How much does weight matter in running?

Just some background info first.
In 2020, I ran regularly 3-4 times per week. Then I got runners knee, life happened and I lost motivation. For the past month, I’ve been running 3-4 times per week again, however, I’ve gained 12kg in weight since then (not muscle). I’m obviously slower now, But using the garmin run pod, today it showed 400w average for a 59 minute 10k. 2 years ago, on a 20k run, it was 396watts for the fastest 10k on that run - similar terrain, so very comparable, however that 10k was 47 minutes. Average HR was 4 beats higher today than 2 years ago and started out higher than usual, due to poor sleep (and alcohol yesterday), so again quite similar.
Another thing to consider, runningas slow as I did today, feels unnatural for me, around 5:30/km I start running “normally”, instead of a short shuffle.
And my lower legs Seem to cramp very easily now compared to before, I see this as a penalty for the extra weight.
So I have a few questions:

  • Is 10kg extra (dead weight) really worth 1min/km? - seems quite a lot
  • where do I go from here to run faster - aside from losing weight, that won’t happen over night. Should I continue long, slow runs with a weird running, or up the pace to my “normal” running form and see where it takes me?

Weight is enormously important in running, and 10kg+ is a ton of weight. At least your goal is clear!

I’ve read 2 secs/pound/mile. Don’t know how accurate but have no reason to dispute.

I’ve read 2 secs/pound/mile. Don’t know how accurate but have no reason to dispute.

I did the same half-marathon for a few years over which time I gained weight. I think that was the formula I found at the time. It was a amazingly accurate for accounting for my slowing times.

I’ve read 2 secs/pound/mile. Don’t know how accurate but have no reason to dispute.

…and my eyeball math once this formula is adapted from freedom units to the OP’s units…~53 seconds/km. (at the 12kg #)

So nearly bang on his 1:00/km.

How did you get to that?
In rough Numbers, 25 poundsx2 =50 seconds Per mile, 31 seconds per km. So thats about half of the deficit. Given the power and HR i roughly the the same, the last 30 seconds/km must be running efficiency, some of it Down to me running with my “weird” jog running form, some of it, lack of running the past 2 years.

Bad eyeball math! I think you’re right.

Weight is nearly equal to fitness in running. It is seriously one of the largest determining factors. Check out graph B on the image below (source: https://bmcsportsscimedrehabil.biomedcentral.com/articles/10.1186/s13102-016-0052-y ).

In athlete’s I’ve worked with, one of the other side effects of extra weight is increased running injuries. Intuitively it makes sense, more stress on the joints, more injury.

As for specific next steps, I would do the following in this order:

  1. Sacrifice intensity but not volume in order to get a steep caloric deficit, 500-1000kcal/day. You can’t out-train a bad diet, so don’t seek volume increases as a mean to weight loss. Down that road madness lies.
  2. Keep volume as high as you can without getting injured. If you swim and bike as well, now is a good time to shift volume there.
  3. As for pace, just do what’s comfortable and sustainable for now. At +10kg you’re not setting and PR’s, wait until you get your weight under control, and once you get close to your racing weight start adding in some intensity and bringing calories closer to baseline.

I understand food and weight can be an emotional and difficult topic, but IMO it’s best to view these things with the same data-driven detachment that we tend to use for training.

https://media.springernature.com/lw685/springer-static/image/art%3A10.1186%2Fs13102-016-0052-y/MediaObjects/13102_2016_52_Fig1_HTML.gif

Weight is nearly equal to fitness in running. It is seriously one of the largest determining factors. Check out graph B on the image below (source: https://bmcsportsscimedrehabil.biomedcentral.com/articles/10.1186/s13102-016-0052-y ).

In athlete’s I’ve worked with, one of the other side effects of extra weight is increased running injuries. Intuitively it makes sense, more stress on the joints, more injury.

As for specific next steps, I would do the following in this order:

  1. Sacrifice intensity but not volume in order to get a steep caloric deficit, 500-1000kcal/day. You can’t out-train a bad diet, so don’t seek volume increases as a mean to weight loss. Down that road madness lies.
  2. Keep volume as high as you can without getting injured. If you swim and bike as well, now is a good time to shift volume there.
  3. As for pace, just do what’s comfortable and sustainable for now. At +10kg you’re not setting and PR’s, wait until you get your weight under control, and once you get close to your racing weight start adding in some intensity and bringing calories closer to baseline.

I understand food and weight can be an emotional and difficult topic, but IMO it’s best to view these things with the same data-driven detachment that we tend to use for training.

https://media.springernature.com/lw685/springer-static/image/art%3A10.1186%2Fs13102-016-0052-y/MediaObjects/13102_2016_52_Fig1_HTML.gif
It’s not that Food is THAT emotional to me. Basically I gained the extra weight because I wasn’t working out and kept eating the same. So, I know I won’t do any PR’s in the near future (maybe a 1k, if I focus on that specifically, since that has never been my focus). I’m probably going to do a diet, losing weight fast, which won’t benefit performance short term, But really, my diet is the same as it used to be and held my weight. So looking for tio perfomance, But loose weight and gain a little bit of speed, performance Will come later.
As for cycling, I’ve been considering it again, since it seems to be more strength than running, on thenother hand, lifting weights May be faster to gain strength, But thats boring as hell. Bit then again, cycling is good for fitness and less strain for joints. I Think I’ll go with adding a run or two, perhaps paced a little faster and maybe 30-60 casual cycling on the days i’m not ready to run. 1. Burning more calories
2. getting more base fitness in the mix

Weight is nearly equal to fitness in running. It is seriously one of the largest determining factors. Check out graph B on the image below (source: https://bmcsportsscimedrehabil.biomedcentral.com/articles/10.1186/s13102-016-0052-y ).

In athlete’s I’ve worked with, one of the other side effects of extra weight is increased running injuries. Intuitively it makes sense, more stress on the joints, more injury.

As for specific next steps, I would do the following in this order:

  1. Sacrifice intensity but not volume in order to get a steep caloric deficit, 500-1000kcal/day. You can’t out-train a bad diet, so don’t seek volume increases as a mean to weight loss. Down that road madness lies.
  2. Keep volume as high as you can without getting injured. If you swim and bike as well, now is a good time to shift volume there.
  3. As for pace, just do what’s comfortable and sustainable for now. At +10kg you’re not setting and PR’s, wait until you get your weight under control, and once you get close to your racing weight start adding in some intensity and bringing calories closer to baseline.

I understand food and weight can be an emotional and difficult topic, but IMO it’s best to view these things with the same data-driven detachment that we tend to use for training.

https://media.springernature.com/lw685/springer-static/image/art%3A10.1186%2Fs13102-016-0052-y/MediaObjects/13102_2016_52_Fig1_HTML.gif
Not sure How to read those graphs? - currently at bmi 27, running a 10k in 59 (not really all out), age 40

It’s not that Food is THAT emotional to me. Basically I gained the extra weight because I wasn’t working out and kept eating the same. So, I know I won’t do any PR’s in the near future (maybe a 1k, if I focus on that specifically, since that has never been my focus). I’m probably going to do a diet, losing weight fast, which won’t benefit performance short term, But really, my diet is the same as it used to be and held my weight. So looking for tio perfomance, But loose weight and gain a little bit of speed, performance Will come later.
As for cycling, I’ve been considering it again, since it seems to be more strength than running, on thenother hand, lifting weights May be faster to gain strength, But thats boring as hell. Bit then again, cycling is good for fitness and less strain for joints. I Think I’ll go with adding a run or two, perhaps paced a little faster and maybe 30-60 casual cycling on the days i’m not ready to run. 1. Burning more calories
2. getting more base fitness in the mix

It;s good that food isn’t emotional, that’s a huge hurdle that a lot of people suffer through. I only put that in there as a disclaimer since it’s a public forum and you never know. As far as what exercises to do that’s completely dependent on you and your goals. The old adage “eat less move more” holds true.

And the graph is explained in the linked study, it basically compares the sampled runners attributes and speeds over common distances. So a 59min 10k is ~9:30/mile. The graphs show their average 40 y/o would be just under 8:00/m and their average 27BMI would be ~8:30.

Weight is nearly equal to fitness in running. It is seriously one of the largest determining factors. Check out graph B on the image below (source: https://bmcsportsscimedrehabil.biomedcentral.com/...86/s13102-016-0052-y ).
I suggest you read that paper with more care and consider the correlational and confounding aspects of the various factors.
“Weight is nearly equal to fitness in running .” Blödsinn
How about “Weight is nowhere near as important in determining running performance as fitness is.”

Weight is nearly equal to fitness in running. It is seriously one of the largest determining factors. Check out graph B on the image below (source: https://bmcsportsscimedrehabil.biomedcentral.com/...86/s13102-016-0052-y ).
I suggest you read that paper with more care and consider the correlational and confounding aspects of the various factors.
“Weight is nearly equal to fitness in running .” Blödsinn
How about “Weight is nowhere near as important in determining running performance as fitness is.”

The biggest difficulty with the study is that there is not a direct connection given between BMI and weekly mileage. Stand to reason that those would be correlated (read: those with a lower BMI average more weekly miles), but when they correct for BMI they don’t address the methodology directly. The charts provided are also adjusted for BMI, so I can’t say much about A and C. I included the article for chart B to illustrate to OP the importance of low BMI on running performance.

400w ? do you weigh 100kg? can do you 400w on the bike for 59 minutes? these run power meters are really terrible at accuracy

400w ? do you weigh 100kg? can do you 400w on the bike for 59 minutes? these run power meters are really terrible at accuracy
92kg
But cycling and running power Can’t really ve compared. And zones are not really the same as well, i’m not really doing training by power on the runs, But it seems to be a fair way ti compare the runs.
Not sure How accurate the running power is, But it seems pretty consistent for the same effort/pace on a flat course. But, the RD pod does Record Ground contact time, stride length kadence and How much I lift my feet vertically, so wether the number is right or not, it should be pretty consistent if my entrered weight is right

Weight is nearly equal to fitness in running. It is seriously one of the largest determining factors. Check out graph B on the image below (source: https://bmcsportsscimedrehabil.biomedcentral.com/...86/s13102-016-0052-y ).
I suggest you read that paper with more care and consider the correlational and confounding aspects of the various factors.
“Weight is nearly equal to fitness in running .” Blödsinn
How about “Weight is nowhere near as important in determining running performance as fitness is.”

I mean its adjusted for training mileage at least. Its not JUST literally “fat people don’t run much and therefore run slow”

Weight is nearly equal to fitness in running. It is seriously one of the largest determining factors. Check out graph B on the image below (source: https://bmcsportsscimedrehabil.biomedcentral.com/...86/s13102-016-0052-y ).
I suggest you read that paper with more care and consider the correlational and confounding aspects of the various factors.
“Weight is nearly equal to fitness in running .” Blödsinn
How about “Weight is nowhere near as important in determining running performance as fitness is.”

The biggest difficulty with the study is that there is not a direct connection given between BMI and weekly mileage. Stand to reason that those would be correlated (read: those with a lower BMI average more weekly miles), but when they correct for BMI they don’t address the methodology directly. The charts provided are also adjusted for BMI, so I can’t say much about A and C. I included the article for chart B to illustrate to OP the importance of low BMI on running performance.

That’s really beyond my question. And then it isn’t somehow.
For the same power, I run a lot slower now having gained weight. So the real question is. If I loose 12 kg over night, Will my 10k be 12 minutes faster tomorrow? - the answer is probably a “no”, But that’s pretty much the though behind this. I know I had better aerobic fitness 2 years ago, But one thing is bad fitness, the other being the weight you carry. Now, this was just a comparison of my run today, that coincided with similar Numbers of a longer run 2 years ago (again, that was km 5-15 on a 20k long run). However, 5k race is currently 8 minutes slower than 2 years ago, But that Also comes with the knowledge of pacing a speed you Can hold for 5k, I have no idea What it really is right now. From What I Can conclude after 1 month of taking up running is that 1. I’m slow, very slow 2. My fitness probably isnt THAT bad, i’m just fat 3. I need to loose weight to run faster 4. I’m very cautious about intensity given my previous knee injury, especially with added weight

Weight is nearly equal to fitness in running. It is seriously one of the largest determining factors. Check out graph B on the image below (source: https://bmcsportsscimedrehabil.biomedcentral.com/...86/s13102-016-0052-y ).
I suggest you read that paper with more care and consider the correlational and confounding aspects of the various factors.
“Weight is nearly equal to fitness in running .” Blödsinn
How about “Weight is nowhere near as important in determining running performance as fitness is.”

The biggest difficulty with the study is that there is not a direct connection given between BMI and weekly mileage. Stand to reason that those would be correlated (read: those with a lower BMI average more weekly miles), but when they correct for BMI they don’t address the methodology directly. The charts provided are also adjusted for BMI, so I can’t say much about A and C. I included the article for chart B to illustrate to OP the importance of low BMI on running performance.

That’s really beyond my question. And then it isn’t somehow.
For the same power, I run a lot slower now having gained weight. So the real question is. If I loose 12 kg over night, Will my 10k be 12 minutes faster tomorrow? - the answer is probably a “no”, But that’s pretty much the though behind this. I know I had better aerobic fitness 2 years ago, But one thing is bad fitness, the other being the weight you carry. Now, this was just a comparison of my run today, that coincided with similar Numbers of a longer run 2 years ago (again, that was km 5-15 on a 20k long run). However, 5k race is currently 8 minutes slower than 2 years ago, But that Also comes with the knowledge of pacing a speed you Can hold for 5k, I have no idea What it really is right now. From What I Can conclude after 1 month of taking up running is that 1. I’m slow, very slow 2. My fitness probably isnt THAT bad, i’m just fat 3. I need to loose weight to run faster 4. I’m very cautious about intensity given my previous knee injury, especially with added weight

I would say if you lost 12kg overnight your 10K would be a helluva lot faster tomorrow.

Just lose the weight. You will run faster. Not complicated.

heavy fast runners… are anomalies. big ones (pun intended).

For the same power, I run a lot slower now having gained weight. So the real question is. If I loose 12 kg over night, Will my 10k be 12 minutes faster tomorrow? - the answer is probably a “no”, But that’s pretty much the though behind this. I know I had better aerobic fitness 2 years ago, But one thing is bad fitness, the other being the weight you carry. Now, this was just a comparison of my run today, that coincided with similar Numbers of a longer run 2 years ago (again, that was km 5-15 on a 20k long run). However, 5k race is currently 8 minutes slower than 2 years ago, But that Also comes with the knowledge of pacing a speed you Can hold for 5k, I have no idea What it really is right now. From What I Can conclude after 1 month of taking up running is that 1. I’m slow, very slow 2. My fitness probably isnt THAT bad, i’m just fat 3. I need to loose weight to run faster 4. I’m very cautious about intensity given my previous knee injury, especially with added weight

  1. You are slower because you are less fit, not because you are heavier.
  2. Your fitness probably IS that bad (relatively).
  3. You will improve your 5km time from what it is now (full effort) by training more, not by focusing on weight loss.
  4. You do not NEED to lose weight to run faster.
  5. The speed work / intensity you need to incorporate will have to be introduced with care because (justifiably or otherwise) you are concerned about a repeat of previous knee injury. Cycling will help the CV aspects which you can do without knee concerns.
    I recommend you get a speed baseline (not faffing with so called ‘power’) by running a 5km as hard as you (mentally) can/feel sensible. And take it from there.

400w ? do you weigh 100kg? can do you 400w on the bike for 59 minutes? these run power meters are really terrible at accuracy
92kg
But cycling and running power Can’t really ve compared. And zones are not really the same as well, i’m not really doing training by power on the runs, But it seems to be a fair way ti compare the runs.
Not sure How accurate the running power is, But it seems pretty consistent for the same effort/pace on a flat course. But, the RD pod does Record Ground contact time, stride length kadence and How much I lift my feet vertically, so wether the number is right or not, it should be pretty consistent if my entrered weight is right

+1

I have Stryd pod, and my easy run pace is a higher power reading than my cycling FTP.

“If I loose 12 kg over night, Will my 10k be 12 minutes faster tomorrow? - the answer is probably a “no””

Various research has suggested that the correlation is between 1 and 3 s / lb / mile. Like the previous poster, I think 2 s / lb / miles is a pretty good rule of thumb. So, if you were to lose 12 kg, holding all else equal with no gain or loss in fitness, I’d expect you to run 52 s / mile faster, or roughly 5 minutes faster for a 10K.

You could try putting a 25 pound weight in a backpack and see how much slower you ran in an all-out 10K. I know I would run a heck of a lot slower.