I never saw myself as a tube light. Or even a light bulb really. Ignore my intelligence, or lack therefore, and any resemblance to a tube light. Instead, think of the energy that these instruments of light exhibit. Power. Measured in watts. In similar fashion, the human body needs energy to function. The energy is measured in rate of work or energy per second. A normal human body produces heat or energy of 80 watts. This is also your basal metabolic rate.
A few years ago, most of the sprinting I did was in my head. It didn’t require significantly higher levels of wattage than the base rate of 80. Cyclists at peak are able to exert 400 watts of energy continuously. The average Jane can exert 3 watts of energy per kg of weight when performing a physical activity. This translates into about 150 watts. If you are a super athlete, this can go up to 6 watts per kg. If you weigh more, this means you can exert more energy. In this case, bigger is really better. This is why David v/s Goliath is the exception not the norm. However, as with everything in life, this is mixed bag. If you are heavier, it also means you need more energy to move the extra mass. This is a simple explanation of why losing body fat increases overall energy. You have lost weight or mass and retained your wattage.
Are you interested in finding out what your watt is? Hop onto a bike that can measure this. Once warm, pedal as furiously as you can for twenty minutes. The energy meter will measure the energy with which you can pedal. The watts at which you light up if you prefer. Not happy with your illumination? Strength training, focus on nutrition, especially protein and repeated training can improve your watts. If you need a role model, your fellow human has exerted up to 6000 watts of energy even if for just one second.