# Answer: Lose Weight or Train? Power Increase Explained

• Byrne
In summary, the conversation discusses the concept of whether it is better to lose 5 kg of body mass or to train harder and gain 15 W of power. The example from the class notes shows that a decrease in mass can result in an increase in power, but the question is raised about how this is possible from a physics standpoint. It is suggested that the term "rider" be replaced with "climber" in this context, and it is also mentioned that the human body is not a simple system that can derive power solely from the ratio of masses. It is also noted that even a 250 watt output cannot be sustained forever, using the example of a cheetah chasing its prey.
Byrne
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

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!

Last edited:
"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. :)

## What is the best way to lose weight?

The best way to lose weight is to create a calorie deficit by consuming fewer calories than you burn. This can be achieved through a combination of healthy eating and regular exercise.

## How can I increase my physical strength and power?

The most effective way to increase physical strength and power is through strength training exercises such as weightlifting, resistance training, and plyometrics. These exercises target specific muscle groups and can lead to increased muscle mass and power.

## Can I lose weight without exercising?

Yes, it is possible to lose weight without exercising by creating a calorie deficit solely through diet. However, adding exercise to your weight loss journey can lead to faster and more sustainable results.

## Should I focus on losing weight or gaining muscle?

The answer depends on your personal goals. If your main goal is to lose weight, then focusing on creating a calorie deficit through diet and exercise is key. If your goal is to increase muscle mass and improve physical strength and power, then a combination of strength training and proper nutrition is necessary.

## How long does it take to see results from weight loss and strength training?

The timeline for seeing results can vary depending on individual factors such as starting weight, diet, and exercise routine. Generally, consistent effort and dedication to a healthy diet and exercise plan can lead to noticeable results within 3-4 weeks.

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