Sehr glückliche junge Athletin beim Ausfalltraining im Sommer auf einer Outdoor-Bahn. - Stockfoto & -bild

Lunges performed by a young female athlete while working out on an outdoor track in the summer.

Lunges performed by a young female athlete while working out on an outdoor track in the summer.

Very happy young female athlete performing high knees while working out on an outdoor track in the summer.

Very happy young female athlete performing lunges while working out on an outdoor track in the summer.

High knee exercises performed by a young female athlete while working out on an outdoor track in the summer.

Fitness girl with ultra violet dumbbells doing warm up on the sadium before training, stretching body muscles. Female athlete preparing legs for cardio workout. Active girl doing exercises outdoor.

High knee exercises performed by a young female athlete while working out on an outdoor track in the summer.

Very happy young female athlete performing high knees while working out on an outdoor track in the summer.

Healthy lifestyle young fitness woman running. Female runner practicing on running lane

EUGENE, OR - MAY 7, 2017: Runner heads down the river path at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.

EUGENE, OR - MAY 7, 2017: Runner Benjamin Mears comes through the tunnel at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.

EUGENE, OR - MAY 7, 2017: Runner heads down the river path at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.

EUGENE, OR - MAY 7, 2017: Official split point for half marathon and full marathon at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.

EUGENE, OR - MAY 1, 2016: Runner approaching the finish line on the track at Hayward Field during the 2016 Eugene Marathon, a Boston qualifying event.

EUGENE, OR - MAY 7, 2017: Runners cross a bridge over the Willamette River at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.

EUGENE, OR - MAY 7, 2017: Runners cross a bridge over the Willamette River at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.

EUGENE, OR - MAY 7, 2017: Runners cross a bridge over the Willamette River at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.

EUGENE, OR - MAY 7, 2017: Runner heads down the river path at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.

EUGENE, OR - MAY 1, 2016: Runner approaching the finish line on the track at Hayward Field during the 2016 Eugene Marathon, a Boston qualifying event.

Official split point for half marathon and full marathon at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.

Official split point for half marathon and full marathon at mile 10 of the 2017 Eugene Marathon race held on the University of Oregon campus.