Endurance athletes are always looking for ways to maximize their energy. Traditionally, the emphasis for fueling exercise has been on carbohydrates, and for good reason. Who hasn’t been in a race and felt the beast of a bonk about to take over when, with shaking hands, you ripped open a package of energy gel, squeezed, and, oh my gosh, power surge. You’re off!
Unlike carbohydrate, fat does not raise blood sugar, and for the most part, fat tends to get a bad rap in a culture of rising obesity rates. Why, then, you may ask, would an endurance athlete be concerned about getting enough fat in their daily diet? The answer to that question is not about more fat, rather, what kind?
Let’s take a look at some important fat facts – which types, how much, and their effect on performance. Last, a quick checklist for what to choose at the grocery store and create in the kitchen.
Fat: The Endless Fuel Supply
During exercise the body can draw on fat stores from several different sources. Responding to signals from hormones that act as traffic cops for energy, fat can be mobilized from white adipose tissue (your belly) or from fat stores within the muscle cells, called intramyocellular lipids. The OPEC of energy, fat reserves can provide even the bulkiest weightlifter or leanest triathlete with more than 40,000 calories of energy for fueling muscular contraction.
Many athletes, in the interest of maintaining ideal body weight or for health reasons, follow a diet than has less than the minimum recommended 20% calories from fat. A number of studies with endurance athletes have looked at manipulating total fat intake (irrespective of type of fat), and the results have not been necessarily positive. For example, in one study when healthy runners averaging 42 miles per week followed a 17%, 31% or 44% of total calories from fat diet, intakes of calcium, iron and zinc were below recommended levels on the low and moderate fat levels. Essential fatty acid intakes for females in the study were suboptimal on the low fat diet, and although extra carbohydrates were eaten on the low fat diet protocol, both female and male athletes reported feeling hungry.
Endurance-trained runners who follow a restricted fat diet (10% of calories) have also demonstrated an increase in fasting triglyceride levels, now considered an indicator of cardiovascular risk.
Not all nutrition experts are sold on the low fat/high carbohydrate diet regimen. As early as 1994, when the USDA Food Guide Pyramid was first introduced, researchers from Boston University Medical Center warned that the emphasis on carbohydrates – without specific recommendations to consume pasta and cereals derived from whole foods – would result in an increase in the number of people with essential fatty acid insufficiency (EFAI). Suboptimal levels of EFA’s promote generalized inflammation, a condition that ultimately contributes to cardiovascular disease risk – whether you’re a daily runner or not.
The Right Fats for Better Performance
Following a moderately high fat diet (30-35% of calories) does not appear to adversely affect performance, and it may actually improve your time to the finish line in events lasting over two hours.
Research conducted on migratory birds that are involved with ultra-distance aerobic exercise is an area of intense study to help understand factors that contribute to muscle fatigue. It’s no surprise that before a major flight migratory birds load up on plankton rich with high omega-3 fats. The change in diet is thought to aid in altering the fluidity of membranes, ultimately the key to modifying muscle performance by allowing for metabolic signals that affect energy metabolism.
Not all fats make the cell membrane more fluid; choosing the right type of fats is the key. Below are some guidelines to get you started.
Right-size Your Omega-6 and Saturated Fat Intake
Minimize the intake of saturated fat and omega-6 fat in order to improve the overall ratio of “good” fats – omega-3 to omega-6 fat and saturated fats. You can do this by using the following guidelines at the grocery store:
Hydrogenated fats – baked goods, check labels on candy, biscuit mixes, granola, breads, chips, pastries, and fast food restaurants. Look for labels that state “no trans fat”; avoid products with “hydrogenated fat” in the ingredient list.
Saturated fat – high fat dairy products: cheese, butter, half and half, cream cheese, whole and 2% milk; limit red meat (unless range fed) to twice a month, chicken skin, baked goods, mayonnaise.
Omega-6 fats – greatly decrease vegetable oils such as safflower, corn oils; limit soybean oil, which has low amounts of omega-3 fat to improve overall ratio of omega-3 to omega-6; limit processed baked goods.
ALA – alpha-linolenic acid sources, such as flaxseed, walnuts, pecans, wheat germ, pine nuts, and hemp. Range fed beef and chicken will also be high in ALA, unlike farm fed animals.
Olive oil, which contains low amounts of omega-6 fat, but is also low in omega-3 fats. Olive oil has high amounts of monounsaturated fats and therefore does not contribute substantially to the imbalance of omega-6 to omega-3 fats.
Natural EPA/DHA fat sources – wild salmon, albacore tuna (limit to 6 oz. per week due to mercury), mackerel, sardines, herring, halibut and haddock. Shellfish such as blue crab, shrimp, clam, mussels and oysters also contain omega-3’s. Include at least two servings of fatty fish per week; pregnant women and children should limit fish sources of omega-3 to once per week due to mercury contamination. Good sources of EFA’s include seeds, such as sunflower and pumpkin, nuts, such as walnuts and hazelnuts, wheatgerm, cold-pressed seed oils and most unrefined whole grain cereals. Functional Food sources of EPA/DHA and ALA fortified foods such as margarine, eggs, bread, yogurt, milk and cheese, and whole grain products.
Putting Healthy Fats on the Table
Adding healthy fats to your diet may be easier than saying “eicosanoid.” Love a hearty omelet after a Saturday workout? Try using high omega-3 eggs, low fat cheese, and a touch of smoked salmon. Add a side of toast made with a whole grain/flaxseed bread and you’re off to a good start. Grilled shrimp or grilled wild salmon make a great entrée choice for a Saturday night, and don’t forget to keep some smoked salmon and rye crisps around for a great post-workout snack.
Originally published Spring 2015 Issue
About the author
Donna Marlor is a Registered Dietitian, Registered Nurse, and has a Master’s degree in Education Psychology. She lives and plays in Marquette, MI and maintains a private practice in Sports Nutrition. Her philosophy is, “A good diet can change your life. Start today.” To contact Donna, visit www.DonnaMarlor.com.