How long do you have to wait after eating before you swim?

Generally, a lifeguard or swimming instructor will tell you to wait at least 30 minutes to an hour before swimming after eating to avoid cramps.

My Aerobics class instructor says it is always good to take some 30 minutes break before you start work out again and so, maybe 30 minutes rest after eating would be fine

the reason why they say to wait is to avoid cramps because the blood flow is focused around the intestines and digesting the food. a snack thing is like 20-30 min. a small mean 30-40, and like an actual meal like an hr or more.

15 - 20 minutes and you’ll be fine, but if it’s a big meal just take it easy, don’t push yourself to hard, had a real bad experience with that. Went to do a swimming test half an hour after a big meal, half way through the test I hopped out of the pool and ran to the washroom and puked all over the bathroom stall. Not fun. So just take it easy and let your food digest before you do any intense swimming.