Woman mountain biker rides single track trails at Kincaid Park in Anchorage, Alaska

Woman rides a full suspension mountain bike across a stream on the Devil's Pass Trail in the Chugach National Forest, Kenai Peninsula, South-central Alaska

A man and woman standing with their bicycles on a rocky ledge overlooking a view of the landscape; Tarifa, Cadiz, Andalusia, Spain

A man and woman on bicycles stand with a view of the ocean and coastline; Tarifa, Cadiz, Andalusia, Spain

Close up of muddy mountain bikers after a long ride on the Resurrection Pass Trail, Chugach National Forest, Kenai Peninsula, Southcentral Alaska

A male teenager rides a bicycle over a dirt jump and is airbourne 15 feet above the jump; Grand Junction, Colorado, United States of America

A young woman stands with her studded tire bicycle amongst the ice chunks in the Cook Inlet next to the Tony Knowles Coastal Trail, Anchorage, Southcentral Alaska, USA.

A young woman riding her bicycle on ice and snow next to the Tony Knowles Coastal Trail, Anchorage, Southcentral Alaska, USA.

A young woman pushes her studded tire bicycle amongst the ice chunks in the Cook Inlet next to the Tony Knowles Coastal Trail, Anchorage, Southcentral Alaska, USA.

Snowboarder in mid-air with blue sky and clouds; Lake Tahoe, California, United States of America

Side Angled View Of Sport Biker On Mountain Bike, Blur Action