I have just started getting into cycling again and a little bit of running (well jogging and walking really) after a development in stomach size (fat haha) Monday was my first day into somewhat of a routine where I had ridden 3.4 miles and ran 3.6 miles. Tuesday I did the same route cycling but did 4 miles running Wednesday (today) I did 11 miles steady cycling Without any dedicated warming up. The cycling was the warm up for the run, and then wednesday I didn't warm up at all. Should I really warm up? How can I do it? And what's its importance? The reason I ask is I want to reduce the chances of injuries and strain and I'm not sure, since I've never really been an active person.