Energy/calories and average force

[waynexk8]

Energy/calories and average force.

If you look in all Nutrition books and sites, you use/burn far far far more energy/calories when doing the same activity twice as fast. However someone says as the average force is the same in the below example, that you use the same energy/calories, I say this is not true, as the example 1 below is traveling faster and for more distance using more power. {work energy}

1,
Bench press 80 pounds or 80% of your RM {repetition maximum} 6 times up and 6 times down, 1 second up and 1 second down = 12 seconds in all. 1m each way = 12m in all.

2,
Bench press 80 pounds or 80% of your RM {repetition maximum} 1 time up and 1 time down, 6 seconds up and 6 second6 down = 12 seconds in all. 1m each way = 2m in all.

Wayne

 

[uart]

someone says as the average force is the same in the below example, that you use the same energy/calories

Reference "someone" please!

 

[uart]

Hi Wayne, I would have preferred to see what exactly "someone" said so I knew exactly what case we were discussing, but let me try anyway.

First off let me say that you will burn more calories doing the 6 presses of option "1".

Where I'm guessing that you are running into conceptual problems is in trying to equate energy consumption of the human body to the amount of useful output work. Typically with exercise the amount of metabolic energy used by the body is far greater than the amount of useful work performed. In fact a significant proportion of the extra (above basal metabolic) energy consumed during exercise often occurs after the exercise session has completed, due to the increased metabolic rate induced by the exercise! (which can last for quite a long time after the exercise session is over).

 

[uart]

As for the bench press repetitions, there is actually no net work done in either case. On the up press your arms are doing work on the weights and on the down press the weights are doing work on your arms. Of course your arms are not able to "regeneratively brake", so you actually use metabolic energy on both the up press and the down press. In the end however it's all wasted energy and no net work is done on the weights.

 

[waynexk8]

Hi there uart, thanks for your time and answer, I will try and get the person to tell me exactely what he's means.

Wayne