Is weight training for 20 minutes 5 day a week too much weight training?

No, as long as you alternate muscle groups and aren't doing the same thing each day. You could just use each day to do something different, example - Monday - arms, Tuesday - legs, etc.

Its all about how you feel, but you don't want to hurt your muscles.

That makes sense. I was going to do the same thing every day (lulnges, squats, free weights for arms, etc.) but it makes sense not to. Thank you for your response!

Nope, not too much. Feel free to do more if your body can take it. Just remember to concentrate on keeping good form and working with the proper and most comfortable weight. And yes, alternate muscle groups. Upper body one day, lower body the next and a couple days of rest during the week is good.

Weight training really speeds up weight loss. At least it did for me. Good luck.

Rest days are important because they give a chance for your muscles to rebuild. It's on these rest days that your muscles have a change to repair and get stronger. Like other posters said, alternating muscle groups is a great way to make sure your body is getting that rest time.