Ключевые слова: arm, background, black, bright, closeup, emergency, equipment, exercise, expander, expanding, fitness, flex, flexor, flexors, glass, grip, hand, handle, healthy, isolated, light, man, metal, muscle, muscular, nobody, object, physical, power, resistance, sport, spring, springs, squeeze, steel, strength, strong, style, technology, tool, trainer, training, white, work,