us know that posing is extremely fatiguing and often neglected; but posing can actually add inches, according to new research. 

Sixteen young men were allocated to a training or a control group. The training group conducted a 12-week, three-day-a-week training program that consisted of four-second maximal voluntary contractions of elbow flexors and extensors.

Basically, the men would spend time simultaneously contracting their biceps and triceps. Muscle strength and thicknesses of biceps and triceps were measured before intervention and after four and 12 weeks. 

At the end of the study, muscle size also significantly increased in both biceps (+4%) and triceps (+4%) at 12 weeks. Agonist EMG activities during maximal voluntary contractions significantly increased in both elbow flexors (+31% at four weeks and +44% at 12 weeks) and extensors (+27% at four weeks and +40% at 12 weeks), without changes in antagonist involuntary coactivation level in both muscle groups. This study shows that isometric contractions can increase strength and muscle mass.