A miscarriage can be a common cause of brown to black vaginal bleeding. Not all the women realize that they are pregnant until there is an abnormally heavy bleed particularly consisting of large clots or the color varying from the normal period blood.
Boost Your Metabolism in 15 Minutes 4 Moves to Rev Your Metabolism Kick calorie burning into overdrive with this quick full-body workout Read more: Exercises that Boost Your Metabolism - How to Boost Your Metabolism - Woman's Day.
1 Weight - Different tissues of your body contribute different amounts to resting metabolism. Muscle contributes more than fat per unit mass and, because it is denser than fat, muscle contributes much more per unit volume..  Body size - Metabolic rate increases as weight, height, and surface area increase.