In the series “Our personal trainer“The Berlin fitness coach Sebastian Grüner helps us to become stronger, healthier and more beautiful. This article is part of TIME on the weekendissue 04/2026.

Hopefully over the past week you have trained your hamstrings as recommended. Now it’s the turn of the counterpart, a very special muscle group: the quadriceps, which, as the name suggests, consists of four so-called muscle bellies and takes up a large part of the front thigh. Taken together, it is considered the largest muscle group in the body (the largest single muscle is the buttocks). Gluteus maximus). The muscles of the front thigh are needed for running, jumping and standing up. So without them not much would work.