relationship between power and body fat

Question

When throwing a punch it's often recommended one throw ones weight into it. Does it make much of a difference with what constitutes that weight?

For example, say you have a guy with 130lbs lean mass and 10lbs fat (ie. 7% body fat) and another guy with 130lbs lean mass and 50lbs body fat (ie. 38% body fat). Would the 38% body fat guy be able to throw a more powerful punch simply because he weighs more?

If so than this also makes me wonder... what other "exercises" would being overweight be an asset? Like would the 38% body fat person in the above example be able to do better at standing med ball tosses than the 7% body fat person simply because he'd have more weight to leverage when tossing the ball?

Answer 1

The person with the higher body fat may or may not be able to throw a more powerful punch. Punching is very technique driven, and a smaller person with better technique will be able to punch harder/quicker than someone with lesser technique.

However, if we assume that two individuals have the same technique, the person with the higher body fat may have a slightly more damaging punch just because of the extra weight moving with the arm. An arm is generally about 5% of total body weight, so in your example (40 lbs of difference) there would be about 2 lbs of direct extra mass on the arm, which would, in turn, make the punch slightly more effective. (Force = mass x acceleration)

Where it could make a bigger difference is in receiving punches, in that larger massed opponents will spread the impact out slightly, and there is more fat in between the impact point and subsurface structures.

The main point behind telling someone to "get their weight" behind a punch more addresses technique and the type of punch than anything. A jab, for example, is mainly driven by arm and shoulder muscles and doesn't (generally) cause much damage. A cross (reverse punch in martial arts) starts with the planting of the feet, torques up through the legs and hips, engages the trunk muscles, and drives all that force through the impact point. That's what is generally meant by "get your weight behind it", rather than just a straight application of more mass.

Answer 2

The lower your body fat, the faster you fatigue and also quicker you feel stressed.

don't take me wrong on this comment Fat is a very slow release source of energy and when the protein source gets depleted in your body, the system kicks in to burn fat as a fuel to keep it up. This is the main reason for the fatigue.

Even in strength training having a reasonable amount of fat (Not over, Not under) will keep your joints from being damaged unless you deliberately draining your body from fat for a competition. During this period, you should watch out for the good form and controlled weight to prevent injury.1

This point comes into action in most of heavy weight lifting sports and joints are padded and lubricated by fair amount of stored fat. (and possibly can be a positive). However those athletes benefit from a very strong cardiovascular system and having that extra weight won't be phrased exactly as being "overweight". Excessive fat can be the cause of lot of problems in the body and a good starting point for most issues.

"Conclusion A lower daily fat intake and lower percentage of total energy from fat were associated with increased injury risk among competitive female runners. Lower energy intake and lower energy availability approached, but did not reach, a significant association with overuse injury in this study. By documenting these risk factors, it is hoped that future research will continue to investigate their role in injury development, thus leading to better strategies to predict and reduce running injuries in women."1

Additional resources for self-read:

Eating Habits That Reduce Injury Risk

LESS FAT IN DIET LINKED TO INJURY RISK IN RUNNERS

1)Gerlach, Kristen E., et al. "Journal of the International Society of Sports Nutrition." Journal of the International Society of Sports Nutrition 5 (2008):