The director of my local running club brought up the issue of losing weight while training for a marathon. He asked the general question to all of us whether or not we believed that a marathon was the proper training method to lose weight. Looking at the run club members, you might think so, since everyone is relatively thin and in good shape. Yes, many of us have areas that could use some work (who doesn’t?), but for the most part we are a fit bunch. And for most of us, training for a marathon might have changed our physique, but it was not a weight loss method for us. So, most of us said that no, marathon training probably wasn’t the best fitness method for weight loss (just think of the skinny fat men who complete marathons every weekend). On the other hand, almost everyone had a personal story (about them or a friend) where weight loss occurred when training for a 5k or 10k. A shorter race that requires less endurance? Why is that?
Anyone who has trained for a marathon probably knows the reasoning behind this. First, marathon training is not conducive to the common weight loss formula: decrease caloric intake and increase caloric burn. In marathon training, you are increasing your caloric burn, but your body requires more calories in order to even function, let alone perform at an optimal fitness level. That means that you require more than the average 1800-2000 calories/day diet touted on nutritional labels. In addition, endurance athletes (or distance runners) are more likely to experience “rebound hunger,” which is where they have an insatiable appetite post-fitness activity and end up negating that activity.
Second, when training for a marathon, you are building muscle mass. And, as you know, muscle weighs more than fat, so you might be heavier in pounds, but you are losing fat (or inches). So, definitely do not just use the scale as a gauge for your health. Also, since endurance athletes repeatedly deplete their body’s glycogen (or fuel), your body adapts by storing more glycogen – and the water that is used to assist with the glycogen breakdown – in order to help you avoid “hitting the wall.” This also translates to “weight gain” as judged by a standard scale.
Conversely, when training for a 5k or 10k, your body doesn’t demand as many calories and doesn’t store as much glycogen (and water), so it is easier to lose “weight” or pounds.
Back to the dicussion from run club, there were a few individuals who mentioned that they notice a weight loss in the weeks after a marathon, when they are recovering with less miles and more circuit training. According to Jenny Hadfield in Ask Coach Jenny on Runner’s World, this commonly occurs because your body continues to burn calories at the same level as when you were training for a marathon, but yet you have a lessened appetite and are consuming fewer calories. Also, without continued use of your muscles at that same level, your muscle mass will begin to decrease, causing a drop in pounds.
A good place to visit regarding this issue is the Nutrition and Weightloss Section of Runner’s World online.
So, marathoners, what do you think? Would you recommend marathon training to someone trying to lose weight? What is your experience?