As recommended by ACSM, it is best to eat a higher carb- low fat meal about 3- 4 hours before exercise. Snacks are usually okay around an hour before exercise as long as large amounts are not eaten at one time. Make sure that you are drinking water with the meal as well. Around 5-7ml/ kg at least 4 hours before vigorous exercise. Make sure to stay fueled and hydrated!
Best of luck,
Each person responds different, but usually if you have a regular meal 2-3 hours before working out should be enough. Intensity, type of training and some medical factors (for example if you are diabetic) could also play a part. Definitely wait 3-4 hours after a meal if you are going to train in the water.
I have a slightly different answer as the others. Since you don’t state that you’ll be eating a meal, having a light snack consisting of a carb and protein an hour prior to working out will help to fuel a more intensive workout. Especially if working out in the morning, having something light to eat prior to a workout is a must as you’ve been fasting while sleeping.
However if you’ve just eaten a large meal, 2-3 hours is the ideal to aid in digestion.