Having lost 10 pounds in the run-up to the 2011 Towpath Marathon, and having successfully maintained or lost weight while running reduced volume due to injury on two occasions, I’ve been asked several times to post my thoughts on diet. For this post, I thought I’d do it in the context of how to manage your diet in your training for the marathon through identifying and striving for an improved race weight.
Note that I didn’t say “ideal” race weight. You’ll see several tools and discussions on the concept of “ideal race weight,” which is based strictly on your height and gender. Frankly, these tools don’t account for the fact that every runner is different. The broad-shouldered former football player will have a different potential weight than the petite former ballerina. Most “ideal race weight” calculators don’t consider the significant negative impact of losing muscle.
However, for a vast majority of runners, especially those coming to the sport later in life, losing at least a little weight will help with their performance. Tools like the Runner’s Projection Utilities can give you a sense of how much weight loss can translate into how much time gain. Looking strictly at the impact of “spreading” your VO2max over a lighter weight, the gains are roughly 1 minute/pound (2 minutes/kg) in the marathon if you are in the 20-25 BMI range (give or take a few points), and can be more significant if you are above that.
Like most aspects of your training, it helps to have a goal. A reasonable weight loss target (if that’s your primary motivation) is one to two pounds per week. However, knowing that you will need sufficient energy to train, you may want to moderate this goal to 0.5 to 1 pound per week. Again, every runner is different, and you may be able to afford more weight loss if you are starting from a higher base.
Calculating Your Target Calories
The first point to understand is that it takes a 3,500-calorie deficit to lose a pound. You can calculate your daily calorie needs outside of your training based on your gender, height, weight, and activity level. You can also determine the calories you will burn while training through other calculators, or by roughly estimate that you’ll burn:
- Around 100 calories per mile (62 calories / km) if you weigh ~120-150 lbs. (54-68 kg)
- Around 120 calories per mile (75 calories / km) if you are ~150-180 lbs. (68-82 kg)
- Around 140 calories per mile (90 calories / km) if you are 180 lbs. or above (82 kg or greater)
Instead of worrying about calculating each and every week, it may be best to just take the total mileage over your training plan and determine the average weekly amount of extra calories you will burn. So, as an example, if your total is 940 miles (over an 18 week plan (an average of 52 miles (84 km) / week), and you weigh 174 lbs. (79 kg), your extra burn will be 6,250 calories per week.
Now, in this case, you can see why even losing a pound per week may be aggressive. Since each pound is 3,500 calories, this means you can only take in an extra 2,750 calories per week during your training, or less than 400 extra calories per day. It’s likely you’ll need more than that to avoid feeling constantly peckish. So it’s wise to do a sanity check at this point and reconfirm your goal.
Once you set your goal and calculate the weekly deficit needed, you can set your target weekly calorie intake. Note that I find it easier to work in weeks than days, as it’s easy to go crazy over missing a day, and each day will vary both in terms of miles run and your appetite. Sticking with the above example and assuming a “somewhat active” lifestyle outside of running, and further assuming you are 5 feet, 11 inches tall, and further assuming a more reasonable 1/2-pound (~0.25kg) per week target, you find:
- Base calorie needs = 2,400 / day (16,800 / week)
- Extra calorie needs = 6,250 / week
- Desired deficit = 1, 750 / week
- Total calories / week = 21,300 (averages 3,050 per day)
How to Get There
You can find a million different ideas for improving your diet. I’m not promoting any particular approach as frankly, I’ve tried nothing that unique. Whether you go the paleo route, opt to be a vegan, need to go gluten free (note, I wouldn’t recommend a low-carb diet as a runner), or whatever, the fundamental formula is the same – your weight changes are driven by the calories you take in minus the calories you burn.
That being said, the mix does matter some in being sure you have the right kind of fuel available for your training. Guidelines are pretty broad for the recommended balance between carbohydrates (45-65%), protein (10-35%) and fat (20-35%). Given that your two biggest concerns will be (a) having appropriate types of energy available when you run, and (b) promoting muscle recovery and, to some extent, growth, you will want to shift the mix you take in to carbohydrates and protein, so opt for the higher end of those respective ranges, especially on the “extra” calories you consume to offset your training.
To control your diet, it’s helpful to actually track your calories, as you may be surprised by what you take in. The LiveStrong Daily Plate app is a handy way to do this. Just the hassle of entering the data and finding your consumption will discourage you from the occasional nibbles that often go “undetected” in your mind but that can add up to a few hundred calories per day. It can also raise your awareness to the big bugaboo of dieting, and that’s portion size – being honest on this is critical to calorie-tracking (and diet) success.
It is also helpful to keep your diet as steady as possible, avoiding big splurges on days that you run long, for example. Obviously, you will be hungrier and thus eat more on such days, but the goal shouldn’t be to take back in all that you burned (otherwise, it gets tough to restrain yourself accordingly on your rest days). Smoothing things out will help you better manage your appetite too.
If you find a disruption in your plan due to injury or other constraints, you’ll obviously need to adjust your intake down a bit too. Your metabolism may be higher so your daily burn rate may increase a small amount, and any cross-training you do will help, but don’t overestimate this.
Tips and Tricks
Having played with controlling my calorie intake for a few years now, I’ve found some “best practices” that can help you better manage things, and specifically to avoid putting yourself into a situation where your urges can get the best of you.
- Keep it simple and practical – Trying to train for a marathon will take a lot of your mental energy, leaving you less capacity to experiment with radical changes to your diet. Therefore, stick to the fundamental approaches you use in your diet now, but look for opportunities for simple substitutes, snack reduction, or portion control.
- Pack your lunch and all snacks – If you provide only for a constrained (but reasonable) amount of calories over the finite period if time you are at work (if you work), you can avoid the need to fill up on unpredictable “junk” calories from fast food or the vending machines.
- Empty your pantry and refrigerator of temptations – If you can’t resist the nightly beer (tallying up to over 900 calories per week), then don’t keep it around. If you have family that likes their snacks, consider making it a family effort to the extent possible. You can find comfort in means other than food.
- Fill up on fruits and vegetables – While some criticize the sugars in fruit, the reality is that it generally provides a quick energy source. Vegetables in particular have a low calorie density, meaning they can make you feel full without using up your calorie allocation. And, as a runner, you can benefit from small amounts of additional salt, so this can help add some flavor.
- Look for opportunities to substitute “lean protein” options – A quick way to reduce calories without reducing consumption is to look for chicken- or turkey-based alternatives to fattier meats, or to even substitute in soy options. This can be done for such items as meatballs, sausages, bacon, and other foods that are dense in fat calories.
- Choose whole grains over refined grains wherever possible – This is one way to make your carbs “multi-task”, as whole grains provide more protein and nutrients. Use whole grain pasta instead of plain pasta, brown instead of white race, and, if you do like to experiment, discover the joys of other grain alternatives such as quinoa, bulgur, and barley.
- Don’t fall for “low fat” options – “Low fat” doesn’t necessarily mean “low calories”, since fat is often replaced by sugars, which are also empty in other nutritional value. Look at the calories per serving before deciding whether the low-fat option is right for you.
- Think “eat to run”, not “run to eat” – You’ve probably heard this one before, but it bears repeating. If you need to reward yourself with food every time you run, maybe you aren’t running for the right reasons. Your bigger-intake times should be the night before a long run, not the night after. Again, you will feel hungry and need to replenish, but make sure you are listening to your stomach, not your mind, on this one.
- Don’t panic over small misses – Allow yourself to slip once in a while, recognizing that you have a long time period in front of you. Obviously, if you don’t make progress by mid-way through your program, then you need to relook your approach, but this is why it’s helpful to track weekly intake instead of daily intake, as the latter can fluctuate based strictly on circumstances out of your control (the birthday or holiday party, the night out with the gang, etc.).
- You will gain some weight in the final stages of the taper – As you cut the mileage and, for the last 48 hours or so, start to “carbo-load”, you may well gain back a few pounds. This is normal, and a good portion of that is water (as glycogen holds water in your muscles). In fact, it’s more than normal, it’s good, as that is fuel and fluid you will need come race day, and it will be gone by 20 miles.
Recommendations on your diet can quickly become confusing and contradictory. But this basic advice will help keep you stress-free as you work towards your ideal race weight. Just don’t fall into the trap of assuming you can eat anything you want because you are running a lot. It becomes very easy to take in more than you burn off.