"while challenging" is a correct and usable sentence in written English.
For example: "I enjoyed learning a new language while challenging my problem-solving skills."
Stanley H. Kaplan became eminent in the world of test taking while challenging those eminent in the world of test making.
The jury said his work engaged with contemporary culture, while challenging conventional aesthetics.
Mr. Kyllo conditionally pleaded guilty while challenging the use of the imager as an unconstitutional search.
Beauty gigs, while challenging, have to come second for an actress, she says.
Mr. Lerner's client entered a conditional guilty plea while challenging the use of the thermal imager.
European officials have stood firm while challenging opponents to suggest an equally effective alternative.
While challenging the status quo, the use of turntables as an ensemble instrument is in fact nothing new.
Speaking English with the Villanueva kids, while challenging at first, helped my brother learn the language faster.
"He knocked the guy out, for heaven's sake, while challenging a chargedown with his arms down by his side".
But while challenging shadow chancellor Ed Balls, McCluskey does not question his suitability as chancellor-in-waiting.
His "Conflicts Forum", based in Beirut, aims to "engage and listen to Islamists, while challenging Western misconceptions".
