Food before Morning Workouts?
“Should I eat before I exercise in the morning?” This is a question I have been asked many times in the last 27 years working as a trainer. There seem to be two major schools of thought on the answer. The first comes from many medical and nutritional practitioners. It is that one should eat something in the morning before working out to stabilize blood sugar levels to avoid dizziness or weakness during the workout session. The second school of thought comes from some scientists who are researching energy usage during exercise in a fasted state. There are a number of fitness trainers who have gleaned to the results of such research, believing that there is enough evidence to advise people to exercise on an empty stomach because the body will more readily burn fat as fuel.
Both schools of thought have their pros and cons, but how the question is answered depends on the goals and health of the individual. What works for one person may not work for another. The best way to answer the question is to look at some of the research as well as the medical recommendations available to us and explore an avenue that seems most appropriate for the individual.
The Mayo Clinic staff published recommendations for eating and exercise performance here. Their overall view is to wake up with enough time prior to exercising so one can eat breakfast. This approach is thought to stabilize blood sugar levels and help one avoid feeling tired during the workout. Food choice as well as quantity is crucial because too much or the wrong kind of food can also make one tired.
A large meal of 600–1,000 calories or something sugary and high in fat like a donut would definitely sabotage a morning workout. A moderate breakfast of an egg and one piece of whole wheat toast or a bowl of oatmeal totaling 200–300 calories one to two hours prior to exercise would give a person adequate energy without causing abdominal or intestinal distress. Keep in mind, too, that foods that are high in fat, fiber and protein can contribute to gastrointestinal distress if consumed too close to or during workouts.
Nancy Clark’s Sports Nutrition Guidebook recommends eating foods low or moderate on the glycemic index prior to endurance exercise. Energy from these foods lasts longer in the bloodstream and can help sustain a 90–120 minute workout, possibly eliminating the need to ingest carbohydrates while training. Bran cereal, brown rice, apples and bananas are just a few of the foods considered low to moderate on the GI. However, the GI is outdated as it does not account for typical serving sizes. A better guide is the glycemic load. The glycemic load basically takes more realistic portion sizes into account, which in some cases can change the low/moderate or high ranking. Compare your food choices with this chart that lists both glycemic index and glycemic load. This scale is also supported by the American Diabetes Association, which brings up another point: Certainly those with Type I Diabetes must test blood sugar levels before and after exercise in order to regulate themselves. According to the American College of Sports Medicine’s guidelines for diabetics, hypoglycemia is one of the most common issues when exercising. Obviously for this population, exercising in a fasted state would be contraindicated, so the recommendations above from both the Mayo Clinic and Nancy Clark, RD would apply to diabetics as well as to the general population.
The theory behind exercising on an empty stomach is that one will more readily burn fat and spare glycogen because one is already in a hypoglycemic state. Research dates back at least 20 years inquiring into this theory. While findings are promising, most of the trials use a small number of subjects. It is difficult for many reasons to do long-term trials on large cross sections of population. Getting large groups of people to commit to long-term studies is difficult and expensive. Control of the subjects’ activities and eating habits, though ideal, is limited. So when studies are done, it is usually with a small group of people from a particular population. Keeping all that in mind, here are several studies that report a mixture of results for exercising in a fasted state.
A study published by Borer et al. (2009) utilized an untold number of healthy post-menopausal women who exercised for two hours on a treadmill at a moderate pace twice a day. The women exercised in a fasted state as well as after a meal. Blood was drawn and a number of elements were tested. One of the conclusions was that exercise in a fasted state caused post-exercise ketosis, while exercising after a meal did not. That is a marker that fat was used for fuel during exercise and for recovery due to the reduced availability of carbohydrates.
The next study by Bouhlel et al. (2006) studied nine trained male rugby players during Ramadan, a month-long fast practiced by Muslims when no food is eaten during daylight hours, only at night. The average age of the players was 19 years old. Oxygen usage in the men was tested prior to the fast, during the first week and during the fourth week while they trained at low to moderate intensity on a bike. Results of the study indicated that fat utilization during exercise increased over the month-long period of Ramadan. These athletes did lose both body mass (muscle) and body fat over the month-long fast due to the reduction of calories. One of the concerns some trainers have regarding exercise on an empty stomach is that the body might also utilize muscle protein for fuel during workouts and it is muscle that we work so hard to obtain. People who are restricting calories may want to consider this factor.
The third study by Dohm, G. et al. (1986) utilized nine male adults and tested them while running after a fed state and a 24-hour fasted state to decipher what substrates (types of energy) were present in the blood. It was found that in the fasted state there were significantly higher levels of free fatty acids (fat as fuel) while blood glucose remained level because the muscles were sparing their glycogen and not burning it.
Available studies show promising results for exercising on an empty stomach for the purpose of achieving the greatest fat burn. However, what is not addressed in the studies is meal timing and following a meal pattern that contributes to decreasing obsession with food and reducing the urge to binge. All too often we encounter the fellow Spinning enthusiasts who don’t eat before the morning Spinning class. They intend to eat breakfast, but end up not eating until lunch. They incorrectly think that since they are starving all morning they will see accelerated weight loss. Unfortunately, all too often this results in the uncontrollable urge to binge at night, which leads to being either too full to eat in the morning or self-punishment. This drives a never-ending battle between guilt, starvation, bingeing and disappointment in results (in both weight and performance).
Advice from Registered Dietitian & Spinning MI Jennifer Ward:
- First and foremost—to lose fat, understand that you need to create a calorie deficit. If you burn more fat during an exercise session, but consume too many calories, weight loss or fat loss will not happen.
- Eat a small snack before your morning workout (1/2 banana, yogurt, a whole grain piece of toast). Not only will this stabilize blood sugar levels, but it will enhance the ability to focus on the exercise session rather than hunger.
- Remember that eating can enhance endurance and performance, which will lead to a higher quality workout, better calorie burn and more potential weight loss.
- Make sure to eat breakfast shortly after your workout. It is well documented that carbohydrates consumed within 30 minutes after an exercise session are most efficiently used to replenish glycogen stores.
- Trust that eating early in the day will enhance the ability to control hunger and make better food choices throughout the day, which will potentially contribute to better weight loss/fat loss, performance and being at peace with food.
Borer, Katarina et al., Two bouts of exercise before meals, but not after meals, lower fasting blood glucose. Medicine & Science in Sports & Exercise. Vol. 41 (8). Aug. 2009, 1606-1614
Bouhel, E. et al., Effect of Ramadan fasting on fuel oxidation during exercise in trained male rugby players. Diabetes & Metabolism. Vol. 32 (6) Dec. 2006. 617-624
Dohm, G. et al., Metabolic responses to exercise after fasting. Journal of Applied Physiology, Vol 61, Issue 4 1363-1368