It's been my first time working out in a few years. I started working out this monday, did all the upper body exercises and followed everything that my personal trainer had me do. Then I went back on tuesday, feeling some small muscle pains (Perfectly normal) and he told me it was best to do lower body exercises so I could get all my muscles used to the exercises again.. On wednesday I woke up and felt like crap I couldn't even move my arms at all.. Was feeling major upper body muscle pains.. I couldnt even talk on the phone or do any movement involving my upper body without feeling ALOT of pain (I wasn't feeling any lower body pains at all.. Just upper body). I know the first week is always the one where you are feeling most pain and it's really important for you to go in everyday so your muscles get used to the exercises, but I had no condition to even drive to my gym so I decided to stay home and take some Muscle Relaxers. Woke up on thursday feeling way better on the upper-body pains but I my legs felt like they were going to take a shit on me.. So i continued taking muscles relaxers throwout the day (1 pill every 6 hours) because i knew i had to go to the gym and put some work in.. So i finally started feeling way better and went to gym.. When I got there and finished my first exercise my arms felt like as if the muscles were locked and I felt tired.. I continued doing my exercises but I had NO strength at all to finish the sets.. I just wanted to know if the reason why I lost all my strength and what caused my muscles to "lock" up was the muscle relaxers, or the fact that I missed the 3rd day of workout and let my muscles "heal".. I'm sorry if im asking stupid questions but I have honestly been hearing different things from different people and wanted to know what my problem is so I can fix it.