Royalty free Effort image: Businessman playing tug-of-war with clones of self, digital composite

Royalty free Effort image: Identical businessmen playing tug-of-war for the same side

Royalty free Effort image: Businessman lifting block on back

Royalty free Effort image: Mature man lifting dumbbell, looking at camera

Royalty free Effort image: Illustration of Businessman Balancing and Juggling Balls, while Blindfolded

Royalty free Effort image: Dogs Running through Snow, Ontario, Canada

Royalty free Effort image: Man Jogging Past Fire Hydrant and Crosswalk Sign at the Entrance to Granville Island, Vancouver, Bri

Royalty free Effort image: Cyclist Holding Bike Above Head in Yoga Pose

Royalty free Effort image: Cyclist lifting Bike Above Head

Royalty free Effort image: Boy blowing up birthday balloons

Royalty free Effort image: People blowing up birthday balloons

Royalty free Effort image: Woman blowing up birthday balloons

Royalty free Effort image: Teenage girls holding umbrella on windy beach

Royalty free Effort image: People blowing up birthday balloons

Royalty free Effort image: African woman leaning against tree in park

Royalty free Effort image: African man running uphill

Royalty free Effort image: Hispanic boy playing trumpet

Royalty free Effort image: Mixed race woman measuring her waistline

Royalty free Effort image: Hispanic boy playing trumpet

Royalty free Effort image: Woman exercising on gym equipment, personal trainer assisting her

Royalty free Effort image: Business people tugging rope

Royalty free Effort image: Man about to throw a discus

Royalty free Effort image: Teen boy on bike jumping

Royalty free Effort image: Teen boys riding bikes