Hey there I used to go to the gym frequently for almost 6 months, never caught anything. It's kind of a common rule/thought i guess to people that exercising while they aren't well makes the illness worse, therefore most people wait until they are completely better before going back to the gym. Plus who want to exercise when they aren't well? They would all be lying in bed. Most gyms have a cleaning spray and/or wipes to wipe down your equipment after you use it. Some people may not use this after they use a machine so what you should do is wipe your machine with the spray/wipe BEFORE and after use just to make sure. If there is no spray/wipes you should bring your own to be safe. Wipe your phone screen or any personal equipment you have brought too if you are concerned about it.you will be just fine dear have fun working out