i used to run but due to awful shin splints i haven't been going. now realised i havent been exercising for about a year! am a member of a gym and am free on mondays , tues lunchtimes and Thursday evenings. So my plan is to exercise at those times. I want to build back up to running but treadmill to start with. Any knowledgeanle fitness types able to suggest what i should be doing in the gym?