5 Training Mistakes Preventing You from Building Muscle and How to Fix Them

Building muscle isn’t just about lifting weights—it’s about optimizing your training to get the best results. Many people unknowingly make common mistakes that hinder their progress. In this post, I’ll walk you through five critical training mistakes that could be preventing you from building muscle effectively and share practical tips to help you make the most of your workouts.

Mistake 1: Repeating the Same Number of Reps Across All Sets

One of the most common mistakes, especially among beginners, is doing the same number of reps for multiple sets with the same weight. For instance, doing three sets of eight reps with the same weight might seem like a solid strategy, but it often means you're not pushing yourself hard enough. If you can do 10 reps in your first set but still do 10 reps in your third set, you're leaving potential gains on the table.

To maximize muscle growth, your reps should naturally decrease from set to set. Start with a weight that allows you to push close to failure in your first set. As a result, you should only be able to do a few less reps in the following sets due to fatigue. Again, if you perform the same number of reps across multiple sets, you’re likely leaving reps in the tank on your earlier sets and thus, not making the best gains possible. Focus on training with high intensity. For example, if you perform 10 reps in your first set, you should only be able to do 8-9 reps in the second, and 7-8 reps in the third as a result of pushing your body near its limits. This approach ensures you're challenging your muscles adequately, promoting better muscle growth.

Mistake 2: Not Resting Enough Between Sets

Another mistake is resting too little between sets. If you’re only resting for a minute or two, you’re not giving your muscles enough time to recover, which can limit your ability to lift heavier in subsequent sets. 

I’ve often heard people say that “resting long is boring” and that “they feel ready to go for another set after resting one minute.” If you feel like you’re ready to go for another set after 60 seconds of rest, you’re simply not pushing yourself hard enough. Your body should be begging you for longer rest.

How long should you rest between sets then?

For big compound exercises like squats and deadlifts, rest at least 3-5 minutes. This allows for better performance and muscle recovery. If you feel like this is too long and you’re going to be in the gym forever, simply cut the number of sets you’re doing. You’ll get more out of your training if you perform a couple of very intense sets with plenty of rest versus doing the opposite.

On smaller isolation based movements, like a bicep curl or leg extension, resting 2-3 minutes should be plenty since these types of exercises are not nearly as fatiguing as compound movements.

Mistake 3: Avoiding Machines in Favor of Only Free Weights

While free weights are excellent for building muscle, relying solely on them may not be the best strategy to build muscle optimally. Big, free weight compound movements like barbell squats, barbell bench presses, and deadlifts are extremely difficult and fatiguing movements. If all of your training is centered around these types of movements it can lead to excessive fatigue and limit your workout’s effectiveness. 

I recommend opting for a combination of machines and free weights. Machines can provide the necessary stability and support, allowing you to focus more on muscle engagement, especially when you’re already fatigued. Make sure to incorporate both free weights and machines into your routine to optimize muscle growth.

As a rule of thumb, I tend to start most of my workouts with a free weight compound movement and then transition toward a machine based compound movement as a secondary exercise for whichever muscle group I’m working on that day, and I recommend you do the same.

Mistake 4: Not Using a Full Range of Motion

A common mistake among both beginners and experienced lifters is not utilizing a full range of motion in their exercises. When you don't move through the full range of motion, you’re limiting the muscle activation and engagement that’s necessary for optimal growth. Partial reps might feel easier or allow you to lift heavier weights, but they don’t fully challenge the muscles throughout their entire length. For example, when performing a squat, many people stop at parallel or even higher, missing out on the opportunity to fully engage the glutes and hamstrings. Similarly, in exercises like the bench press or shoulder press, not lowering the weight all the way down to the chest or not locking out at the top can prevent the full activation of the muscles involved.

To maximize muscle growth and strength gains, you should strive to use the full range of motion for every exercise. This means moving through the entire arc of the movement, from full stretch to full contraction. For example, when squatting, go as low as you can comfortably manage to ensure full engagement of your glutes and hamstrings. If you're performing a bicep curl, make sure to lower the weight until your arm is fully extended and then curl it up to the point where your bicep is fully contracted. Using a full range of motion not only helps in building muscle effectively but also improves flexibility and joint health over time. It’s essential to prioritize quality over quantity—lower the weight if needed, but ensure that every rep is performed correctly.

Mistake 5: Changing Exercises Too Frequently

Many people make the mistake of constantly switching up their exercises, thinking that this variability will shock the muscles into growth. While it’s true that varying your routine can be beneficial to prevent plateaus, changing exercises too frequently can actually be counterproductive. The body needs time to adapt to specific movements, and by frequently changing your exercises, you’re not giving it a chance to master the technique and progressively overload the muscles. Mastery of an exercise allows for better neuromuscular coordination, which leads to more effective muscle activation and growth.

To see meaningful progress, it’s important to stick with a consistent set of exercises for a period of time—typically around 4-8 weeks—before making any significant changes. This timeframe allows your body to adapt to the movement patterns, improve your form, and progressively increase the weight lifted. Once you've reached a plateau or mastered a particular set of exercises, then it’s time to consider switching things up. You can change the type of exercise, the order in which you perform them, or the number of sets and reps. The key is to maintain consistency long enough to reap the benefits of adaptation while also knowing when to introduce variety to prevent staleness and continued growth.

Conclusion

By avoiding these common mistakes, you can make your workouts more effective and see better muscle growth. Remember, consistency and proper technique are key. If you need further guidance or personalized training, consider reaching out to a professional coach who can help you optimize your workouts and achieve your fitness goals.