There’s been a lot of talk about reducing and/or eliminating carbohydrates from the diet, the metabolic state known as ketosis, in order to reduce the body’s fat stores and lean out. As with so many programs for cutting, there is a right and a wrong way to do this. Let me explain how this can go terribly wrong.
Ideally, one would desire to continue strength training while in the state of ketosis in order to maintain muscle weight and size. The idea here would be to keep the muscles full while reducing the amount of fat in and around them (cutting). However, strength training is what is known as an anaerobic activity. This simply means that the muscles are using a system of energy that takes place in an environment where there is no oxygen being used. Bear with me for a minute. There are two types of anaerobic energy systems: 1) the high-energy phosphates, which are ATP (adenosine triphosphate) and CP (creatine phosphate), and 2) anaerobic glycosis. The high-energy phosphates are stored within the muscle cells in very small amounts. Anaerobic glycosis uses glucose (and glycogen) only as fuel in the absence of oxygen, or actually more specifically, when ATP is needed faster than the aerobic metabolism can provide. The by-product of this rapid glucose breakdown is lactic acid, the chemical that was once blamed for making your muscles fatigue and also plays a part in delayed onset muscle soreness. It takes about 30 seconds to exhaust the ATP-CP stores and then the anaerobic glycosis kicks in.
I’ve explained all of that to tell you this: being in ketosis leaves your muscles (and liver) devoid of glycogen. The simple result of this depletion is that your muscle will feel weak and ultimately fatigue prematurely. Not exactly what you want to happen while you’re in the middle of a big bench press.
As you know, when you are strength training, your muscles are being broken down (on a cellular level). After you stop working out, your body will begin to repair the broken-down muscles utilizing a process known as protein synthesis. As with any injury or damage to the body, when the body repairs itself, it always repairs it stronger. It is this very process that allow a lifter to gain strength and size over time with his (or her) workouts. During protein synthesis, the muscle cells require amino acids for repair, and in fairly large amounts. When the body is in ketosis, it is burning ketones and amino acids for energy. The amino acids you use up during your workouts will ultimately not be available for cell repair afterwards. The result? Your muscles will not be able to recover and repair properly and at the very least, you won’t grow or get stronger. At the worst, you will burn out and actually begin to get smaller and weaker (overtraining). Again, not a desirable result.
So, how do all of these bodybuilders who go low-carb to cut maintain their muscles? Honestly, some don’t. But if you do it right, you can. And here’s how. It’s called carb cycling or cyclical ketogenic diet (CKD).
The body will generally not go into ketosis until after somewhere between three to five days of carb restriction. This is handy knowledge, because this means we can restrict carbs for three to five days, workout hard and not suffer any of the negative side-effects of ketosis. The trick would be to get some carbs into the body before it hits the state of ketosis. Usually what works is three to five days of severe carb restriction followed by one or two days of carb consumption, followed by three to five days of carb restriction, etc. Simple, right? Not really. The time after which the body enters ketosis is a little different for everyone. Yes, it’ generally three to five days, but sometimes it’s more. It can actually occur after up to seven days for some lifters. And exactly WHEN it’s going to hit within that range, will require a lot of experimentation.
My suggestion: if you’re really looking to shred, get on a decent strength training workout with minimal cardio, cut your carbs for three days and see how you feel. If you’re feeling like you still have enough energy, give it another day. Keep going with this, a day at a time until you start to notice your energy dropping. Do not wait until you’re completely spent! The moment you notice your energy beginning to dip, it’s time. Hit it with some good complex carbohydrates: yams, sweet potatoes, brown rice, etc. After a day of this, go back to the carb restriction. Watch your energy again. You’ll notice that you may hit the wall a little sooner this time. That’s ok. Go ahead and carb up when you’re ready and repeat the process. Pretty soon you’ll find the rhythm and have it nailed. Then you’ll know exactly what to do. The key here is that if you ever start to feel extremely weak and fatigued, get some carbs, but then go back to the restriction quickly. Keep up this cycling and in time you will be leaner and harder, and still have a lot of the muscle you have worked so hard to build.