Challenge Your Muscles: How Muscle Building Works
Many people start strength training because they want to build muscle. That’s a great goal – building muscle can help you look and feel great. It improves your metabolism, self-esteem, and overall mental and physical health.
Unfortunately, a lot of people don’t know how to train to build muscle, and they’re met with nonsense and misinformation when they try to learn.
To understand what you need to do in the gym, you need to know a little about what happens in your muscles when you lift weights.
You may have heard that muscles grow because when you lift weights you cause tiny micro-tears in your muscles, and when your body heals those tears your muscles get bigger and stronger.
I’ve heard a lot of personal trainers explain muscle growth to their clients this way. Is it simple and easy to understand? Yes. Is it true? Not really.
The reality is much more complicated. This simple explanation leaves out something really important – that you need to challenge yourself with the weights you’re lifting in order to get your muscles to grow. Just lifting any weight isn’t going to do it.
Maybe this is why so many people make the most common mistake I see in the gym: lifting weights that are clearly too light for them, or stopping their sets when they obviously have a lot more in the tank.
Unfortunately, those tiny dumbbells won’t do much for you if your goal is to get stronger and more defined.
To get your muscles to grow you need to stimulate muscle growth. To do that, you have to do one of two things: lift heavy weights, or lift light or medium weights close to muscle failure. Let me explain why.
***Before I start, I want to make something really clear. When I talk about lifting heavy weights, I mean weights that are challenging for you and that you can do safely and with good form. You should never lift a weight that you can't handle. If you're a beginner or if you have a history of injury or pain, you should check with your doctor before starting an exercise program. You should also start with lighter weights and slowly work your way up to heavier ones once you learn good form, and it's always a good idea to consult with a personal trainer to make sure you're doing your exercises properly.
How Muscles Work
Each muscle is made of many muscle fibers, which work together when your muscle contracts. You’ve probably seen muscle fibers if you’ve ever eaten meat that’s been slow-cooked and is so tender you can pull it apart with your fork. Those strands that you pull apart are the muscle fibers.
When your muscle contracts, not all the fibers in that muscle are necessarily working. In fact, when you lift something, your brain directs exactly the right number of muscle fibers to contract within that muscle to be able to move the weight; no more, no less.
Your muscles work that way because it’s very efficient. It takes energy to contract each muscle fiber. Contracting more fibers than you need is a waste of energy, and our bodies really don’t like to waste energy. On the other hand, if not enough fibers are working, your muscles won’t contract hard enough to lift the weight.
Not all muscle fibers inside a single muscle are the same. Some are bigger and stronger than others.
When your brain tells your muscle to contract, it activates the muscle fibers in order of their size. The smallest (and weakest) ones are activated first, then the bigger ones, then the biggest. This is called Henneman’s Size Principle.
How Lifting Weights Signals Your Muscles To Grow
To explain how muscle growth works in a way that’s (hopefully) easy to understand, I’m going to use a simplified example.
Let’s pretend there are just three groups of muscle fibers in a muscle. I’m going to assign each one a color to make this easier to follow:
The fibers in the orange group are the smallest and weakest.
The blue group fibers are medium size and strength.
The green group are the biggest and strongest.
When you lift a pretty light weight, your brain tells only the orange group to work, because those fibers are strong enough to lift that light weight.
If you pick up a slightly heavier weight, the orange group needs the blue group’s help, so both groups are activated.
If you lift a really heavy weight, all the groups, including the green group, are activated to lift that weight.
Here’s the important part: only when the green group is activated (the biggest and strongest muscle fibers) does the muscle growth process start.
Think of it as if those big strong muscle fibers have a little alarm in them that goes off when they’re activated, which tells the alarm monitoring company (your brain) to start the growth process. Then (as long as you’re getting enough sleep and eating well), your muscles will get bigger and stronger.
If you only ever use the smaller orange and blue muscle fibers, you won’t get muscle growth because those fibers don’t have growth alarms.
So, how do you make sure you activate the green muscle fibers to stimulate growth? There are two ways – lift heavy weights, and/or lift medium or light weights close to failure. Let’s start with lifting light weights close to failure.
How To Get Stronger, More Defined Muscles By Lifting Light Weights Close to Failure
Muscle failure means that on your last repetition, you try as hard as you possibly can to move the weight, and it just won’t budge. On a scale of 1-10, that would be a 10 out of 10 effort.
Going to full muscle failure is probably not necessary, but you should be getting within 2 or 3 reps of failure. That would be about an 8 or 9 out of 10 on the effort scale.
If you want to stimulate muscle growth this way, start with a light or moderate weight and keep doing reps until you get close to failure.
Since the weight isn’t that heavy, the orange group (the smallest fibers) can handle it on their own at the beginning of your set. But as you keep doing repetitions, the orange group starts to get tired, and soon they need to call in the blue group for help. A few reps later the blue group is also tired, so the green group comes in to help finish off the last few reps.
Since the green group got involved, the growth alarms were set off and you should be on your way to bigger and stronger muscles. If you stopped early, though, at the point where you could still have done several more repetitions, the green group would not have been activated and you wouldn’t have gotten those growth signals.
How To Get Stronger, More Defined Muscle By Lifting Heavy Weights
The other way to signal for muscle growth is to lift heavy weights. When you lift something very heavy, your brain tells all of the muscle fibers to activate from the beginning of the set, because you need them all to be able to lift the weight even just a few times.
That means the green group gets activated right away and the growth alarms go off. Because the green group is already activated, you don’t need to get as close to muscle failure in this situation, you could stop at about a 6 or 7 on the effort scale and still get the benefits of heavy weights.
By “heavy”, I mean a weight that you can’t lift more than about 5 or 6 times with good form.
Which Method Should You Choose?
The answer largely depends on your training experience and your preference. You should spend the first month or two of your strength training journey just getting used to how to do each exercise and getting comfortable lifting weights at all.
When you haven’t lifted weights before, you will get stronger in the first few weeks just by lifting anything, as long as you do it consistently. It’s pretty amazing.
Once you’re comfortable with how to do your exercises and you’ve been lifting consistently for at least a few months, I recommend starting with the “lift lighter weights close to failure” method. Do that for a few months, then slowly start to increase the weights and decrease the reps until you’re lifting heavy for 4-6 reps in each set.
Remember that good form is key. Never lift more than you can handle, and if you can’t maintain good form during your exercise, the weight is too heavy for you.
Once you’ve tried both lifting to failure and lifting heavy for a while, you can decide what works best for you.
You might enjoy one type of lifting more than the other. Personally, I prefer to lift heavy weights. Lifting a heavy weight makes me feel strong and confident, and I enjoy my heavy sessions and feel energetic afterwards.
I find lifting close to failure much less enjoyable. Sometimes I mix it up and do my first few sets of an exercise heavy, then do the last set lighter and close to failure, just to make sure I’m getting the benefits of both methods.
After trying both methods for a few months, you’ll also have a good idea of what your body responds best to. Several studies have found that some people do better with certain rep ranges than others.
Experiment with different rep ranges and lifting methods, and see what happens. If you don’t like the method you’re doing and don’t feel like it’s working for you, try something else. As long as you’re lifting weights consistently and stimulating those big muscle fibers, you’re doing it right!
The Takeaway Message
The main thing I hope you learn from this article is that building muscle and gaining strength takes effort. You really need to challenge your muscles when you exercise.
Learning to recognize when a weight is heavy enough and building the ability to push yourself during your workouts are important skills of strength training, but they take time to develop.
Start slowly, work at it persistently, be patient, and you will achieve your goals!
If you need help, contact me!
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