The soldiers jogging through the woods wear plain blue suits for jogging. Actually, the jogging suits used at that time (and for years to come) were made by Adidas and had the trademark stripes down the arms, and a light blue shoulder area (the rest of the suit being darker blue). This suit was introduced not until 1986. Back in 1983, the standard workout outfit for German military was plain dark blue, as correctly displayed in the picture.