This can be a tricky question, depending on the person, and the goals that they have set out for themselves. Different workouts can affect your macro-nutrient burn rate.
I’m not going to give someone who wants to play football the same workouts as a guy that wants to run marathons. Nor will I give the same advice to the 16 year old adolescent trying to “get huge,” and the mom trying to lose her baby weight. Sure, there’ll be some crossover, we all want to get stronger and faster, but each person can have vastly different needs.
For today, my answer is going to focus on weight loss & better body shape, since that seems to be a pretty common goal for most people, and for many of those just starting the Paleo lifestyle.
The great news about those of you who are already on the Paleo train is that you already have the most important piece of the fitness puzzle addressed. Your nutrition. You simply can’t exercise away a bad diet, I wish you could, I really do. Exercise can do some amazing things for you, and for sure makes a difference in your goals, but all the sit-ups in the world won’t fix eating two sleeves of Oreos every night.
Fitness and movement-wise, we’re going to take a little peak under your biological hood, and attempt to give you a better understanding of how the body utilizes and stores calories from different sources, how exercise affects that utilization and storage, and how to make better choices about what you put into your face, so that those choices can reflect how you look & feel! Because in actuality, they already ARE affecting how you look & feel!
Fat Burning or Sugar Burning
First off, there is a time and place for both high intensity, fast type workouts, and for the traditional LSD (Long, Slow Distance) workouts. As we’ll see in the following paragraphs, one is more a sugar burning activity, while the other is more fat burning. Be careful now, traditionally, we’re led to believe that fat-burning is key, but it may turn out that you actually want to burn more sugar in your workout!
Generally speaking, your body runs a lot of it’s daily needs by using fat. It’s a nice dense fuel, and for stuff that doesn’t take big amounts of effort, you’re probably burning fat while you do them. Chances are, you’re burning fat right now, reading this.
Fat is a very dense fuel.
Actually, it has a bit more than twice the caloric punch per gram ingested. One gram of fat has 9 calories of energy stored in it, while carbs have only 4 calories per gram (protein has 4 calories per gram as well). Meaning that for each gram of fat you store, you’ve got a lot of potential energy just sitting there waiting to get tapped into. So, are you tapping into it? We’ll see!
When you wake up in the morning you are essentially in “fat burning mode.” Meaning that you are starting to use your fat stores as energy. That should make logical sense, since you (hopefully) haven’t been eating while you’re sleeping. You’re liver has been slowly dripping out a little feed of sugar into your blood stream to feed your brain, but the rest of the body has been in a nice slow fat burning mode. Actually, as you read this you are probably in fat burning mode as well. Anything that you can sustain longer than several minutes is essentially aerobics, and therefore fat burning. Sitting at your desk reading this incredible article isn’t necessarily a huge tax on your system, neither of us would really consider reading “exercise.” You’re not having the same calorie burn as a walk, or even a light jog, but technically, you are burning fat, just maybe not at a super slow rate.
At 185 lbs, I burn about 140 calories, just sitting here working on this article for an hour. That’s about 15 grams of fat, or about 1/2 an ounce. Not even close enough for a donut. ;)
Most of us have enough fat to walk, quite literally, hundreds of miles. Unlike sitting, walking at a moderate pace takes close to 2 hours to burn off a pound (450 calories) of fat. That’s about 6 miles. If you’ve got 10 pounds to lose, you could theoretically walk it off in just 60 miles! Assuming you’ve not eaten anything during your jaunt, get your shoes on…let’s go!
We can see that fat is a great source of fuel for long, sustained, slower activity. The cool thing, from an evolutionary standpoint, is that our bodies’ capacity for storing fat is basically limitless. We can store as much as we can make.
Then why do we need sugar?
Sugar is a fast fuel for your body.
Fat burns relatively efficiently, yet more slowly, while sugar burns fast and leaves behind a little “smoke” that your cells have to deal with. Feel that burn? Yeah, that’s what I’m talking about! That’s that sweet lactic acid, a side affect of sugar burning up in your muscles, that happens during exercise (not the soreness after, that’s something different). Those faster bursts of energy require fast energy demands, and that means sugar instead of fat. Once the local stored sugar (specifically in this form called glycogen) is gone the body switches over to aerobic mode, or all that lactic acid will lead to that burning feeling that makes you stop, ouchy!
Over your whole body, you can store anywhere from 200-400 grams of sugar in your muscles. This is almost entirely dependent on how much lean muscle you have on your frame. Your liver stores a bit as well (50-100g), but the muscles carry the majority. The ONLY way to store more glycogen (sugar) in your system is to get more muscle mass. Huge bodybuilders can store a LOT, the rest of us have pretty much a set limit on what we can store.
Muscles are stingy buggers and they don’t share with each other very well. That means that if your bicep is all out of sugar and experiencing a total breakdown, your tricep won’t even flinch. Your muscles can’t share sugar with other muscles. What this means is that if we want that stored sugar to move out of the muscle, we have to work THAT muscle!
By extension, once your muscles and body are “full” of sugar, your body will flip a little chemical switch and store that excessive sugar as fat. Fat, as we mentioned above, has no limit to storage.
What type of exercise is right for me?
All this was required so we can understand the basic concept of burning muscle sugar, or burning fat during a workout. If I don’t burn any sugar during my workouts, chances are my muscles are already “full” of sugar, and they can’t store any more. That means that I’ll store excessive carb intake as fat.
What about the fat burning zone?
We’ve all read a lot about staying in the fat burning zone when you workout. It’s somewhere in that 50-70% heart rate range. While it is true that when you’re in this little zone you’re probably burning mostly fat, that may not be the end of it. If you’re eating a completely ketogenic diet, and are totally a fat-adapted machine, then yes, you may be on the right track. For those of us that eat more than 50-100 grams of carbs a day, we have a few more things to consider.
If we spend an entire workout in that fat burning zone, then we haven’t asked our body to burn the sugar out of the local muscle cells.
The easiest way to think about this is in terms of what is “empty” after your workout. If you’re burning primarily sugar for your workouts, then you’ve given yourself a little bit of room to top off the sugar stored in your muscle. However, if you’ve only burned fat, and your not “fat deficient” (is ANYone?), then any sugar you eat will just be stored right back as fat. You also are NOT sugar/glycogen depleted either.
Assuming aerobic, fat-burning activity, if you refuel with carbs, they have nowhere to go. You’re muscles are still “full,” since they haven’t been tapped. So you body will most likely take that sugar and turn it into triglycerides to store as fat. IF you’ve done some higher intensity work, and gotten your muscles to burn through a bit of their sugar stores, then you can have that edible sugar refueling the muscles instead of being transferred and stored as fat. THIS ONLY HAPPENS IF YOU WORK THE MUSLCE, HARD.
Do you follow what’s happening here? If you work your muscles hard, they’ll burn more sugar, and take up sugar if you eat it. If you do more LSD work, then you’re burning fat, and not going through any fast-burning sugar. If you then eat higher carb, those carbs have nowhere to go (the muscles are still full) and will end up as fat down the line.
Aerobic Workout or Long, Slow Distance Workout (LSD)
Work both sides. Spend some time getting into a bit of fat burning, after all it is good to burn some calories, but don’t forget to really work those muscles every so often, say two to three times a week, so you can reap the benefits of having your muscles deplete and replenish your carbs consumption a bit for you.
While most of us are quite familiar with the typical long slower cardio workouts (10k run anyone?), you may need a nod or two for how to get those muscles to burn through some sugar. You can do this a bunch of ways. Of course, we’d love for you to do it with our workouts (they’re kinda designed for that), but any kind of sprint work that you can think of will work for you. Sprint work means, feeling like you want to quit. As in going hard enough that you want to stop, but you don’t. Tabata intervals are great for this (20 seconds of max effort movement, followed by 10 seconds rest for 8 rounds), as is dragging a weighted tire, or pushing a sled…something that you quite literally feel like you HAVE to stop, or your legs, arms, whatever are going to stop working. That’s the gold that we’re looking for, kind of complete breakdown. Oh…then you should also do another set, because I know you cheated and left some “in the tank.”