With the longer days and early sunrises, early morning rides are a scheduling reality that need to fit around work and other life obligations. The alarm sounds, you roll out of bed, and the last thing you can think about is eating or drinking, as there is just no time. Besides, you want to adjust the engine valves to favor more fat burning, and setting out on the bike with no food should do just that. Maybe that is an option — but what, when, and how much you should eat for early morning training really depends on the nature of your training ride, your goals for that training ride, and appreciating just where your fuel gauge reading falls that particular morning.
As all cyclists know, muscle glycogen is an important fuel source during most any ride, whether easy or more intense and depending on your training intensity, muscle glycogen can become significantly depleted in 75 to 90 minutes.
Depending on that day’s previous training and the extent of fuel debt you incurred, and how well you recovered from your fuel debt with proper diet in the time window available, you may or may not even have high levels of muscle glycogen when you set out on your bike at daybreak. For example, if you regularly train early in the morning, you likely had a full 24 hours to replenish muscle glycogen stores, starting with a well-earned recovery breakfast immediately after the ride and steadily replenishing muscle glycogen with regular meals and snacks during the remainder of the day.
However, training schedules are often a mix and match of training times, and nutritional recovery time may be much shorter than 24 hours, and often less than 12 hours. Suppose you trained the previous evening, had a late post-ride dinner and maybe even a late evening snack, and then had to train again the next morning? Your muscle glycogen replenishment likely did not return to full levels before your early morning ride.
But no matter what time you train, or at what intensity, blood glucose supplies carbohydrate fuel during all types of training rides, and supplies glucose to muscles running low on glycogen, and is the major fuel source for both your brain and central nervous system during exercise and at rest.
Liver stores and blood glucose
Liver glycogen is the source of blood glucose, making it an important fuel depot. Liver glycogen operates under a different set of checks and balances than muscle glycogen, and fluctuates throughout the day. Blood glucose levels peak about an hour after eating and return to the fasting range about two hours after a meal. The liver responds to fasting blood glucose levels by breaking down its glycogen stores and sending glucose into the bloodstream. This scenario plays out several times during the day as you regularly consume meals and snacks.
However, if you fast for 12 hours or so, such as when you sleep, your liver still needs to maintain blood glucose levels. When you wake up in the morning, your liver glycogen stores are only about one-fourth to one-third full, at about 80 grams worth of carbohydrate. Your clever liver can also make glucose from amino acids, lactate, and a fat called glycerol. At anytime during both fasting and exercise, you have about 20 grams of glucose circulating in your bloodstream, an amount that can provide about 10 minute’s worth of fuel on the bike.
Fueling up for the ride
Nutritional strategies designed to deliver an optimal amount of fuel during your early morning rides can delay the onset of fuel depletion, sustaining your scheduled workout at the desired level of completion, particularly for tougher rides.
Obviously digestion and timing are two important considerations in the early morning hours. The following snacks could be consumed about one hour before training. Experiment to see what works best for your tolerances and schedule.
•Cereal bar or energy bar
•Liquid meal supplement
•Cereal with milk and fruit
•Yogurt with fruit
•Toast with jam
There is some old controversy leftover from the 1980’s regarding the ingestion of carbohydrate 45 to 60 minutes before exercise. Based on some early data, there was some concern that this timing of carbohydrate intake could result in hypoglycemia, or a decrease in blood glucose levels during exercise, producing negative symptoms and performance results. In fact, many studies have confirmed that consuming carbohydrates in the hour before exercise does not hurt performance and can actually help performance. Even though blood glucose levels can drop early in training, it corrects itself to normal levels, and most athletes have no adverse symptoms. A small number of cyclists however, may experience some hypoglycemia and some negative effects such as fatigue, shakiness, and dizziness.
If you are concerned that you may be a carbohydrate sensitive cyclist in the hour prior to training, you can try out a few strategies. Aim for a pre-exercise snack that provides 70 grams of carbohydrate. Check labels of foods and supplements and add up the total grams. Many snacks consumed in the hour before training often only provide 50 grams of carbohydrate or even less. The higher carbohydrate intake can compensate for the higher rate of glucose use, still leaving you with a net gain in carbohydrate availability. You can also consume a sports drink as soon as the ride starts as this helps to maintain blood glucose levels.
If you truly only have 15 to 30 minutes of awake time before setting out, you can also follow a few simple strategies. Start drinking a sports drink in the 15 minutes before setting out. This will help to raise and maintain blood glucose levels and is easily tolerated. You can even down a gel in the minutes before setting out to boost blood glucose. Keep in mind that you also need to hydrate when you wake up and should drink fluids regularly during training. A sports drink of course also provides the needed carbohydrate.
What if you decide to go out for a quick spin on just water and no pre-ride fuel — will you bonk? Probably not, because of the nature of that ride. Will you burn a greater percentage of fat? Yes, exercising in the fasted state (about eight hours since the last meal) does result in a greater proportion of fat being used as the exercise fuel when compared to doing the same ride following a carbohydrate containing snack. But, if you have to ride harder and longer, you should consume carbohydrate before and during training so that you can complete the ride. Overall, this results in more calories burned, which results in more fat loss. If you do want to burn more fat during a training session, tread carefully. You likely will have a greater tolerance for training on only water during lower intensity and shorter rides.
Monique Ryan, MS, RD, LDN is a nationally recognized nutritionist with over twenty-four years of experience and is owner of Personal Nutrition Designs, a Chicago based nutrition consulting company that provides nutrition programs for endurance athletes across North America (www.moniqueryan.com).