Answer: Lose Weight or Train? Power Increase Explained

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Losing body mass can enhance an athlete's power output due to reduced resistive forces, allowing them to maintain speed with less effort. In the example discussed, a 75 kg rider losing 5 kg results in an effective power increase of approximately 18 W, illustrating the relationship between weight and power-to-weight ratio. The physics behind this suggests that a lighter rider experiences less gravitational resistance and friction, enabling better performance on inclines. However, the complexity of human physiology means that power output isn't solely determined by weight, as factors like endurance and energy sustainability also play significant roles. Overall, the discussion highlights the nuanced interplay between weight loss and power training in athletic performance.
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EDIT -- I posted this here because I figured its more of a conceptual problem than a HW problem, but if people see otherwise, feel free to delete the post.

I'm having troubles wrapping my head around this one (I've provided the example from my class notes below):

Q: Is it better to lose 5 kg of body mass (assume no change in muscle strength) or to train harder and gain 15 W of power?

Given:
75 kg rider producing 250 W of power

ANSWER:

75 kg / 70 kg = 1.071
In terms of Watts: 250 W x 1.071 = 268 W, ~ 18 W increase

So, depending on the initial weight, the athlete might see as large a benefit from losing weight as training harder.

My question -- how does a decrease in the mass of the rider increase his power producing ability by 18 W? Intuitively, I would think that a rider with lower mass will experience less resistive forces when riding (i.e., gravity when on an incline, kinetic friction) and so can sustain the same velocity as a heavier rider without applying as much force and, therefore, less power.

From a physics standpoint, how does a mass decrease result in an increase in Power as this example suggests (taken from my class notes)?

Thanks!
 
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"Rider"? Climber would be a better description, the riders weight is being treated as the opposing force in this problem.
 
I don't think our bodies are that simple to derive power from the ratio of masses. It seems ridiculous. Even this 250 watt cannot be sustained forever. A cheetah-at it's max speed- should stop pursuing the deer within 40 seconds or so before it gets hyperthermia. :)
 
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