As a trainer, I find myself reminding my clients how important it is to fuel their bodies for their workouts. This doesn’t necessarily mean you should eat an entire meal before you hit the gym, but it is important to make sure you eat something. I know that sometimes I hear “I don’t like eating before I work out” or (especially morning workouts), I’ll hear “I don’t like to eat breakfast.”
What you need to keep in mind is: Whether your goal is to build strength, increase endurance, or lose weight, you need to make sure you’re giving your body the fuel it needs. Here are the top signs you're not eating enough before exercising.
1. You're dizzy, lightheaded, or lethargic. If you’re doing a moderate to high intensity workout without properly fueling your body, your blood sugar can drop and leave you feeling dizzy or faint. If you feel lightheaded, you need to stop exercising immediately. A quick carbohydrate or sugar might help (like a piece of fruit or some fruit juice). Dizziness is also a symptom of dehydration, so drink some water too.
(*Even though it’s not as common, keep in mind that there are some health conditions that can make you lightheaded or dizzy during a workout, like heart problems or even asthma. If you feel this way fairly often – even with proper fueling and hydration – you might want to check in with your physician.)
2. You're nauseous. If you're feeling nauseous, this may be more of an indication of dehydration. Think about how much fluid and electrolytes you've had for the day. It could be that you forgot to drink enough water, or maybe you haven’t had enough salt. Being low on electrolytes (like salt) can result in nausea, among other symptoms like muscle cramps and confusion. Sodium is an important electrolyte that's essential for regulating nerve and muscle function in our bodies. When we don't have enough (usually because we've lost it through sweat), our cells can't send signals properly, and we experience symptoms like cramping, dizziness, headaches, and nausea.
3. You're not performing as well as you know you can. If you’re low on fuel, you might feel like your energy is just gone. Poof! If you feel like you’re not working out as hard as you normally do, you might be low on fuel.
4. You're injuring yourself, or even passing out. This is dangerous. If you are under-fueling and not intaking enough calories or carbohydrates, you can run the risk of low blood sugar (which can lead to passing out). When you are not properly fueled, you can put yourself at risk for injury.
5. You're not seeing results. Whatever your goals may be, your ultimate success may be impacted (negatively) if you’re not eating enough. When you don’t eat enough to fuel your body, your body may start using your muscle as fuel. That’s not good. Also, depriving your body of the fuel it needs may actually mess with your metabolism and make it harder to lose weight. Believe it or not, sometimes increasing calories is what helps people end up losing weight.
Here are some basic guidelines:
- You can either eat a normal-sized meal about 2 – 3 hours before a workout or have a small snack 30 to 60 minutes before.
- Whatever you eat, make sure to include carbohydrates and protein with some fat and fiber. (If you're eating less than an hour before a workout, limit the amount of fat and fiber you eat because large amounts can slow down digestion and cause stomach cramps or nausea.
- If you’re opting for a snack, think pretzels and hummus, a banana or slice of toast with some nut butter, or a hard-boiled egg and a slice of toast.
- Make sure you're hydrated.
Keep in mind that it’s important to make sure you're fueling and hydrating throughout the day so your body can repair, recover, and get stronger from your previous workout.