The word "heavy" means something that has a lot of weight or is difficult to lift. It can also describe something that is serious or intense. Full definition
If you have a lot of heavy metals in your body, then your glutathione levels will most likely be insufficient. (thebrandwellnesscenter.com)
Weight Training loads depend on your goals - Light with higher reps to build muscular endurance and lower weight with heavy weights for building muscle and strength. (exercisegoals.com)