I am fasting for the month of ramadan. i do not eat or drink from sunrise to sunset (4am - 830pm). but i usually do muscle workout during. i am hearing rumors that working out during fasting hours does not gain muscle and is bad. is this true?

Muscle mass is: not the only reason to workout but this will still be helpful even when fasting. Workouts help w/detox and circulation, mood, etc. Check w/doc to make sure you are healthy enough for this sacred fast. Peace and good health.

You can gain muscle: mass during Ramadan, but it may not be wise to try so hard. Your body is adjusting to fasting, which means calorie restriction in your case, during significant hours of the day. Your body will steal from its fat reserves during and after your workout, but you'll already suffer the effects of reduced calories. Lifting weights might be more hazardous. Take it easy until Ramadan is over.

Possibly: While fasting, you are becoming dehydrated. If you are doing a hard weight training workout, you are breaking down muscle to then build it up, and the lack of water and increased waste products from muscle can be hard on your kidneys and can even be damaging. Better to stick to cardiovascular exercise or low impact exercise like swimming or rowing and saving weight training for after Ramadan.