Getty Images
Close up shot of a man rubbing his aching wrist isolated on white background
Body Ache Concept
Getty Images
BCU Microscopic view of heart muscle contracting
BCU Microscopic view of heart muscle contracting
Getty Images
People working out a YMCA gym
TS feet on stair climber, woman on treadmill, array of tv monitors in front of her, man works on back muscles, young man does pull ups, man does leg pushes
Getty Images
Charles Atlas Demonstrates Strength
Charles Atlas demonstrates strenth to older man and boy / a shirtless Atlas holds biceps up to show muscles and rips a phonebook in half (that was already torn).
Getty Images
Charles Atlas Demonstrates Strength
Charles Atlas talking to older man and 2 young men / Atlas takes his shirt off and holds biceps up to show muscles and tries to rip phonebook in half but doesn't actually do it.
Getty Images
Young Asian muscular man exercising dumbbell shoulder press in the gym, lifestyle sport and bodybuilding concept
Young Asian muscular man exercising dumbbell shoulder press in the gym, lifestyle sport and bodybuilding concept
Getty Images
A slender strong girl trains a triceps in a crossover in the gym.
A slender strong girl trains a triceps in a crossover in the gym, she bends her arms in the elbows. Fitness- concept of healthy lifestyle.
Getty Images
Young Asian muscular woman exercising dumbbell shoulder press in the gym, lifestyle sport and bodybuilding concept
Young Asian muscular woman exercising dumbbell shoulder press in the gym, lifestyle sport and bodybuilding concept
Getty Images
Carly and Tali perform dowl squat warm-ups.
Carly and Tali perform dowl squat warm-ups.
Getty Images
Wide frame. Dustin demonstrates dowl squat to class.
Wide frame. Dustin demonstrates dowl squat to class.
Getty Images
Male athlete taking bar and lifting weight during training with support
Strong man taking bar and lifting weight with supporting friend in gitness club
Getty Images
Strong male athlete adding weight plate to bar in gym
Strong man adding heavy weight in fitness club
Getty Images
Young sports woman is working out in gym. Cardio training. Running on treadmill.
Young sports woman is working out in gym. Cardio training. Running on treadmill. Healthy girl in comfortable sportswear running on the treadmill in the gym.
Getty Images
Muscular fitness woman trains triceps. Girl exercise with Cable Crossover in gym
Muscular fitness woman trains triceps, unbends her hands down. Fit woman exercise with Cable Crossover in gym.
Getty Images
Athletic young woman doing hyperextension with weighting at the gym.
Sporty young woman doing hyperextension exercises on trainer back machine in the gym. Athletic young woman doing hyperextension with weighting at the gym. Concept of sport.
Getty Images
Young Asian muscular woman exercising dumbbell shoulder raise in the gym, lifestyle sport and bodybuilding concept
Young Asian muscular woman exercising dumbbell shoulder raise in the gym, lifestyle sport and bodybuilding concept
Getty Images
Young Asian muscular woman exercising dumbbell shoulder raise in the gym, lifestyle sport and bodybuilding concept
Young Asian muscular woman exercising dumbbell shoulder raise in the gym, lifestyle sport and bodybuilding concept
Getty Images
Young fitness woman doing biceps curl with E-Z bar at the gym, fitness training concept
Young fitness woman doing biceps curl with E-Z bar at the gym, fitness training concept
Getty Images
Exercising with prosthetic leg.
Closeup side view of mid 20's man with amputated limb and carbon fibre prosthetic limb walking on a treadmill.
Getty Images
Man Doing Seated Side Stretches
Tilt down shot of active young man in virtual reality goggles sitting on mat and performing side stretches during workout at home
Getty Images
INTERVIEW: Camille Guaty on the Muscle Milk Light drink. at the Muscle
INTERVIEW: Camille Guaty on the Muscle Milk Light drink. at the Muscle Milk Women's Fitness Retreat at Beverly Hills CA. (Footage by WireImage Video/GettyImages)
Getty Images
World's Strongest Kids
EXCLUSIVE Giuliano Stroe aged 6 and his brother Claudiu, 4, show off their muscles and tricks at their home gym (August 9). The two brothers ,aged just 6 and 4, are trained intensively for hours each day by their father Iulian, 35. He is...
Getty Images
MS TU Semi dressed athlete sitting and flexing arm muscles in studio
MS TU Semi dressed athlete sitting and flexing arm muscles in studio