If you're a 220 pound guy...all else being equal, how much time would be shaved off of your 5k if you dropped 40 pounds?
If you're a 220 pound guy...all else being equal, how much time would be shaved off of your 5k if you dropped 40 pounds?
about tree fiddy
Ha Ha. tree fiddy
But actually I guess that's pretty much the right answer.
I've always heard 1 minute improvement per 10 lbs you lose.
I’m going to work backwards on this one, bear with me.
Being conservative, every pound of weight above “ideal” is worth 2 seconds per mile in a marathon.
40 Pounds = 80 seconds per mile
Let’s assume you ran a 4:00 Marathon (9:09 pace) at 220. All things being equal, if you weighed 180, you would have run a 7:49 pace for a 3:25 marathon.
Per the Tinman Calculator:
A 4:00 marathon “converts” to a 25:07 (8:04 pace) 5K
A 3:25 marathon “converts” to a 21:28 (6:55 pace) 5K
If you lack running fitness, it may be drastically different in either direction.
Need to know height and current time. If you are 7' and running 18 minutes, probably 2 minutes. If 5'8" and current time is 26 minutes, probably 6 minutes.
You will most likely be faster. That’s about all anyone can tell you given the amount of I for given.
For example you can be 6-7 and 220 and be in fairly decent shape. If you’re 5-9 at that weight, well that’s different isn’t it? There are too many variables to throw a formula at it.
CosbyBabies wrote:
Being conservative, every pound of weight above “ideal” is worth 2 seconds per mile in a marathon.
I’ve heard this “2 seconds per pound” quoted a lot but I’ve never seen a study to back it up. Any links? I assume it should be per pound of excess fat, as muscle wouldn’t have quite as negative effect even though runners may carry more muscle than their “ideal” weight.
I saw a study years ago that found it is 5 seconds per mile for each pound that you are over your ideal race weight. It held for about the first 4-5 pounds and then started dropping rapidly. I assume that the 20th pound is only worth 1 second per mile.
Can you provide an answer with less math involved please???
CosbyBabies wrote:
I’m going to work backwards on this one, bear with me.
Being conservative, every pound of weight above “ideal” is worth 2 seconds per mile in a marathon.
40 Pounds = 80 seconds per mile
Let’s assume you ran a 4:00 Marathon (9:09 pace) at 220. All things being equal, if you weighed 180, you would have run a 7:49 pace for a 3:25 marathon.
Per the Tinman Calculator:
A 4:00 marathon “converts” to a 25:07 (8:04 pace) 5K
A 3:25 marathon “converts” to a 21:28 (6:55 pace) 5K
If you lack running fitness, it may be drastically different in either direction.
If a 220 pound fella has less than 7.5% body fat, losing 40 pounds may make him anemic, thus he would have no improvement at all.
Some women are ruined following these simple nonsense theories. Some women are naturally curvy. If these women with natural curves are already under 15% fat and attempt to lose weight, losing weight may make one ill and no improvement at all.
Predictor wrote:
Need to know height and current time. If you are 7' and running 18 minutes, probably 2 minutes. If 5'8" and current time is 26 minutes, probably 6 minutes.
What if you're 5'7" and your current time is 29:15? Asking for a friend.
bartholomew_maxwell wrote:
If you're a 220 pound guy...all else being equal, how much time would be shaved off of your 5k if you dropped 40 pounds?
If you like Jack Daniels' VDot theory you can simply calculate it, because the absolute oxygen uptake values are devided by weight for these relative values. Going down from 220 to 180 lbs would increase your VDot value by 22.2% then. For a 24:00 5 k this may result in a 20:15, for a 20:00 in a 16:50, for a 17:00 in a 14:15.
In the end you can say it is about 2.5-4 min depending on your performance level. Of course closer to 4 min if you are 40+ pounds overweight and not just tall and muscular.
slothlike wrote:
Predictor wrote:
Need to know height and current time. If you are 7' and running 18 minutes, probably 2 minutes. If 5'8" and current time is 26 minutes, probably 6 minutes.
What if you're 5'7" and your current time is 29:15? Asking for a friend.
According to my calculation this would be a 24:45 after losing 40 pounds.
However, nobody loses 40 pounds magically. Most people don't just eat less, but do increase the amount of physical activity in the process, and of course this might lead to even higher time improvement than just plain weight loss.
If you're a lifter you can't look good with your shirt off and maximize your running at the same time. Pick one or the other.
23 minutes.
Body weight plays a huge role. In fact, most of the differences in my race results are explained simply by the difference in my body weight at each point in my life. If you use a resource like Jack Daniels VDOT calculator, everything is given in mL O2/kg/min (how much oxygen a given runner can process per minute per kilogram of body weight). Lugging around extra body weight that does not help propel you forward, slows you down. Period.
For example, take a 220 lb person who can a 25:12 5k. That time corresponds to a VDOT of 38 mL oxygen per kilogram of body weight per minute. Multiply the VDOT by the runner's bodyweight to get their gross oxygen consumption rate: (220 lb/2.2) * (38 mL/kg/min) = 3800 mL/min. That's basically the size of their engine.
Put the same size engine in a lighter car, and the car goes faster. Now assume this person loses 40 lbs. If they did it by training, chances are their aerobic engine actually got bigger, but let's assume it stayed the same size. Now they have a total capacity of 3800 mL/min, but they weigh 180lb/2.2 = 82 kg. Even without increasing that engine size, their VDOT has increased to (3800 mL/min) / (82 kg) = 46.4. Without training their engine, that person has increased their VDOT from 38 to 44.4. Going back to Jack Daniels VDOT tables, and that person can now run a 22 minute 5k.
The HUGE asterisk on this whole thing is that losing weight can be achieved a lot of different ways. One could starve themselves drastically and have their body destroy valuable muscle tissue, meaning the aerobic engine shrinks. Or some people who are already tiny, especially females, will develop hormonal problems when their weight goes too low. Think of female runners who stop having their periods or who men who develop low testosterone - the weight savings come at the cost of the person's aerobic capacity and their ability to recover from workouts, which ultimately dooms them. Weight is tricky. I had to include this asterisk paragraph to combat all the rhetoric on this site which only focuses on weight. Yes, losing weight will make you faster under the right conditions. But there are ways it can hurt you. That is not the takeaway from my post if we are talking about a 220lb individual.
You will always be disappointed if you go looking for studies to back these things up. They are often a combination of a coach's own rules of thumb, plus some random study from 1971 that has 3 participants.
Oh god why did I write all this. I should have read the existing replies. Sorry
numbers guy wrote:
Oh god why did I write all this. I should have read the existing replies. Sorry
because you had some important information to supply about how starving onesself is dangerous.