Let me talk about the principle of bicycle dynamometer first. Everyone knows the power formula. Power = power x distance ÷ time. For a bicycle, the distance is the distance traveled by pedaling and turning the crank to drive the wheels. If it is a spinning bike, it will be converted according to the radius and speed of the wheel. So in essence, the principle of bicycle dynamometer testing is that you put pressure on the pedal, which will be converted into torsion for some stressed devices. Dynamometer will get this torque by measuring the deformation of this device, and then use the following formula to calculate it: power = force (deformation measurement of stressed device) x distance (calculated by crank rotation angle, scale ratio and wheel radius) ÷ time (pedaling time) As for why the actual power of the elliptical machine next to me is much higher, my consideration is that when doing elliptical machine practice, the whole body's weight will be pressed on the elliptical machine, and this force will be obviously greater than sitting on it. You can try to get up and ride a bike, and your motivation will be greatly improved. . . But it's hard to last. . . Regarding the rationality of bicycle power, release data to illustrate. The following data is the bicycle strength data of Ben Hoffman, the runner-up of Kona triathlon last year. Hoffman won the second place in Kona last year. KONA is a complete distance triathlon, 3.8KM swimming+180KM riding+marathon running). It can be seen that the bicycle power of professional triathletes can be stabilized in the middle of 250W-300W, and may increase slightly when climbing. It is very important to keep the power output consistent during long-distance riding, otherwise it is easy to burn out (this word is called riding collapse, which means that the strength is too high in a short time and the body output is not well controlled, resulting in a sudden and sharp decline in overall performance, and there is no way to continue).