The decision on whether to exercise in a fasted (i.e. at least 8 hours after your last meal/snack) or fed state depends on your goals as well as the intensity and duration of your workout.
If you are wanting to increase your stamina (Schabort et al 1999), enhance your performance (Chyssanthopoulos et al 2002) or your workout is high intensity or longer than an hour, you would ideally eat a meal 3-4 hours prior to exercise, followed by a small snack 1-2 hours before your workout.
However, if your workout is low intensity or no more than an hour in duration, you can get away with exercising in a fasted state (i.e. first thing in the morning before eating breakfast).
What if your primary goal is to lose weight? Although a greater proportion of fat rather than carbohydrate will be used as a fuel source when exercising in a fasted state (Bock et al 2008), you may find that you are able to trainer harder (and therefore burn a greater amount of energy overall) if you include a small snack prior to your workout. A small pre-workout snack may also prevent you from feeling ravenous and therefore tempted to overeat after your gym session.
If you decide to eat something before exercising, opting for a small carbohydrate rich snack about an hour before exercise would be the best choice.
The aim is to choose something that is easily digested to minimise the risk of gastrointestinal discomfort during your training session. Typically this will be a small snack that is lower in fat, protein and fibre as larger meals or foods higher in these macronutrients take longer to digest (Hawley and Burke 1997).
For example, try one of the following:
- piece of fruit (e.g. 1 medium banana)
- small milk-based smoothie (e.g. blend ½ cup milk with ½ medium banana, ½ cup frozen berries or other fruit of your choice)
- small tub (150-200g) plain yoghurt
- muesli/cereal bar
Hydration is also an important aspect of pre-workout nutrition as dehydration has been shown to negatively impact upon performance (Goulet 2012 and Davis et al 2015).
Ensure you are well hydrated before your workout and continue to hydrate with small sips during training. Water is best for low intensity and short duration training (Kenefick & Cheuvront 2012).
Of course, liquid meals/snacks (e.g. smoothies) will contribute to your fluid intake, as will electrolyte drinks (e.g. Gatorade) if you have chosen to include these in your nutrition plan.
What About Pre-workout Supplements?
More to come on this topic in another post soon.
Long story short, you’d be better off trying a cup of coffee instead as the mostly commonly used active ingredient in the majority of pre-workout supplements is caffeine which has some good evidence to support its performance enhancing action (Goldstein et al 2010).