That rule is for the marathon, not the half marathon. The impact of extra weight on pace is not linear over distance. An extra pound slows you down a lot more on mile 26 when you're experiencing serious muscle fatigue than on mile 13.
That rule is for the marathon, not the half marathon. The impact of extra weight on pace is not linear over distance. An extra pound slows you down a lot more on mile 26 when you're experiencing serious muscle fatigue than on mile 13.
Tom Osler did the original research for this formula by correlating body weight with race times from 5K to marathon. http://www.outsideonline.com/fitness/weight-loss/The-Drop-Zone.html.
Usually with weight loss comes a higher fitness level. There are too many variables for this to be accurate. Sit on the couch every day and eat nothing. You will lose weight but you'll be slow.
It would depend if the weight you are losing is "fat" or "muscle" -- losing "fat" will help you but losing "muscle" may not. Lowering my body fat % by 6% helped me improve my marathon time from 3:20 to 2:58. However, it took about 16 months for this improvement. If you eat well (stay away from process foods), train sufficiently your times will improve but will stabilize at some point.
otter wrote:
Usually with weight loss comes a higher fitness level. There are too many variables for this to be accurate. Sit on the couch every day and eat nothing. You will lose weight but you'll be slow.
There are not too many variables. There is only one - unneeded weight. Sit on the couch everyday and lose weight, and you'll be faster than when you were heavier.
luv2run wrote:
My guess is that there is some point of diminishing returns. As an extreme example (and all too common): a runner starts to lose weight and gets faster and as the weight comes off the performance improves. The runner thinks "Wow, if I just keep losing weight I am going to win ______".
However, at some point the runner is going to reduce energy intake and workouts will start to suffer. The runner may get sick or just not have the energy to train or perform well and times start to creep up again.
My suggestion to folks is to train well and eat well enough to support the training and the speed will take care of itself. I also think that people have an ideal training weight that they can maintain for much of the year and then when in the key competition period drop a FEW pounds and be sharp. Then the weight comes back on. (Not in a Lolo Jones way, but that is a pretty unique case).
I can say from experience that this is true. There's a point where too much weight loss makes it hard to push in workouts and recover after. My BMI was recently a little under 18 (I'm a female) and I put on 5 pounds in just a few weeks, and my running is feeling better already (I run ~18 minutes for the 5k).