Jack LaLanne official site
Jack LaLanne in the Navy
Here's a photo of Jack LaLanne in his Navy uniform, sometime around 1944. LaLanne was in the Navy during World War II and "served in the South Pacific, Guadalcanal and Suva," according to a 2010 blog post on his website. Jack LaLanne was born in 1914, so if this was 1944, he would have turned 30 the year this photo was taken.