Eating the wrong thing before the gym can set you up for a rough workout. Ben shared a cautionary tale about mac and cheese here for anyone lacking the first-hand experience. Of course, everyone’s digestive system is different. It takes some experimenting to figure out what works best for fueling your workout, but we’re all fueled by food and we can break that down to pre-workout and post-workout fuel.
Before a workout
Like I mentioned above, experimenting is key, but in general aim for a small meal about 30 to 90 minutes before exercise. To start, pick something that’s high in carbohydrates and lower in fat, protein and fibre. Try a piece of fruit or a small bowl of homemade oatmeal to start. Also, keep in mind the type and length of workout you’re doing. I’ll skip coffee if I’m about to do burpees in bootcamp, but I’ll happily caffeinate before a hike (not to mention bring an extra piece of fruit to re-fuel).
You can’t function without water. When you’re hydrated, your heart actually pumps blood more easily. On its own, that’s a pretty good reason to drink up, but add in exercise and it’s even more important. Every pound of sweat you lose, equals one pint of water that your body needs to have replenished. Going into a workout you want to be hydrated, so drink water throughout the day. It’s not a bad idea to track your water intake occasionally too. You can also add foods with high water content–like peaches, grapefruit or watermelon–to your diet. The amount of water needed is different for everyone. The easiest way to keep an eye on your hydration is to keep an eye on the colour of your urine: pale and clear is the goal. Post-workout you’ll need to rehydrate while replacing any electrolytes lost through sweating. If you weigh yourself before and after a workout the difference will be the amount of water you have lost (not fat, unfortunately). 2.2 lbs lost equals 1 litre of water lost. Adding a pinch of salt and a squeeze of lemon to that water is an easy and cost effective way to replace your electrolytes.
After a workout
In addition to hydrating after a workout, you’ll likely want to refuel. There’s evidence that the body can better absorb protein and carbohydrates after working out. That’s why protein–especially in the form of quick-to-eat shakes and bars–is commonly pushed as a post-workout snack. In reality, the additional benefits here are small enough, that the average gym-goer is better off focussing on refueling beyond it. Try to think about your refuel meal in the context of the calories and macronutrients you’ve already eaten that day. It’s easy to overindulge–or justify the drive-thru–when you’re ravenous from squat jumps. But resist the temptation! Who knows? Maybe those squat jumps will feel easier tomorrow.