Written by: Pip Taylor
Pip Taylor explains how to manage your appetite after long workokuts.
Q: Any workout I do that lasts more than an hour and a half leaves me abolutely starving. I did Ironman 70.3 Austin last October and just could not get by on gels and sports drinks alone. I got to the run and consumed every pretzel and Pringle I could find. If someone had offered me a cheeseburger, I would have grabbed that as well. It seems like hypoglycemia, but I have been tested for that and the result was negative. I just can’t seem to get enough food. Any suggestions?
Chagrin Falls, Ohio
A: Triathlon training and racing will certainly make you hungry. I would think that all athletes know the feeling of coming in from a long training session and feeling as though they could down enough food to feed a family of four. And to some degree, this hunger is caused by the large amounts of energy expended during hard training sessions. However, hunger is also a very unreliable indicator of energy needs, and the two are often not in sync. Without knowing a lot about you, my best guess is that you don’t take in enough fuel before workouts or races. (See my previous article on fueling up for a half-Ironman in the Feb. 2008 issue of Triathlete.)
It would also be helpful to know whether you are just really hungry or you feel as though you cannot physically go on any longer and that your performance is compromised by low energy levels. If you just feel a bit empty in the stomach, try consuming some solid foods during the race and foods and drinks that contain small amounts of protein. This might help you feel more sated. The other thing to consider is sodium. Craving high-salt foods may be an indication that your salt levels are depleted. This is more likely to occur during hotter events (such as Longhorn), in less well-trained athletes and those who are not accustomed to the heat.
Genetics, environment, habits and even psychology play important roles in the neurochemical, metabolic and sensory pathways of appetite and its regulation. However, it is a complex phenomenon that is far from being completely understood. Significant changes in appetite or weight can be symptoms of underlying medical conditions and are worth investigating with your doctor to see if this is the case. However, I am assuming that you have no medical issues or alarming changes in weight or exercise capability—just extreme hunger.
Fat and glycogen are your body’s main fuel sources during exercise (with protein making a smaller but significant contribution). While fat stores are effectively limitless, glycogen is not. As muscle glycogen is depleted, blood glucose levels drop, resulting in feelings of fatigue, intense hunger and dizziness—the classic signs of bonking. Generally, assuming you are well-fueled going into a training session or race, you should have enough stored glycogen to easily get through 90 minutes. However, if you seem to be hitting the wall prematurely, then it is likely you have not eaten enough before the race and may need to reconsider your fueling strategy both the day before and on race morning. For events lasting more than 90 minutes, it is essential to consume sports drinks and gels during the race at a rate that will maintain blood glucose levels and delay fatigue (30 to 60g carbohydrate per hour).
The amount of glycogen your body stores, and hence the amount of carbohydrate you need to take in during a race, also varies among people. Highly trained individuals store more glycogen and also utilize fat more efficiently. Hence, an elite athlete who has trained and raced for many years will probably need to take in less fuel during a race than someone new to the sport or just stepping up to a longer distance. Your body adapts to what it comes to see as normal stresses.
Speed or intensity of effort will also affect your appetite. For most individuals, a really hard training session or race will actually suppress hunger, at least temporarily. It will return strongly later, but that temporary suppression of appetite can make refueling during or immediately after a race or hard workout difficult. This is probably due to elevated body temperature, increased lactate production and a shunting of blood away from the digestive tract to working muscles and to the skin for cooling. The effect of body temperature on appetite may explain why athletes are typically ravenous after swimming in cooler water and not hungry at all while cycling or running in a hot and humid climate.
The type of exercise you’re doing, physical or mental stresses, and even altitude can affect your appetite. It is because appetite has so many influences that athletes often have to plan their diets, getting the quantity and quality of food they need when they need it rather than being led by unreliable feelings of hunger. This can apply to both training and racing situations. So develop a plan and stick to it! Ensure that the day before a race (particularly a half-Ironman or longer) you are fueled up, never skip your pre-race breakfast and determine exactly when and how much you need to be eating at each stage of the race. These needs are different for everyone, but aim for 30 to 60 grams of carbohydrate every hour (from both foods and drinks). When you have that plan in place, take a little extra with you on the bike just in case and don’t try anything new on race day.