Exercise is merely a stimulus for change. The purpose of exercise is to induce stress on the body (e.g. mechanical stress, metabolic stress, nervous system stimulation). It’s not just to burn calories or to get our hearts pumping. Exercise is a tool we need in order to force our bodies to change.

Our physiological readiness to withstand the stress of exercise and the way we nourish our bodies between exercise sessions are what truly dictate our response. In other words, our bodies need to be challenged, but also need to recover if we want to see positive changes.

Perhaps this is why many people who exercise but don’t pay much attention to nourishment (or have altered physiology) don’t see jaw-dropping or even noticeable results.

Your pre- and post-exercise nutrition strategies are driven largely by the frequency, intensity, duration, and types of training you choose to do. These choices not only make or break your workout performance, but also your recovery between sessions.

Article ShortcutsHydrate!Nourish for damage control.Top off with high-octane fuel.Replenish nutrients (and fuel).Non-food nourishment is also a must.

One thing that holds true regardless of these variables is whether you choose solid foods or liquids for the best gastrointestinal tolerance. The table below can help you plan those choices. (Keep in mind tolerance will vary among individuals.)

Hydrate!

Before you work out strenuously, be sure you're well-hydrated, since hypo-hydration is enough to significantly elevate cortisol during and after training — which is catabolic, meaning it breaks down muscle tissue. Lack of proper hydration is also shown to reduce the post-resistance training testosterone surge, and also alters carbohydrate and fat metabolism for the worse.

Slight dehydration (~3 percent body mass loss) has also been shown to decrease maximal strength and repetitions, increase heart rate and perceived exertion, and hinders heart-rate recovery.

Being hydrated is more complex than simply

drinking enough water, but that can only be determined through comprehensive

blood testing and urinalysis. While your water tracker in your food journal

will help you tally up the ounces you drink, your physiological markers of

hydration will be the best indicators of cellular hydration.

Nourish for damage control.

Since exercise can be quite catabolic — literally breaking down some healthy tissue to stimulate repair and building of new tissue — it’s smart to anticipate such damage and prepare for it ahead of time.

Resistance training is known to damage muscle

fibers. If done correctly, the microscopic tears created during the session can

take days to be repaired.

Strenuous metabolic training (higher-intensity cardio) uses up available fuels so quickly that our bodies release hormones (called catecholamines and glucocorticoids, such as epinephrine/norepinephrine and cortisol) to break down healthy tissue to make glucose.

To minimize the potential damage, you need to enter strenuous training sessions with plenty of available amino acids. Amino acids are the individual components of all proteins — the proteins we eat and the proteins we build (like muscle tissue).

We need relatively consistent intake of

protein-rich foods to maintain good protein status. 

For protein needs, within two to three hours of starting a tough training session, be sure to eat at least a palm-size portion of meat, fish, poultry, or eggs to supply your body with a rich pool of amino acids.