Before I answer the entitled weighty question, I want to clearly support the idea that almost anyone can run and we don’t have to be preoccupied with weight or weight control to participate successfully in our sport. Age group runners come in every size and shape. One of the great things about cross-country and track in middle or high schools is that it is a no-cut sport. Everyone can participate. We even have the Clydesdale category in triathlons to recognize the bigger runners.
Ok, now to the question of whether weighing less can improve your running. The answer is a qualified yes.
VO2max (the maximum amount of oxygen you can process) is measured with body weight as part of the calculation. The more you weigh, the lower your VO2max and the lighter you are the higher your VO2max given the same conditioning. A higher VO2max is a good thing. Though it is not the best indicator of performance (it lags behind lactate threshold and vVO2max) a larger VO2max means you do have a larger “tank” to call upon. It is very likely in fact that a more efficient and powerful runner will out perform the runner with the higher VO2max.
So, though the lighter runner will have an advantage over the heavier similarly trained runner there is more to consider. How many of your competitors are trained just like you or you like them? Odds are there are wide variations in preparation. I introduce this consideration because you should address your overall training first in getting faster.
For the very reasons stated above, you want to become more efficient and powerful. You want a faster vVO2max (the minimal pace at which you reach your VO2max). All other paces are a percentage of this pace and so as you speed this up you drag all the other times with it. You also want to be able to process lactate superiorly. These things are accomplished by a comprehensive approach to your training which includes phases which move through getting you stronger (running specific strength), getting your basic speed faster and through race specific preparation. (By the way, notice that none of those phases include miles and miles of mindless “base” training.)
Here are my recommendations regarding weight loss and improving your running performance.
- If your body weight is already within normal ranges your goal should not be related to body weight. Start training appropriately instead.
- If your body weight is below normal ranges you should never consider weight reduction in your considerations for improvement. The adverse health considerations far out-weigh any effect on running (which will most likely be at best minimal and far more likely detrimental).
- If you are truly over-weight you may benefit from weight reduction. Your BMI (body Mass Index) or fat percentage are important numbers to take into consideration not just the number on the weight scale.
As part of a holistic and comprehensive approach to your running you should get a full evaluation of your diet. Do not under any circumstances get into any of the popular or fad diets and absolutely do not get into a low-carb diet. If you do not have an athletic diet, you will not have the energy available to do your workouts as prescribed. To workout, calories are required and carbohydrates are your staple. Therefore you will not be completing workouts at the right paces or completing the distances. If your workouts suffer, you don’t burn the number of calories you should and in the end will lose less weight instead of more.
There are two other points to make. High intensity workouts will have more effect on your metabolic rate (i.e. burn more calories even at rest). Increasing lean muscle burns more calories.
FYI – Each mile you run will burn approximately 100 calories. There are approximately 3500 calories in a pound. This is variable of course depending on the size of the individual, pace, terrain, conditioning/efficiency, etc. But, this figure is an easy and valid ball park figure. Remember, you have to have a calorie deficit at the end of the day to lose weight.
In all my years of coaching I rarely advise a runner to lose weight to get faster. Don’t try to be someone else’s “ideal” weight. If you train better; eat appropriately apportioned, spaced, smaller meals; cut out junk food, alcohol, evening snacks and large late evening meals; your weight will most likely “normalize” for you.
The Running World According to Dean 
Coach Dean,
Persnonally I’ve also felt that I needed to drop 10-15 pounds and that this would help in hill running and with speed. But what I’ve found is that as I’ve been getting faster, I’ve been getting more muscular, and therefore my weight has actually been going up at times rather than down.
I eat sensibly for the amount of training that I do. I found in this last cycle when I was running close to 100 miles per week, I gained about 5 pounds – 5 pounds of muscle I believe, because I my legs felt thicker and stronger.
All of this to say that I agree with your piece here. I don’t typically advise people to loose weight. The only exception I can think of have been some people that are large enough that their knees and hips might benefit from weight loss to avoid injuries.
Coach Joe
coachjoeenglish.wordpress.com
“One of the great things about cross-country and track in middle or high schools is that it is a no-cut sport. ”
Not at my high school I was cut from the team 3 years in a row… the coach would just not let me be on it.
Total bummer AND VERY unusual. It looks like you’ve persevered and are running despite it! Good stuff.
Coach,
I’ve been reading alot about the Stillman method of calculating weight. I’m 5’9 1/2 inches and it says that I non-active normal people are 162 lbs. it says that I should be 10% underneath this weight: letsl just says 155 to be nice. I’m currently 180.
My question is this: is there a formula that you know of that could predict how much time per mile I would gain from just fat loss alone?
There is no way that I am aware of to calculate that accurately. The issue is NOT fat burned – that is marketing at its best. Though there is slightly more fat burned on very long run late-miles there has not been a connection made to BODY fat content. That is the key missing link. You should be concerned with total calories burned (80-120 or so per mile of running) which lead to a deficit between your intake and output. That is how weight is lost.
By the way, when it comes to determining ideal weights every method has been derived from data/statistics on groups of people… not individuals. Body morphology greatly impacts weight. What that means is that all formulas apply to large groups of people not individuals. So be VERY careful in applying some formula and coming up with a “fact” that you should weigh 10% less.
You say “absolutely do not get into a low carb diet”. I have been on a low carb diet (not no carb) since January 2009 and have slowwwly lost approximately 17 lbs. I am nearing my goal weight of 166 lbs and have slowly begun to increase my carb intake…..still avoiding pasta, breads, and other high glycemic foods. I’m training for a half marathon, and have not had any adverse affects from the low carb diet. I actually feel better, sleep better, and seem to recover just as well. I have seen research that supports the fact that the body (and the brain) do very well burning keytones (vs. glycogen) as a primary energy source. Do you have any research that supports the stereotypical “carbo-loading” diet of runners over the low carb diet I prefer? I’m sure there is support on both sides of the fence, but you seemed to have a lot of conviction in your statement, so I wanted to make sure I wasn’t missing something. Thanks.
Scott,
First as I always say, it’s ends up an experiment of one. If something works for you… great! But that has to be viewed as different from recommending it to others. Of course a diet that is well monitored – high or low carb – combined with negative net caloric balance will yield weight loss.
Recommendations and comments I make come not from anecdotal information (or rarely so and I’ll always say it is just anecdotal if I do use it). What I mean is that I read lots of various research on all sides of the fence. I’m a skeptic. I do not just swallow studies hook line and sinker. And I ALWAYS am skeptical of any study done by an entity that has a stake (i.e. money/sales) in the outcome. Also, the evidence is simply overwhelming that any unbalanced dieting and diets do not work long term.
I’m not so sure it’s “conviction” versus taking a stance that is supported by the predominance of research. It works for most people most of the time. For example: it used to be (70s-80s) that carbo loading was a week long process. Deplete then reload. The research shows that the supercompensation in muscle glycogen stores doesn’t require that dramatic starving then feeding of carbs to get that same result. My stance has changed with the research. I’ve heard every idea possible … stories galore on how certain runners do this that and the other… interesting but not compelling – I stick with research. When and if it changes… I’ll be first in line to share it with everyone.
The only thing you have to remember is that carbs are an essential physiological need for energy. Period. No other source can FULLY replace that – i.e. ketones. It is physiologically impossible. Anything used for energy has to be broken down to glycogen to be used for energy. That is a reason why fat is a poor energy source… it takes a long time to break it down compared to carbs.
Keep up the good work, I’m sure you’ll see the results of weighing less in your running.
Thanks. I agree with you. Overall, I’d say if I ran it today, I’d be a few seconds above my race pace goal of 8:02 per mile (a 1 hr 45 min half marathon), so a few more weeks of training combined with a small 6-7 lb. weight loss should get me there no problem. I used Endurox in the past with good results. Once I get to my goal weight, I will begin using it again. I’m not really obsessed with the weight loss – with all the miles, it’s easy to lose a few pounds without even trying. Glad I found your site – it’s great.
Found this site very helpful. I started running 4 months ago in an attempt to lose weight and become more heathly. 13 pounds have come off, I completed a 1/2 the other day (1:58) and I am always looking forward to my run. This type of site–with lots of scientific material–really helps out. Thanks for your knowledge and wisdom.
Dirk,
Congrats on the half… excellent work!
I’m glad you drop by and that all this is helpful… keep it rolling!
Coach,
I’m 25 years old and have been running on and off for the past 6 years. My 5k PR is 15:09 and my marathon PR is 2:29. I have always used a relatively high-carb diet and belief it is required to run at a high level. Do know of any runners with relatively fast PR’s that eat a low-carb diet?
Tony,
Excellent question and the answer is no. Needless to say lots of fat is bad (slow to burn and easy to store). Too much protein – thinking it will help repair muscle tissue after hard workouts isn’t right either – it can be used as energy but it’s slower to break down than carbs therefore not as readily available and excess gets stored AND more is not better. Even the USOC after much collaborative research projects – has come down on the side that at least in the US, there is more than enough protein in our diets EVEN for power events like weight lifting!!!!!! Their recommendation was was for VERY nominal amounts of supplementation and NOT in all cases. Bottom line is that we have plenty of protein in the average western diets UNLESS you are on a special diet of some kind (i.e. vegetarian or restrictive). That leaves us with what an endurance athlete must have to do the workouts required to GET fast… carbs. Keep up your good work…. nice times.
Coach,
I am a 14 year old national elite female runner with a height of 5 ft 5 in. and a weight that fluctuates between 102-106 pounds. I lost a ton of weight this summer due to intense training and stopped getting my period. I was told to gain weight at the doctor but was warned that I could infact run slower. I found this odd because I would assume that reaching a healthy weight (improved health) would lead to improved running as well. I currently run a 19:13 5K and am hoping to break 19:00 by the end of cross country. Is this still possible if I gain weight? Would you agree with the doctor?
Ms. Chocolaterose…
The answer is not that clear cut. First, your health is about long term health and body functions. Your running is training and being as good a runner as possible. If you are underweight you will be at a higher risk for stress fractures, hormone related health issues, AND decrease in muscle mass which DECREASES your power as a runner.
If you are OVERweight then you will probably run slower.
Appropriate weight elite female runners are about 12% body fat. If you are lower than this it is probably not good on any front. But this is also highly individual.
The issue is not about gaining weight per se. It is about having a healthy body weight and body fat content. Increased weight that is LEAN (i.e. muscle) weight will NOT slow you down.
What does that mean on a practical side? Do not force feed yourself to add weight. Eat healthy foods and increase it to match your OUTPUT of energy in quality workouts. Add strength training for lean muscle building. At your age you should NOT be running more and more miles for conditioning. You should be thinking…. quality over quantity.
I’ve been running since February 2013 and struggling as i weigh 64kg and feel my weight is holding me back from increasing my speed. I joined a club and did about 12 races for the year. My best time for a 10km is 1hr18 mins,I run 3 times weekly- 2 x 6km in the week and a 15km weekends if there are no races. I find it difficult to make more time during the week as I hav a family to take care if. I need advice what to do to gett weight down and increase my speed. I hav a stationary bicycle at home and was given advice to cycle on my non run days, not sure if this will help.
First it is difficult to say if weight is holding you back or not. Your body build and height determine this combined with your actual weight. But the thing that I would advise you to do is stopdoing the same workouts and paces. You definitely need to do high inensity workouts… interval repeats, hill repeats etc. These have been shown time and time again to burn not only more calories BUT also burn more calories AFTER the workout. Your 10k times also reinforce this. So though it seems logical yet difficult… if you don’t run fast you won’t race fast.
If you use the cycle – again… the most beneficial workouts to aid both weight and running is interval training.
Your current level of fitness would be greatly enhanced by a combination of increased intensities (#1) and increasing both frequency of workouts and durations overall. Of course the best way to decrease weight is the combination of exercise AND diet. You would have to run the equivalent of 35 miles (almost 60K) to burn ONE pound of fat. That is almost 3 weeks of running for you. Soi, get in tune with your diet. If you are maintaining weight while working out… you gotta decrease calories.