Endurance Fueling

Endurance Fueling- What’s the Deal on High Fat, Low Carb Diets?

Since May is National Bike month we are highlighting recent fueling studies and bringing you our recommendation on nutrition for endurance athletes. Whether you are a distance cyclist or participating in an endurance activity (>1 hr), you always want to be properly nourished during training sessions and races. Note: The following studies are observing high-fat diets for performance athletes, not for weight loss

A new high fat, lower carbohydrate trend is growing in popularity for endurance athletes. The traditional diet prescription for endurance athletes is higher carb with a moderate fat intake. So why the flip flop?

The goal of this diet is to improve prolonged performance, delay fatigue and train your body to metabolically adapt to fat as a main source of energy. When carbohydrate intake is reduced, our bodies start to burn fat as it’s main source of energy and spare the remaining carbs as fuel for our brain. What studies have shown is that a high fat, low carb diet can be beneficial for some people during low-intensity exercise but does not actually improve performance capacity during high-intensity activity. During higher intensity exercise, fat-rich diets impair the rate that muscles can produce energy and thus limit work capacity. This happens because our muscles favor carbohydrates as fuel when they are working hard. This is when we need to keep training nutrition vs. race day nutrition in mind. During training, you may not be doing a much high-intensity activity and a high fat, low carb diet may be beneficial. However, during competition time you will probably be pushing into higher intensities when trying to pass a competitor or sprinting to the finish line. This is when carbohydrates become very important! We recommend modifying your diet to a mix of carbs and fats before and during race days or harder training sessions.

So bottom line – Even though high fat may “on trend” and ok with lower intensity training, we recommend making sure your diet to a mix of carbs and fats before and during race days or harder training sessions, so you will have the fuel you need to crash your competition when crossing the finish line! .

If you need coaching to help take your training and performance to the next level, schedule a consult with the Driven Sports Performance dietitian Serena, email her at serena@drivenaustin.com or schedule yourself on her calendar.

P.P.S. We talked about the importance of carbohydrates for optimal performance so what should a hard training day vs. light or rest day nutrition look like? Note: portion sizes will vary depending on athlete’s individual needs, this is just a sample. (Click on image to make it larger).

Sources:

“Building a Performance Plate.” NCAA. SportsRD.org. http://www.sportsrd.org/wpcontent/uploads/2015/01/Building_a_Performance_Plate_WEB.pdf.
Burke, Louise M. M. “Nutrition Strategies for the Marathon: Fuel for Training and Racing.” Sports medicine 37.4-5 (2007): 344-7.
Hawley JA, Leckey JJ. Carbohydrate Dependence During Prolonged, Intense Endurance Exercise. Sports Medicine (Auckland, N.z). 2015;45(Suppl 1):5-12. doi:10.1007/s40279-015-0400-1.
Hill, James Ph.D., Melby, Christopher Ph.D. “Exercise, Macronutrient Balance, and Body Weight Regulation.” Gatorade Sports Science Institute. SSE#72, Volume 12 (1999), Number 1.

 
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