Unless you’re at that 2-5% of required body fat, chances are you wish you could shred a little more. You’ve heard a bunch of talk about what you need to do, from runners, to Pilates instructors, to Crossfitters. Unfortunately, they usually come from a place of bias. Runners aren’t typically pressing 300lbs, and Crossfitters wouldn’t be caught dead in a half-marathon. My only allegiance is to science (and Batman). So how do you do it?
Alright, so this is the big go-to when people talk about fat-burning. You might have heard that you need to run 20 minutes to start burning fat from burning carbs. This is false, because it’s a little more complicated than that. The biggest lie is that switching from using carbs for energy to fat is a “switch” or something. You’re always burning carbs AND fat, but generally burning a higher percentage of carbs. However, as your carbohydrate stores get low, you switch to using mostly fat for energy. This is called ketosis.
So there are some ways to sort of cheat this a little. Some high-intensity workouts (such as the Ankorr harness bear crawl) can drain your blood sugar super fast. On the other hand, bodybuilders do fasted cardio. This is when you don’t eat for a while before running, cycling, swimming, et cetera. Since you haven’t taken in any carbs in a while, your body uses them up faster and starts eating the fats. Lastly, there’s the tried and true heart rate training, where you maintain a certain level of beats per minute (different for every individual) for a length of time.
This is the Crossfit thing that probably got brought up. It’s similar to, but should not be confused with the Paleo diet. Both remove a majority of carbs from your diet, but Paleo attempts to replicate what our ancestors ate (and it doesn’t do that very well, see Daniel Leiberman’s “The Story of the Human Body”), whereas the regular ketogenic diet is concerned with the three macronutrients (protein, fat, carbohydrate). Ketogenic dieting is kind of like long-form fasted cardio. You’re taking in far less carbohydrates than normal, so you burn through them faster and therefore dipping into your fats sooner. There’s a bit more to it, but that’s the gist.
Here’s what you need to do to lose weight: Expend more calories than you take in. That’s it. Essentially every top-level athlete takes in an ungodly amount of carbs. Even for the layman, they’re great fuel a few hours before a big workout. The trick in terms of diet is to find something that is sustainable for your own life. If you don’t want to change your diet so much, you have one option: Train. Fucking. Hard.
Staying ketogenic or any other extreme nutritional regimen can be very difficult, especially at first, and once you’re off of it, the weight can come back quickly. So keep to something sustainable. Health is not a fad or a phase. It’s a lifestyle.