One of the most heated debates I see fitness professionals, bloggers, and anyone who exercises get into is over which is better - eating before or after your morning workout. I've read dozens of articles on the topic (literally) and I'm going to try to present the evidence to you in an unbiased, scientifically based manner so you can decide for yourselves. I'll also talk about my experiences as I've done it both ways, and see benefits for each side.
Eating Before Working Out
- According to WebMD when you first wake up your glucose is at fasting levels. Trying to work out on an empty stomach may cause your body to break down amino acids from your muscles to use for energy. By eating something your body will instead pull energy from your fat stores.
- The Huffington Post said something similar, but added that you can start to fuel for a morning workout the night before. They also suggested that, if you didn't eat late at night the evening before, having something as simple as fruit juice will help ensure your body doesn't start breaking down muscle for energy.
- The New York Times discusses an experiment that found that 10% of the calories burned by cyclists who exercised on an empty stomach came from muscle. In a separate study, women who ate 45 grams of carbs before their workout ate less the rest of the day. Double win!
- Based on how much time you have before you workout FitSugar has some great tips on what to eat before you workout.
Personal experience: For years my morning routine was: Eat oatmeal, read news/blogs as it digested, then workout about an hour later. It was nice to gradually wake-up and ease into working out. In a perfect world where I had unlimited time in the morning I'd likely stick to this routine.
Working Out on an Empty Stomach
- About.com has an article which states your body will usually have enough glycogen stored up to fuel 90 minutes of high intensity activities so it's not necessary to eat before you run unless you feel hungry.
- Bodybuilding.com argues that fasted cardio may help deplete fat stores quicker than working out post-eating, but if your focus is building strength it's best to eat first.
- This FitSugar article on the dangers of working out on an empty stomach has some great information in the comments section. Most commenters advocated it was okay to workout before eating.
Personal experience: ever since I quit waking up at 1 a.m. every night to take my thyroid medication I've been working out on an empty stomach. I take my meds as soon as I get up and have to wait an hour before working out. Since I'm in a rush to get to work on time I have to workout before I eat breakfast. At first I was terrified. I thought I'd feel weak, dizzy and my workouts would be less effective since I'd have less energy. Wrong! While it's harder for me to find the motivation to actually go straight to working out after I wake up I feel running is easier on an empty stomach. Now when I eat breakfast before I run I feel like I'm running in slow motion! I definitely can't workout for more than an hour if I haven't had anything to eat, but I don't think my performance has suffered at all.
If you tend to eat a snack late at night, and are doing 60 minutes or less of moderate intensity exercise, I think it's okay to workout before breakfast. If your focus is building muscle, or it's been more than 12 hours since you ate last, it's probably best that you eat something first (carbohydrate based) to give you the energy you need and promote muscle gain, not loss. I don't think either way will make you lose fat any quicker, and chances are you will have more energy to workout longer and harder (therefore burning more calories) if you eat first.
Do you prefer to eat before, or after, you workout? Any other Fit Debate you'd like to see me discuss?