RSF Book Recommendation: REMIND ME, PLS

[Andy_S]

Chums:

A few months back, someone on here recommended a book. The book apparently researched various ancient societies from across the globe and showed how they were capable of much greater physical feats than we wimps of today.

IIRC, the example cited was the Roman legionnaires, who could apparently march the socks off any of today's armies.

Can anyone recall the title and/or author of this tome? A hat tip and a cookie for anyone who can name it.

TIA.