| Desroko said: Wow. Umm, losing that much weight that quickly is not actually healthy. It's not all water weight, either. You're almost certainly losing muscle mass. |
Just as you cannot lose 4lbs of fat in 4 days, you can't lose 4lbs of muscle in 4 days either. Muscle simply does not atrophy that quickly, even in a zero G environment.
Body weight can fluctuate about 5lbs in a day, given the right circumstances (up to 7 according to Wii Fit), but most of that weight fluctuation is water, and the amount of food traveling through your GI tract.
The easiest way to determine body water % (and water weight) is with a scale that measures body fat % and water % like a Tanita.
But even if you did a genuine max workout (like run a marathon) you can still calculate the amount of energy reserves you burned off and then figure out how much of the weight you lost during such a workout was due to water loss, even without such a scale.
It takes 3600 calories worth of activity to burn off 1lb of fat. You have to run at a pretty decent pace to even burn off 1000 calories per hour to give you an idea of how much activity it would take to burn off 4lbs of straight fat.
Increased metabolism due to sustained increases in activity levels however, will continue to burn more energy during sedentary periods, particularly with increased muscle mass. But this is not an effect you would expect to see after just a dozen or so moderate workouts.
