What do football player Jay Cutler, baseball player Adam Duvell, golfer Scott Verplank, and hockey player Cory Conacher have in common?
All of these professional athletes have diabetes.
And while we may not all be quite as athletically gifted as they are, regular physical activity — whether recreational or competitive — is an important aspect ofhd diabetes self-care. A minimum of 150 minutes of physical activity a week is recommended for most people with diabetes, with an emphasis on not only the cardiovascular and strength training perks but also the positive benefits of physical activity on blood glucose management. Understanding how to best manage blood glucose during physical activity, especially during strenuous and long workouts, often requires knowledge about your blood glucose patterns, diabetes medications and the role food plays in your workouts.
Managing blood glucose during exercise
Although physical activity generally is a good thing, it also can be a challenge when it comes to blood glucose management, especially for those with Type 1 diabetes. Physical activity lowers blood glucose by increasing the uptake of glucose by the muscles during exercise.
Additionally, exercise can increase insulin sensitivity for several hours after, which can increase the risk of hypoglycemia, which in turn can decrease performance and lead to serious medical issues. Even moderate physical activity can cause a rapid decrease in blood glucose, increasing the risk of hypoglycemia both during and after exercise. In those who don’t have diabetes, starting physical activity typically is followed by a drop in insulin secretion, a mechanism the body has developed to help avoid hypoglycemia during exercise.
But people with diabetes, especially those taking insulin, ideally should try to mimic that by working with their health-care providers on strategies to adjust insulin and/or carbohydrate intake for physical activity, especially for long, intense training regimens. The adjustments required depend on four factors of your exercise: type, duration, intensity, and frequency. Finding the right balance of insulin and carbohydrate can help reduce the risk of hypoglycemia during exercise. It is important to always be prepared and have fast-acting sources of carbohydrate on hand in case you need to treat a hypoglycemic event.
Exercise and blood glucose patterns
Hypoglycemia isn’t the only challenge; hyperglycemia can occur from withholding insulin, eating too much carbohydrate, or participating in intense physical activity. Those who are intensely active will notice that immediately after exercise their blood glucose levels may be elevated. This occurs for two reasons: At a certain point, exercise causes the body to break down fat, and elevated lipid oxidation can suppress carbohydrate metabolism; and exercise causes hormones such as epinephrine to break down and move glucose from the liver into the bloodstream to supply the working muscle with energy for up to two hours post-exercise, which can contribute to increased blood glucose levels.
“Restoring hormone balance may take some time, especially after intense exercise. Ultimately, exercise will help lower blood glucose as insulin sensitivity is improved and glucose is cleared from the blood,” said Laurel Wentz, PhD, RD, CSSD, assistant professor in nutrition science at East Carolina University. A general knowledge and understanding of one’s own response to exercise intensity is important to determine the proper amounts of insulin and carbohydrate intake. Frequent monitoring or use of a continuous glucose monitor (CGM) can provide feedback to ensure better understanding of blood glucose patterns and develop a strategy for managing those patterns.
Finding the best fuel
Fueling for physical activity is an important component of achieving peak performance during exercise. Nutrition goals may be personalized, depending on various factors including training schedule, performance goals, food preferences, weight or body composition goals, training climate, and blood glucose responses during workout sessions. Recreational and competitive athletes may want to ask a registered dietitian (RD) who is a board certified specialist in sports dietetics (CSSD) to customize a plan to meet unique requirements for fueling training and competition needs. This professional can help set short-term and long-term goals to help effectively improve performance, increase muscle mass, or reduce body fat/weight.
Nancy Clark, MS, RD, CSSD, author of Nancy Clark’s Sports Nutrition Guidebook, has worked with both professional and recreational athletes in her private nutrition practice in Boston. “Both food choices and the timing of food are important,” she said. “You wouldn’t drive a car with an empty tank, and active individuals [with and without diabetes] should consider how to make the best choices to fuel their workouts properly.”
Sports nutrition myths dispelled
Sports nutrition expert Nancy Clark MS, RD, CSSD shares the facts on three popular myths about eating right to enhance sports performance.
Myth #1: Carbohydrates make you gain weight.
“A calorie imbalance — i.e., too many calories being consumed and not enough calories being burned through activity — contribute to excess weight, including extra fat, not carbohydrates alone,” said Clark. Carbohydrates include a multitude of healthy foods, and including them as part of a balanced diet can enhance your muscles’ ability to get the most out of a workout. Carbohydrates also can play an important role in reducing the risk of hypoglycemia during physical activity.
Myth #2: You need more protein to build more muscle.
“Exercise builds muscle, and carbohydrates fuel the workout that builds the muscle,” stressed Clark. Without the proper training regimen and a balanced healthy diet, it’s difficult to build more muscle. Simply adding more protein to your diet through shakes or food only adds additional calories and not necessarily the increased muscle mass you are seeking.
Myth #3: Sports products are better than real food.
Clark says there is nothing particularly advantageous about many popular sports products on the market. Some of them are very highly processed and are not necessarily better choices than healthy whole foods. Clark suggests taking a whole-foods-first approach, building healthy snacks and meals with simple ingredients from your kitchen — grabbing a Greek yogurt and topping it with granola or making a few peanut butter crackers.
The three macronutrients — carbohydrates, protein, and fat — all are important components of a well-balanced diet for active individuals. Each has a role in providing the body with important nutrients to prepare for, fuel, and recover from workouts.
Carbohydrates (or starches and sugars) provide key fuel for the brain and central nervous system and are an important factor in supporting workouts. Sources of carbohydrate include grains/starches; milk/yogurt; vegetables, especially starchy vegetables such as beans, peas, corn, and potatoes; fruit; and any food with added sugar. The amount of carbohydrate needed depends on an individual’s weight, and the timing of intake depends on the workout routine and, for individuals with diabetes, blood glucose levels before, during, and after exercise.
Protein plays an important role in repairing and remodeling muscles and also helps enhance structural changes in non-muscle tissues such as tendons and bones. Protein needs depend on body size and physical activity needs; however, according to current research, they generally range from 0.8–1.2 g/kg/day for the average, moderately active person. They may be higher for recreational and competitive athletes, ranging from 1.2–2.0g/kg/day. Good options for protein include both animal and plant-based sources including beef, poultry, fish, beans, milk, yogurt, cheese, and nuts and seeds.
Fat also is a necessary and important component of a healthy diet. Fat is a source of energy and an important part of cell membranes, and also it helps the body absorb important fat-soluble vitamins such as Vitamin A, D, E, and K. Include better-for-you sources of fat in your diet — foods rich in monounsaturated and polyunsaturated fats including avocado, olive oil, salmon, nuts, and seeds. The Dietary Guidelines for Americans 2015–2020 suggest saturated fats, found in butter, cream, and lard, be limited to less than 10% of your total daily calorie intake. Some fat is good, but too much can cause issues with calorie balance and cramping during workouts. Wentz suggests avoiding extremely high-fat meals and making lower-fat choices. “Fat is the slowest nutrient to digest and will stay in the intestinal tract longer, which can cause cramps.”
Timing is everything
When should you eat snacks and meals while working out or training for an event? The answer can vary depending on personal goals and the intensity and frequency of the workout schedule. Here are some general tips when it comes to fueling up for fitness.
Staying well hydrated is important for overall health and contributes to exercise performance. The amount of fluid needed depends on body weight, climate, and sweat rate. Monitoring the color of urine, for most healthy individuals, can be a good way to elevate hydration status. The goal is to avoid dark and concentrated urine and aim for urine that is pale yellow.
Wentz suggests these general hydration guidelines.
Before activity: 2–4 hours before activity consume 12–16 ounces of fluid and ensure urine is pale yellow.
During activity: Start by consuming 16 ounces every 30–60 minutes. Competitive athletes may weigh themselves before and after an event to assess hydration status. Said Wentz, “You know you are adequately hydrating if you don’t lose more than 2% of your body weight [i.e., 4 pounds for someone who weighs 200 pounds before exercise]”.
After activity: Consume 16 ounces for every pound lost during exercise, or drink until urine is clear.
Timing of meals and snacks
Both Wentz and Clark emphasize the importance of timing meals and snacks for fueling your workouts.
Before a workout: If it has been more than 3–4 hours since your last meal, consider eating a small snack 30–60 minutes before working out. Clark suggests a 100–300 calorie snack that contains carbohydrate and a small amount of protein and is easily digested. Good pre-workout snacks include an apple with 2 tablespoons of peanut butter, 4 to 5 whole grain crackers with 1 ounce of cheese, or 1/4 cup of granola with low-fat Greek yogurt.
After a workout: Do you need a recovery snack or meal? The answer depends on the intensity, duration, and timing of the next workout. Said Wentz, “Recovery nutrition is especially important if athletes completed endurance exercise for longer than one hour, engaged in intense resistance training, or have a second workout scheduled for the day. Otherwise, recovery nutrition can be paired with a meal to maximize exercise recovery while maintain weight and blood glucose.” She suggests eating foods with a moderate amount of protein and carbohydrates. Her top three favorite recovery options are Greek yogurt with berries, oatmeal with walnuts and raisins, and half a bagel or two slices of whole grain toast with two eggs and one slice of cheese.
Regardless of whether you are a recreational or seasoned athlete, developing a better understanding of how fitness affects your diabetes management is important. Keeping the fun in fitness for individuals with diabetes often means planning ahead. Monitoring blood glucose patterns, prepping healthy options for snacks and meals, and being prepared in case of a hypoglycemic event are critical parts of self-care. But don’t let that stop you from participating in the activities you love.
As Bo Jackson once said, “Set your goals high, and don’t stop until you get there.”