# Force and Power ?

1. Feb 8, 2010

### waynexk8

Force and Power ???

As far as I understand, if I was to accelerate a weight to 80% only, and then no matter the speed of the lift, the average force {strength} will always be the same.

If your RM is 200 pounds, but using 80% = 160 pounds, and your accelerating with the greatest force/speed/strength for 80% of the rep, that is roughly 200 pounds of force being used. Say the rep speed is .5/.5.

However, not average force, as then the force goes nearly down to zero for the last 20% so take off 20% off 200 = 160 pounds.

In addition, if you use a slow concentric at say 2 seconds, full rep is 2/4, you constantly only punching for the whole ROM, thus you too use 160 pounds of average force.

Question 1,

However, I will be able to move this 160 pounds 5 more times in the same time frame as the 2/4 rep, also 5 more times the distance in the same time frame.

So have not in some way used my average force {strength} 5 times ??? And used more power {work energy} ???

As if you shot a putt at .5 of a second to 2 seconds, it is going to go further, thus using more force {strength} power {work energy} ???

Question 2,

Fast lifting,
Weight lifting (free weight, nautilus or universal-type), power lifting or bodybuilding, vigorous effort.

In 1 minute, you burn 10 energy {calories}

Slow lifting,
Weight lifting (free, nautilus or universal-type), light or moderate effort, light workout, general

In 1 minute, you burn 5 energy {calories}

Thus, whatever activity you do in life, the faster you do it in the same time frame, the more energy {calories you burn doing it fast.

New video proving my point.

Wayne

Last edited by a moderator: May 4, 2017
2. Feb 8, 2010

### waynexk8

Re: Force and Power ???

The main issue in the debate, is that another person on a forum, I call D. Says that the force {strength} power {work energy} used in all rep speeds are equal !!! However, I pointed out to him, that he has to include the dimension TIME, to make the study fair and non biased. However, he seems to think that me saying you can do 6 reps {reps is repping up and down with a weight in the gym} at .5/.5 {.5 concentric .5 eccentric} = 6 seconds to his 1 in the same time frame at 2/4 – 6 seconds, as I explained above, makes no different.

Here is a little on what D. Wrote. But as I keep saying to him W = mg
(Weight = mass x acceleration of gravity) Yes it would spend more, a huge amount to get it moving, then lots to keep it accelerating, then still quite a lot at a constant speed.

In addition, he does not include air resistance, in his equations ??? I told you it is far harder to lift thick short plates to long thin ones. And go try lifting a 112 pounds bag of cement, and then put the same on a bar, you will find it far easier on a bar, because on air distance, friction, gravity, leverage and torque.

Wayne