In addition to music, long walks and mountain climbing were among Planck's major recreational amusements. Both provided relaxation for him, even well into old age, from the stresses of his academic work. During the term he often set out into the surrounding countryside of Brandenburg. During vacation he went regularly on extended hikes in the Alps. As an eighty year old, he still was climbing peaks of over 3000 meters height.

Planck's ability to maintain his intellectual acuity, physical fitness, and professional productivity to a very old age was not just due to regular exercise but also to his daily routine. His day followed a strict schedule: breakfast was at eight o'clock sharp, after which he worked intensely until noon. That was how he was able to meet his many obligations. But Planck was no ascetic, by any means. He enjoyed the occasional glass of wine, cigar, and game of tarok-but everything was in moderation and within his family setting or among close colleagues and friends.