It may sound impossible, but a surprising number of people who are training for a marathon find they actually gain weight as a result. Really? You ask. But how? While you’re putting so much time and effort into conditioning your body, weight gain often comes as a frustrating surprise. Here are some reasons why you’re actually gaining weight during your training, instead of losing it.
A calorie is not just a calorie. Just because you’ve burned 1,300 calories on your last run, doesn’t mean you are now allowed to eat a box full of cupcakes (sorry). Your body will digest certain foods differently depending on the various nutrients in them.
For instance, a high-sugar diet may stimulate the liver to release more harmful fats into the bloodstream and also raise your blood pressure. And overeating becomes very easy when you are burning more calories per day than you’re used to. You need to come up with the right nutrition strategy while you’re training and especially for the actual race day so you are not running on empty. You also don’t want to wait too long after your run to eat or else this could also lead to overeating later on in the day since your body needs to be replenished with nutrients depending on how depleted your system is. Preparing meals that are rich in nutrients is essential to not only preventing unnecessary weight gain, but to feed your body what it needs during training.
Your performance and training may also suffer if you’re not paying attention to when you eat. According to The University of Chicago Medicine Orthopaedics Center, it’s best to eat 3 hours prior to working out so you have time to digest and store the energy. However, if you can’t allow for that much time before your morning run, avoid foods that are high in fat, protein, and fiber since they digest slowly and stay in the digestive tract longer.
Gaining Muscle Mass
Muscle mass is more dense than fat mass, which means that one pound of muscle takes up less room on the body than one pound of fat. If your body looks the same or more toned, yet you are heavier on the scale, you can blame additional muscle mass as the reason why you’ve gained weight. If this is the case, then it’s time to celebrate! You’re training hard and you will be even more prepared to cross that finish line come race day. If you’re training properly for a marathon, you’re combining strength training with cardio as you prepare for race day, and doing so will definitely increase your chances of gaining more muscle.
Storing More Glycogen
An increase in glycogen stores could also be the culprit to your weight gain, especially if you’re a novice marathoner. For every ounce of glycogen, the body also stores three ounces of water, which can attribute to those extra pounds on the scale. This is why relying on a scale isn’t the best way to go when you want an accurate reading of your fitness progress. That one number on the scale isn’t an accurate portrayal of the percentage of muscle or water weight you’re carrying around. While you’re training, your water weight will fluctuate a lot. Having more glycogen stores means being able to store extra fluids, which is a good thing when it comes to staying hydrated throughout those long distance runs.
Carbohydrates are stored as glycogen in the muscles and liver and you can only store so much, which is why it’s important to strategize how you will replenish those carbohydrates during your run. This is also why carb-loading is needed before the day of the marathon so your glycogen stores are full. Glycogen is the primary fuel your muscles use for energy production and your key to marathon success!
Overestimating Energy Expenditure
To prevent overeating or consuming too many calories during a long run, you need to accurately keep track of how many calories you’re losing along with your hydration rate. All of those gels, chews and bars pack in a lot of calories, and you might not need to have them before or during your run depending on how long your run is that day.
According to the University of Chicago Medicine Orthopaedics Center, high-intensity aerobic exercise for 1 hour will deplete glycogen stores by about 55 percent, and by 2 hours, your glycogen stores are begging to be replenished. It’s estimated that in this case, consuming about 60 grams of liquid or solid carbohydrates with each hour of exercise can benefit your performance.
You can make sure you meet these needs by keeping a sports drink or gel handy that contains between 4-8 percent of concentration of carbohydrates. Also, post-workout, the best way to replenish glycogen stores is to eat foods that have a higher glycemic index such as a banana or white bread. This may answer your question as to why you see boxes full of bagels and bananas at the end of a race.
During your training, you should calculate your sweat loss so you can make a better effort in r-ehydrating throughout your runs and to better understand how much your body really needs in order to maximize your performance. It’s important to calculate your specific sweat loss rate since this varies from person to person.
Marathon training will definitely test your body’s limits and it’s important to understand how your body is responding to training — including any weight gain — in order to make any necessary changes to maximize your performance for the day of the race.
- Chicago Area Runners Association
- The University of Chicago Medicine Orthopaedics Center
- Harvard Health Publications