1. Biceps and triceps —each denoting a type of muscle—are singular nouns that look like plurals. Bicepses and tricepses are the logical plurals, but they’re only rarely used

2. The Supergym manufactured by Artimex Sport is a multifunctional Swedish ladder designed to help you perform more then 100 exercises for all muscle groups (deltoids, pectorals, tricepses, latissimus dorsi, trapezius, Bicepses, flexors, abdominals, quadriceps, biceps femoris, gluteal muscles etc.)