How much time should i work out to lose weight ( men )?

That is up to you.: This site helps determine calories burned for > 100 activities: http://www.prohealth.com/weightloss/tools/exercise/calculator1_2.cfm There are 3,500 calories per pound. The number of calories you burn in working out will determine the rate (if consumption doesn't change). You put on muscle (which weighs more than fat) but which will ^ your metabolic rate.