Arm-Exercises-That-Really-Attack-Underarm-Fat-Photo1Bust: Although you may actually weigh or measure less right after a sweaty session of Bikram Yoga, the results are short-lived and not an effective way to lose weight. That weight you lost will be back as soon as you replenish the water you lost. As Pop Sugar explains, “during the first few weeks of weight loss due to dieting, a rapid drop in pounds is normal according to the Mayo Clinic.