Though foot races were physically challenging, if successful, athletes could become very wealthy.

Like other obstacle races, runners navigate through various terrain and physically challenging obstacles.

Often, pianists find it easier to remember a very fast and physically challenging virtuoso piece, because there's so much practice involved.

"Besides being physically challenging, it is something that takes every bit of your concentration," he explained.

These boats are physically challenging because they're so heavy.

Consequently, training is often described as not only physically challenging, but also very stressful psychologically.

Therefore, they must participate in various physically challenging contests and win "food credits" for themselves and their team members.

She was recognized as one of the company's senior guides, leading many physically challenging mountaineering expeditions.

It's physically challenging, and Johnson wasn't small; he weighed about 240 pounds.

Ponting noted that he had never before worked in such a physically challenging environment.