Proactive Nutrition
Be Proactive rather than Reactive – Be in control
I seem to have a problem when it comes to controlling my eating schedule. Can you help me out?
Although it would be great if we only ate when we were hungry and stopped when we were full, most people struggle with daily “cravings,” emotional eating, and issues that cause us to use food as more than fuel. So, instead of following cravings or emotions, try sticking to an eating plan rather than waiting for sensations of hunger. Furthermore, don’t allow hunger to always be a call to action.
It is simply a good indication that your body is digesting fuel well and you can satisfy it at your next meal or snack. Eat when it’s time to eat, and then get on with your life. Don’t fixate on food, but simply prepare, eat well, and move on.
Please send us your questions for our Expert Sports Nutritionist, Kelli Jennings to “Ask the Sports Nutritionist“. Kelli Jennings is a Registered Dietitian with a passion for healthy eating, wellness, & sports nutrition. For more information go to www.apexnutritionllc.com.
I think it would be helpful to explain why serum insulin levels are important, and how they affect energy output or glucose metabolism while exercising. Some people might be under the impression that exercising in a condition where you have higher insulin levels might be exercising when you are more drowsy. One to two hours the peak time for glucose output from the small intestine after a meal, which provides ample energy for muscle consumption. Having another booster snack before the peak would line up another glucose surge for your activity in an hour.
Also, is this a good tactic for diabetics to use while training? Is this a good tactic for randoneers to use at the beginning of a century? I’ve heard that long endurance rides might best begin before a meal so as to activate the liver’s supply of glucogen first, so that your body has started kytosis, the method for tapping into your glycogen and fat stores.
It would also be useful to know what brings about a “bonk”, and if this happens when your dietary glucose runs low while your insulin runs high. Can this be avoided by activating your kytosic metabolism?
Hello and thank you for your comment! Here’s some more explanation on increased carbohydrates and insulin during exercise:
By eating a pre-ride meal a couple hours, or a pre-ride snack 30-90 minutes out, you provide your body with an efficient and usable fuel as you begin training. This ingestion of carbs increases the bodies output of insulin, as needed, which allows the blood sugar to enter cells and be converted into energy. As long as carbohydrates are continually ingested, during sessions longer than 60 minutes, the athlete should be able to maintain consistent blood sugars and energy output without becoming drowsy or low in blood sugar. Most people, who do not have hypoglycemic conditions or Diabetes, should not become dangerously low in blood sugar as there body’s typically maintain blood sugar levels by tapping into sugar stored in the liver, or breaking down fat or muscle and turning it into sugar – however, since this is a less efficient way to get blood sugar converted to energy, the athlete will likely feel a low in energy and not perform optimally (not dangerous, just not optimal).
The average time of peak blood sugar and peak insulin depends on the type and state of the food. For example, liquid simple carbs are digested and metabolized much quicker than a solid, high fiber meal. So, the type of food should be matched with the time it’s eaten (quick carbs closer to the time of exercise) – just as you said, eating a meal a couple hours out and then a quick-carb snack before working out allows the right “surge” of blood sugar.
With long-distance riding, such as with randonneuring, it’s a good idea to eat the pre-ride meal/snack, and then continue with 40-60 grams carbs and 16-32 oz. fluid per hour. If longer than 5 hours, I recommend also adding protein, up to 10-15 grams per hour. This can be accomplished with protein added to energy bars and/or fluids. Some athlete eat “real” foods rather than sports foods, but it’s just individual preference. I usually recommend sports foods as they reduce the risk of GI upset, and are generally more efficient to eat than regular foods. For rides >5 hours, it’s fine to add in more “real foods,” but not too much at any one time as they can cause extra work for digestion, which takes away from the energy available for cycling. I recommend simply adding in small amounts of these foods every 3-4 hours or so on long rides, and continuing with the sports foods used to accomplish the recommendations for carbs and protein per hour. On top of this, I recommend 400-700 mg sodium, 100-300 mg potassium, and 80-120 mg calcium, and 40-60 mg calcium per hour on long rides.
When I work with clients with insulin-dependent Diabetes, we work very closely and continuously monitor blood sugars. It depends on the control he/she normally has with blood sugars, the blood sugar reading before beginning a long exercise session and/or before the pre-ride meal/snack, and the intensity of the blood sugar. I cannot really make a generally statement for this situation. For non-insulin dependent Diabetes, it’s usually a good idea to eat a balanced meal (protein and moderately high fiber carbs) in a meal a couple hours out. Then, most do well with exercising and monitoring blood sugars during the workout. If the workout is longer than 60 minutes or high intensity, they too should consume quick-acting carbohydrates during the activity and continue to monitor blood sugars until they’ve formed a good plan to maintain target blood sugars for a given activity (then, they don’t have to monitor so much).
I recommend the pre-ride meal/snack rather than beginning in a fasting state – just experience personally and with clients – I see better performance with consistent intake of carbs rather than fasting/liver glycogen initially. It all does depend on the client’s goals – fat loss vs. optimal performance. Generally, I work with clients to encourage fat loss with Daily Nutrition, and optimal training with Training Nutrition.
‘Bonking’ can involve a lot of things. Sometimes dehydration. Sometimes too little blood sugar from lack of intake/too high insulin w/out carbs. Sometimes electrolyte imbalances, especially lack of sodium and/or potassium. Sometimes all of the above (they usually all go hand in hand with inadequate intake). I do not believe ketosis is a desirable state during long exercise sessions, as although it can provide energy, it is not efficient energy nor the best source for the brain (the brain prefers to operate on glucose). Also, it does not resolve any of the issues with electrolytes or dehydration.
There are many philosophies out there and very little conclusive, good, research! So, a lot of it is a combo of research, personal and professional experience and experience of colleagues. I hope this helps!
Kelli, RD
This is a remarkably informative answer, thanks!