Don't exercise like that, you'll build muscle! Avoid getting too bulky from training.

**3.** **Don't exercise like this, it will build muscle.**

**Pre-class preparation:**

What is the relationship between exercise and muscles?

Which sports build muscle?

What are some common misconceptions about exercise?

"Minmin, what happened to your muscles?" Minmin's classmate exclaimed in surprise, pointing at Minmin's arms. Although Minmin wasn't particularly beautiful, she possessed an enviable figure, earning her the nickname "Back View Killer." Standing at 1.65 meters tall and weighing less than 50 kilograms, she had a perfect hourglass figure-the best part was her shapely back. Her mere back view alone attracted countless boys. But now, her arms were muscular, drastically ruining her beauty. Such a great figure was ruined! Why had her once-perfect figure become like this? Minmin herself didn't know. After some investigation, it was discovered that Minmin had recently become obsessed with basketball, making it a daily ritual. Basketball is a sport, isn't it? How could she be gaining muscles after playing it?

Why do we get "stronger" the more we exercise?

Do you enjoy watching sports competitions? Or do you have friends who like sprinting, basketball, football, etc.? If you observe carefully, you will notice that basketball players have muscular arms, and football players have particularly well-developed legs... Why do athletes in different sports have larger muscles in certain areas than others? To find out, let's first understand the composition of human muscles.

There are three types of muscles in the human body: cardiac muscle, smooth muscle, and skeletal muscle. When we usually refer to muscles, we are referring to skeletal muscle. Skeletal muscle contraction is the driving force behind human movement. When a muscle contracts with both ends fixed, its length remains unchanged while its tension increases; this type of contraction is called isometric contraction. If one end of a muscle contracts while fixed, its length shortens while its tension remains unchanged; this type of contraction is called isotonic contraction. There is no absolutely isotonic or isometric contraction in any human movement. Various static activities performed by the human body approximate isometric contraction, while dynamic activities approximate isotonic contraction.

We all know that muscles are actually exercised while performing various movements. If we exercise regularly, the structure and function of our muscles will undergo significant changes. Exercise can increase the cross-sectional area of ​​skeletal muscles, a phenomenon known as "work-related hypertrophy".

The increase in the cross-sectional area of ​​skeletal muscle is primarily determined by the force of muscle contraction. In daily life, we often experience muscle contraction during exercise. This contraction causes our muscle fibers to thicken and increase in number. Along with the thickening of muscle fibers, the content of their components, such as myoglobin, adenosine triphosphate, creatine phosphate, glycogen, and various enzymes, also changes. Furthermore, the capillary network in the muscle increases, and the connective tissue in the muscle thickens, thus leading to working hypertrophy of the muscle. Women who want to lose weight will not only fail to lose weight if they engage in exercises that build muscle, but will actually become stronger instead.

Which sports make you stronger?

Seeing this, some women who want to lose weight might panic. Oh no! They thought exercise was for slimming down, but instead, they ended up with bulky arms! Is exercise still effective for weight loss? Actually, as long as you avoid or minimize exercises that build muscle, exercise can still help you achieve a slim figure. Next, let's learn about which exercises can cause muscle growth.

▲Basketball

Seeing the dashing figures of basketball players on the court, many people are probably itching to get on the court and show off their skills. However, if you're a girl who cares about your appearance, I advise you to "only admire from afar and not play," because basketball is a sport played with your hands. It involves passing, throwing, dribbling, rolling, and other techniques with the ball. In other words, your arms are constantly in a contracted state while playing basketball, which gradually strengthens your arm muscles.

▲Sprint

As we all know, sprinting is the act of running a predetermined distance (usually 50 meters, 100 meters, 200 meters, etc.) at top speed on a set track. It requires the human body to maximize its instincts and utilize anaerobic metabolism for energy. Sprinting mainly relies on the powerful forward and backward swinging of the arms with bent elbows and the rhythmic alternation of the legs. During the exercise, the skeletal muscles of the arms and legs contract intensely and rapidly multiple times, which is why sprinters have well-developed arms and muscular legs.

▲Weightlifting

When you think of weightlifting, do you picture female weightlifters? They're all broad-shouldered and muscular, with thick arms and legs. This is because weightlifting relies primarily on the strength of the legs, arms, and waist. During training, the weight of the barbell causes the skeletal muscles to contract intensely, leading to thicker and more numerous muscle fibers. This increases the cross-sectional area of ​​the skeletal muscles, resulting in large, bulky muscles.

▲ Jump rope

All you need is a rope of suitable length and a suitable space to jump rope and achieve weight loss. Therefore, jumping rope is popular among many women who want to lose weight. However, during the process of jumping rope, because your legs rhythmically extend and flex, you can unknowingly develop "carrot legs." Therefore, remember to do some stretching exercises after jumping rope to ensure even muscle distribution and prevent the development of "carrot legs."

To lose weight without becoming bulky, it's recommended to choose gentle, moderate exercises such as aerobics, Latin dance, swimming, and long-distance brisk walking. Avoid high-impact activities like basketball, sprinting, step-ups, and soccer. Regular flexibility exercises can also enhance a woman's graceful figure!

**Common Misconceptions about High-Intensity Exercise Training**

Myth 1: The longer the treatment, the better the weight loss effect.

Some people believe that the longer they exercise during the weight loss process, the better. However, excessive exercise can actually harm the body, such as promoting muscle growth, causing muscle strain, and creating a burden on the body. Generally, the optimal exercise time is 40 to 60 minutes, while gentler exercises, such as Tai Chi and yoga, are recommended for 45 to 90 minutes.

Myth 2: Repeating the same project every day

Some women are rather lazy and like to repeat the same activities every day, thinking that as long as they exercise daily, they'll burn calories. However, they don't realize that repeating the same activity multiple times causes the body to gradually adapt, resulting in fewer calories burned. Therefore, it's best to alternate between running, cycling, and strength training for better fitness results.

Myth 3: Maintaining the same intensity every day

Similarly, just like repeating the same activity every day, if the intensity of exercise is the same every day, our bodies will become sluggish, and fat burning will decrease accordingly. Therefore, it is best to vary the intensity of exercise each day, such as 45 minutes today, 40 minutes tomorrow, and 50 minutes the day after, in order to help the body lose weight.

Myth 4: Repeating the same type of project every day

Some people enjoy doing the same type of exercise, but this only works specific parts of the body. For example, jogging and skipping rope both work the legs and arms. Only by alternating different types of exercise can you get a full-body workout and achieve your weight loss goals.

**Second Lesson in Weight Loss: Exercise for Weight Loss**

Cycling is also a highly effective way to lose weight. If you're willing to cycle to work, you can not only save a considerable amount of transportation costs, but also achieve weight loss.