"When considering human-powered equipment, a healthy human can produce about 1.2 hp (0.89 kW) briefly (see orders of magnitude) and sustain about 0.1 hp (0.075

"When considering human-powered equipment, a healthy human can produce about 1.2 hp (0.89 kW) briefly (see orders of magnitude) and sustain about 0.1 hp (0.075 kW) indefinitely; trained athletes can manage up to about 2.5 hp (1.9 kW) briefly and 0.35 hp (0.26 kW) for a period of several hours."[1] 100W on a bike is easy to maintain for several hours, even for non-trained humans. An output of 1hp (750W) only lasts a few seconds. [1] https://en.wikipedia.org/wiki/Horsepower https://en.wikipedia.org/wiki/Horsepower