What Changes Can I Expect When I Start Lifting Weights?

If you’re a cardio junkie, stepping into the weight room for the first time can be intimidating. But don’t let that hold you back! Weightlifting is the best way to rapidly change your body – better than cardio, or group exercise, or yoga.

But just because you pick up a pair of dumbbells, don’t expect to see muscles popping out of your abs and arms overnight.

Weightlifting causes your body to adapt

Any purposeful exercise, including lifting weights, is a stressor, and our bodies are really good at adapting to stress. There’s a theory called “General Adaptation Syndrome” that explains how stress creates change in your body. First, there’s the alarm phase, then resistance, and finally, exhaustion.
The alarm phase is how your body reacts to a new stimulus (lifting weights for the first time). This new activity sends a new message to your body and kind of freaks it out. This starts a whole cascade of neurological, physiological, metabolic, and cellular adaptations because your body is trying to prepare to face the stress again in the future.
All of these adaptations are GOOD things! This is how weight training changes your body, by forcing it to adapt to new stressors.
In the resistance stage, your body has adapted to the point that it is capable of handling your new weightlifting routine. You may notice that your strength, endurance, or weight loss “plateaus.”
This can be a frustrating part of exercising, but rest assured that it is a natural part of the process. You can avoid such plateaus by constantly progressing your training – using a little more weight each workout, or increasing your sets and reps over time.
The final stage of adaptation, exhaustion, is what happens if you stress your body too much. This is commonly referred to as “overtraining.” It’s actually pretty hard for most people to get into this stage because our bodies send lots of signals (like feeling sore, tired, and unmotivated) to prevent us from pushing too far. You can avoid the exhaustion stage of adaptation by planning rest and recovery days into your training, eating to fuel recovery, drinking enough water to stay hydrated, and sleeping 7-8 hours each night.

What kind of adaptations come from lifting weights?

You neurological system will be the first to adapt to a new weight training routine. Lifting weights is a skill, like learning a new language or how to play an instrument. Your central nervous system will respond to the weightlifting stimulus by “learning” to fire new neuromuscular pathways, contracting and relaxing your muscles, and creating “muscle memory” of the new movements. This is why new exercises might feel awkward at first, but you’ll quickly get the hang of the technique.
Because your central nervous system adapts quickly, your power and strength will improve once you master each exercise. You’ll be able to lift more weight over more sets and reps in the beginning of a weight training program.
The next adaptation will be muscle hypertrophy (growth) – which is what you’re after if you’re lifting weights. Before this scares off the ladies in the weight room, remember that muscle growth is important for looking lean and toned. “Toning up” simply means losing fat while building muscle. By lifting weights, you’ll shift your body composition from fat mass to muscle mass. And the more muscle you have on your body, the faster your metabolism becomes, allowing you to enjoy eating more food without gaining weight. Win, win, right?
Your muscle and fat isn’t the only part of your body that will change. Resistance training also stresses your skeletal system. Yes, lifting weights will make your bones stronger. Forget osteoporosis – lift weights so you can’t break any bones in your older years.
Finally, lifting weights will improve your cardiovascular system, too. That doesn’t mean you can skip out on cardio (unfortunately). But it does mean that weightlifting increases blood flow, strengthens your heart muscle, and helps to lower your resting heart rate.

What does all this adaptation look like in real life?

Let’s start with the down-side to starting a weightlifting program:

You will be sore after your initial workouts. Any new physical activity will cause soreness because your body is forced to move in novel ways, taxing your muscles and creating micro-tears in the muscle tissue. This can be felt as painful soreness the next day, but it’s actually a good thing because your body will respond by repairing the micro-tears and becoming stronger and more resilient as a result.


It will be hard. Learning any new skill is challenging, and weightlifting is no exception. Once you learn proper form and technique, you’ll be able to push yourself to lift heavier weights, and your workouts will still be hard. This is good! The cliche “what doesn’t challenge you, doesn’t change you” is true – your body won’t adapt and grow stronger if your workouts are easy. Embrace the challenge.
You will feel tired and hungry. You will probably feel tired during or after your workout at first. You may feel like you need more sleep than usual. This is because you’re expending more energy than you’re used to, and your body needs extra sleep to recover. Your appetite will likely increase, too. This is your body’s signal that it needs more calories and nutrients to repair your muscles after your workouts. A combination of calories, protein, vitamins, minerals, and sleep will help your body to recover and become stronger.

And now for the up-side of weightlifting:

You will get stronger, quickly at first. Think of this as part of the learning curve. When starting something new, you have to think through each step. It’s mentally labor-intensive. But, as you develop muscle memory for the exercises, you don’t have to think about each movement. You’re able to execute reps with ease. This allows you to focus on increasing the weights you use week to week, which accelerates your strength gains.

Your muscles will grow. Again, not to scare off the ladies. This is a GOOD thing. More muscle means a higher metabolism, which helps you burn calories and body fat without even trying. And more muscle means you will achieve that lean, toned look so many of us step foot into the gym to achieve.
Your body composition will improve. Remember, “toning up” really means losing fat while building muscle. This is also referred to as body recomposition. It won’t show up on the scale, but your clothes will fit better and you’ll look more lean and toned as a result of lifting weights.

If you stick with your weightlifting routine, you’ll start to notice these things:

  • Your workouts won’t seem so hard. You’ll be able to add weight or do more sets and reps with less effort.
  • You’ll actually feel energized after weightlifting session. Even if you were tired beforehand or during the workout.
  • You’ll have more energy for the rest of your day after your weightlifting workout.
  • You will experience better and deeper sleep because weightlifting triggers positive hormonal reactions in your body. 

The negative things we talked about above – feeling tired and more hungry than usual? That hunger you experience and extra calories you consume as a result will be used to rebuild your muscles. This means you will see more tone and definition. And because muscle mass increases your metabolism, you will start to burn fat from your body and “lean out.”
Don’t expect to look like the Hulk after a few weightlifting sessions, though. It takes weeks, months, and even years to add muscle mass. A realistic expectation for new weightlifters is to add 1-2# of muscle per month.
Your new muscle will impact the scale, and this is where a lot of weight training newbies start to freak out. Most people step into the weight room to lose weight and look better. But keep in mind that muscle is more dense than fat mass. This means that 1# of muscle will look “leaner” than 1# of fat – it takes up less space on your body. So while the scale may be going up… your clothes will start to fit better. Stick with it!

Other than benefits to energy, strength, and aesthetics, you’ll probably start to notice a new sense of confidence, both inside the gym and outside. Getting stronger makes us feel more capable of handling everything life throws our way.

In fact, strength is the number one determinant for a long and fulfilling life. Studies have shown that grip strength directly correlates with life expectancy. Weight training will not only help you lose weight, it can help you live longer.

True, weightlifting is HARD work, but it’s worth it. Among the many amazing benefits of weightlifting is increased strength, greater self-confidence, a healthier heart, a longer life, and a better looking body.
If you’re just starting out, remember that it will get easier with practice. You just have to show up at the gym and put in the work, day in, and day out. Your body will adapt. Results will follow.