Walking and other aerobic exercises are often looked at as poor muscle-building exercises. Some even look at cardiovascular activities as counterproductive to muscle growth. It is believed that doing too much cardio can create a catabolic environment. This catabolic environment can lead to the catabolization of muscle tissue.
This scenario might be true if done to the extreme, For example, training for a marathon or not eating enough calories and protein. But this is also true of bodybuilders. If they train too much and do not get enough rest, calories, and protein, they will often lose muscle mass due to the catabolic processes driven by cortisol, the stress hormone.
This article will examine some exciting studies showing that cardio-related activities and exercises can build muscle. The studies we will look at will rest the notion that persists to this very day that cardio is bad for muscle growth and will show how aerobic exercise like walking can help build lean muscle mass.
Does walking build muscle?
Walking builds leg muscle if done routinely and at a high enough intensity to challenge the muscles and provide enough stimulus for protein synthesis and growth to occur.
The first study we will look at was done over 20 years ago and looked at skeletal muscle hypertrophy in untrained and sedentary subjects between the ages of 20 to 80. The test subjects walked or jogged five times per week, and the intensity and duration of the walking or jogging were increased every two weeks until they reached 85 percent of their max heart rate. At the end of the study, the researchers noted a 9 percent increase in the thigh muscle size.
Another exciting study followed a large group of subjects aged between 20 to 86 years of age. These subjects fell into two groups. One group was composed of untrained sedentary individuals, and the other group was highly trained individuals who did cardio regularly. They found that the highly trained cardio group individuals had higher grip strength and leg strength. The researchers concluded that these high strength levels were related to higher muscle mass levels in the cardio-trained group.
These two studies demonstrate aerobic cardio-based exercise such as walking does build muscle, contrary to what most people think and will tell you.
Don’t I have to lift heavy weights for muscle growth?
It is a common misconception that you have to lift heavy weight to stimulate muscles to grow. Lifting heavy loads does stimulate muscle growth, but it is not the only way to stimulate skeletal muscle growth. Studies show that lighter loads or weights can be just as effective for building muscle as heavy loads or weights. For more on training with light weights, check out our article on building muscle with light weights.
One interesting study, in particular, looked at this question and devised a well-structured study examining three different leg workout protocols. They had three different groups who all did different weights for leg extension exercises. The groups are as follows:
- 3 sets of 30% 1RM to failure
- 3 sets of 80% 1 RM to failure
- 1 set of 80% 1RM to failure
Each group performed their given weight range to muscular exhaustion or failure. They found no difference between the groups in terms of muscle growth. Each group increased skeletal muscle by 7 percent.
This study is relevant to walking and building muscle because walking is similar to high-volume, low-weight leg exercises. If high volume, low weight leg exercises can produce just as much lean mass as heavy weight and low volume, this means walking can be an excellent muscle-building exercise.
How does Aerobic training compare to Resistance Training for inducing muscle hypertrophy?
Resistance training is the default or gold standard for eliciting muscle hypertrophy, but how does aerobic or cardio-based exercise like walking compare in terms of stimulating muscle growth. According to a study done using two groups, one group did resistance training while the other group did cardiovascular training like running or walking. After 12 weeks of study, they found that the increase in the size of the biceps femoris was 9 percent, and this was the same across both test groups. This study again shows that cardiovascular training like walking can stimulate muscle hypertrophy in the muscle groups used. In the case of walking or running, this would be the leg muscles.
These studies show that aerobic exercise can be as effective for muscle hypertrophy as the gold standard of resistance training. The fundamental setback to aerobic training for building muscle is that most aerobic or cardio-based exercise is done mainly using your leg muscles, so the leg muscles will be the only muscles to grow in size. There are a few exceptions like swimming, but most are leg centric like running, cycling etc. So aerobic training can help develop muscular legs but does not help you build a muscular upper body.
Summary for walking and muscle hypertrophy
The evidence is clear that cardiovascular exercises like walking are good at stimulating increases in muscle size and strength. The critical thing to note is that muscle growth is only stimulated in the muscles being worked by that aerobic exercise. For the case of walking, you are using the major muscles of the legs, and these include:
- Tibialis anterior
These are the muscle groups in which you can expect muscle growth if you walk often enough and at an intensity level high enough to stimulate the anabolic process. You definitely cannot use walking as an exercise to help you build muscular arms or a muscular upper body, but you can use walking to build muscular legs.
The information contained within this article is not intended to be taken as medical or health advice. always talk with your doctor about medical and health information.