First of all, we should understand that fat consumption during exercise refers to the whole body fat consumption together, not which part of the body is consumed during exercise, that is to say, exercise will not reduce fat locally. It's just that different parts consume different proportions of fat, and "sensitive" parts will lose more fat.
Secondly, we need to know whether there is too much fat accumulation on our arms. The measurement method can be searched in Baidu's "Measurement of subcutaneous fat thickness". If the fat is too thick, you should exercise accordingly, otherwise the effect may not be good.
Thirdly, aerobic training is often used to reduce fat during exercise, such as running for 40-60 minutes at a time, and then pursuing speed on the premise of ensuring time. If you have a certain foundation, it is recommended to do high-intensity interval training. As for the effect, we should also consider our own physique and diet. Physical fitness, exercise density can be higher, of course, the process of losing fat will be faster. The effect will be more obvious if the diet is well matched and controlled.
Fourth, if you do dumbbell lifting, it is shoulder training. The basic action of arm training is to bend the elbow and lift the arm. In order to reduce fat, the training of target muscle groups is mainly to make muscles tighter, so it is suitable for training with less load, slower frequency and more groups. This is beneficial to slow down the growth of muscle fiber and intramuscular fat consumption, and can control the excessive increase of arm circumference.