He first gained fame in his junior year, when he became the first (and to this day, the only) Cornellian to win the intercollegiate tennis championship.

An all-around athlete, Larned captained the St. Nicholas Hockey Club in 1896–97 and was also a horseman, golfer, and rifle shot.

He twice participated in the Wimbledon Championships, in 1896 and 1905, but could not match his success at home, losing on both occasions in the quarterfinals.

While serving in the war, Larned developed rheumatism in Cuba; rheumatoid arthritis later deteriorated his health forcing him to retire from tennis after losing the Davis Cup challenge round in early 1912.

On the evening of December 15, 1926, inside the private chambers of the exclusive Knickerbocker Club in Manhattan, the 53-year-old Larned committed suicide by shooting himself.

Among his strongest points are his forehand volley, which is very hard indeed, and his service, which is a capital one of the ordinary straight kind, and which he, as a rule, follows up to the net.