|Wennerberg left with Greta Andersen|
after her Luke Michigan 50 mile swim
Wennerberg was born in Chicago on June 20, 1932 and was introduced to swimming in Lake Michigan at the age of four. He was accepted into medical school at the University of Chicago, with an interest and focus on what would later become known as sports medicine, before he became interested in marathon swimming.
He moved to Hyde Park, in Chicago in 1969. He held night manager jobs, at the Illinois Athletic Club and the local Walgreens, so he could swim four to five miles each day. Beyond working and taking his daily swims, he was coach and trainer to IMSHOF swimmers Ted Erikson (the first double-crosser of the English Channel) and Dennis Match and ISHOF/IMSHOF hall-of-famer Jon Erikson., Wennerberg also traveled to Canada’s La Tuque, where he coached and explored marathon swimming. He developed a keen interest in cold water swimming, which is an element he brought to his coaching. Cold water swimming became a norm for him, as he had swum in Lake Michigan every single day of the year for many years. He was so devoted to his daily regimen that he would take an ice pick or axe to chip away ice from the lakefront, to gain access to the water.
In 1974, he wrote “Wind, Waves, and Sunburn,” a book chronicling the history of marathon swimming. He was inducted into the International Marathon Swimming Hall of Fame, in Fort Lauderdale, Florida, in 1977.