How long before a workout should I eat to get the maximum benefit?
Jason Reff, by email

You should eat a main meal around three hours before a cardiovascular session. This should be a high-carbohydrate, low-fat meal, so it could include pasta, rice, bread or potatoes. This amount of time allows for digestion, assimilation and absorption of the carbohydrate, which will be stored as glycogen in the liver and spare muscle glycogen.

Around 20 minutes before you start your workout, take on a glucose drink or a fast-acting carb snack, which can help top up blood sugar levels. Before a weights workout, you should have a snack that’s high in easy-to-digest protein, such as a glass of milk. This will help maximise muscle growth from your workout.