The increase of muscle circumference is mostly due to the fact that a large amount of protein accumulated into fat through exercise and became muscle, which gradually increased the muscle circumference.

The growth of muscle strength is mostly due to long-term training, which gradually increases muscle strength and has little to do with muscle circumference. In the case that some muscle girth does not increase, strength will also increase.

Bodybuilders or people who pursue the beauty of muscles generally drink tonic protein powder. The purpose is to transform a lot of protein into muscles through exercise, and the muscles will gradually become bigger, so that the figure will be beautiful and the lines of the muscles will be beautiful.

Bodybuilders tend to pursue the growth of muscle circumference and don't care much about muscle strength, but boxers generally pursue muscle strength, and even many athletes, rather than those who only grow muscles for muscle, pay more attention to muscle strength.

If you are a girl who is losing weight, I suggest that you should pay attention to your muscle circumference and measure your leg circumference and waist circumference every week to see if you have lost fat or gained muscle.

It is best to do more aerobic exercise, which can reduce fat rather than gain muscle. Doing too much anaerobic exercise will make muscles bigger, which is not suitable for girls' figure.

Or you can combine anaerobic and aerobic, which not only increases muscles to make the lines of the body look good, but also reduces redundant muscles.

Finally, back to the question, if the weight is constant, the increase of muscle circumference is accompanied by the increase of muscle strength, otherwise it may not be, depending on the actual situation.