I'm 14 years old, 5'3.5'' and 135 lbs. i was 131 lbs on monday.
i'm a synchronised swimmer,
and for the past three days we have had four hour practices, i've been eating about 1500 calories a day, which is only a bit more than what i usually eat, which is about 1300.
then we run for a half hour in the morning, we do an out of water workout (crunches, situps, pushups, planks) for a half hour, lap swim for two hours (every 12 laps we get a minute and a half to two minutes for a break), and then we work on team lifts, boosts and highlights, and stretch out splits for the last hour of practice.

but i've somehow gained four pounds?!
i couldnt have been gaining muscle, because you can't gain four pounds of muscle that fast, so could it just be my weight fluctuating?!