When you exercise relative to meals often matters more for reflux than what type of exercise you're doing, which makes timing one of the easiest variables to adjust without giving up a workout routine.
The general guideline
Waiting two to three hours after a substantial meal before exercising gives the stomach time to empty significantly, reducing the volume and pressure available to reflux during movement. A smaller, easily digestible snack closer to workout time (thirty to sixty minutes before) is usually much better tolerated than a full meal.
Morning workouts on an empty stomach
Exercising first thing in the morning before eating avoids the full-stomach problem entirely for many people, though some find that a truly empty stomach causes its own discomfort — in that case, a very small, bland snack (like a few crackers) shortly before exercising is a reasonable middle ground.
Timing around specific workout types
Higher-impact or core-focused workouts benefit more from strict timing relative to meals than a gentle walk does, since the mechanical jostling or abdominal compression in more intense exercise is what tends to trigger symptoms, independent of general fitness level.
