Is it normal for the muscles to increase in size as a result resistance training?

Hypertrophy training and strength training are two potential focuses of resistance training. Focusing on one area does not mean you will not experience gains in the other.

Rather, modifying your workout design may help you to gain muscle size or strength faster than doing general resistance training or unfocused resistance training.

With enough time, you will notice changes in both muscle hypertrophy and strength no matter your focus.

Keep reading for a more detailed breakdown of resistance training, the similarities and differences between hypertrophy and strength training, and general information on what you need to change to accomplish both.

Resistance training is a form of exercise that uses external resistance to increase strength, endurance, and hypertrophy. It is a broad term that includes:

• bodyweight exercises, like push-ups and pull-ups
• weightlifting, such as kettlebells, barbells, bands, and other gym equipment

Resistance training helps your muscles adapt or change. In addition to strength and hypertrophy adaptations, resistance training can help with:

• muscular endurance: ability to produce and maintain force for a long period of time
• power: ability to produce the most amount of force in the shortest period of time, also known as explosive power
• stability: helps with range of motion and stability around the joints

Acute training variables

To achieve different results, you need to make modifications to your resistance program by making changes to what is known as the acute training variables.

The National Academy of Sports Medicine (NASM) defines acute training variables as the most fundamental component of any training program. The variables determine the amount of stress you put on your body, which will eventually lead to the adaptations you want to achieve in your muscles.

The acute training variables include:

• repetitions
• sets
• training intensity
• training volume
• repetition tempo
• rest interval
• exercise selection
• exercise order
• training duration
• training frequency

In other words, making changes to any of these factors, when done correctly, can help your body adapt the way you like.

Starting out: strength or size?

NASM warns that you should not jump straight to training for hypertrophy. You need to first develop a strong foundation and move into a more advanced phase once you have a stable base.

Also, when first starting out, you may not be likely to see major gains in size right away. According to a 2018 review, when you first start out, you will gain strength rapidly at first, along with neural adaptations. After the initial strength gains, you will likely start to see some slow, but likely steady gains in size.

Training for hypertrophy and training for strength are interconnected.

Hypertrophy training

Training for hypertrophy means you are looking to increase the physical size of your muscles. It can take several months for you to notice any results.

Bodybuilders focus on resistance training for hypertrophy, but you may be interested in this form of training to change the appearance of your own muscles.

Strength training

Training for strength involves training your nervous system to use as many muscle fibers as needed to overcome an external force. It is a neuromuscular adaptation, meaning your nervous system learns to communicate better with your muscles to produce movement and create force.

Strength training plays a vital role in most sports training as well as everyday life. It also plays an important role in keeping you healthy.

How to choose

They interconnect because they often occur at the same time. When you train for hypertrophy, the increased muscular size can increase your strength. When you train for strength, the ability to perform tasks for longer periods can lead to hypertrophy.

However, you can adjust the acute training variables to focus on either hypertrophy or strength training. According to NASM, the 5 key variables you need to consider when picking between focusing on hypertrophy or strength are:

• intensity
• reps
• rest period
• sets
• exercise selection

Intensity

Muscle adaptations require muscles to become damaged, stressed, and fatigued. Intensity affects how quickly your muscles reach fatigue.

To be effective, the intensity you select needs to be enough to generate stress while allowing you to do enough reps to reach fatigue.

Reps

Reps refer to the number of times you perform the action of a particular exercise. For example, you may do 10 reps of squats while at the gym as part of your routine.

Reps and intensity have an inverse relationship: as your intensity increases, you need to decrease the number of reps you do.

Strength often improves at higher levels of intensity, meaning that you will typically gain the most strength when performing about 1 to 5 reps at 85–100% of your single-rep weight capacity (aka, one rep max, or 1RM).

You should perform each rep as fast as safely possible. Safety with lifting involves using proper form for the exercise you are performing.

Hypertrophy training often involves more reps with a lower level of intensity. You should aim to complete between 6 and 12 reps for muscle growth at 75–85% of your 1RM.

Rest period

Rest periods vary between strength and hypertrophy training.

Hypertrophy training should involve a rest period of between 60 and 90 seconds. Too long a rest period may prevent the hypertrophic effect from occurring.

For strength training, your rest period should be between about 3 to 5 minutes. Without sufficient rest, you won’t be able to complete the necessary intensity needed to gain strength.

Sets

Sets are the number of times you perform the same exercise. Using the above example, you may do 3 sets of 10 reps of squats as your full routine with rest periods in between each set.

To train for hypertrophy, you will want to focus on doing between 3 and 5 sets of each exercise.

To train for strength, you will want to focus on about 4 to 6 sets per exercise.

To train for either, you will need to vary your intensity and reps so that you can reach the ideal number of sets.

Exercise selection

Exercise selection can make a difference in your overall resistance training program. Training for hypertrophy or strength benefits from a multiple-joint approach.

In other words, your routines should include exercises that involve several muscle groups and joints in one action — these are often called compound exercises. Squats, deadlifts, and rows are a few examples of exercises that involve several muscle groups in one action.

For hypertrophy, working several groups at once may promote uniform growth. For strength, working multiple groups at once can improve overall strength.

Bringing it all together

The following chart provides a basic example of the difference between training for hypertrophy and training for strength using the same exercise.

Your workout will also look different depending on if you’re a beginner to weightlifting, if you’ve been exercising for at least a few months, or if you’re an experienced athlete or bodybuilder.

When done properly, resistance training is generally safe and effective in building size and strength.

When performing an exercise, you need to make sure you use proper form. If you are not sure how to perform an exercise, you can often find videos, images, or instructions online. You could also work with a personal trainer to learn proper form when performing various strength exercises.

You should also avoid lifting more weight than you can handle.

For example, if you struggle to complete 10 reps of squats with your body weight, you should not add additional weight right away. Instead, focus on finishing your reps and sets at your base level and then increase your intensity once you can comfortably finish your routine.

To help decrease risk, you should focus on building a strong base first. Building muscle size and maximum strength requires a solid foundation to build from, though you will build strength naturally first as you build up your base.

Training for strength or hypertrophy means you’ll need to participate in resistance training. Resistance training for one will naturally increase the other, but there are steps you can take to focus on one over the other.

To do this, you need to modify the fundamental aspects of your workout, including the intensity, reps, rest period, sets, and type of exercises.

As a general rule, you’ll gain more strength by focusing on lifting heavier weight, lowering reps, and executing fewer sets with full rest in between.

By contrast, training for hypertrophy involves moderate weight, higher reps, and more sets with limited rest in between.