Prior to the Western States 100, the race director held a conference with some of the best doctors and scientists studying endurance athletes. You can read the report by clicking on the source link, but below are some of the more interesting findings presented.
- Drs. Volek and Phinney are in the process of reviewing findings from a study they did comparing high fat endurance athletes to high carbohydrate endurance athletes. Little information has been released yet, but they did share some of their preliminary findings. Ultrarunners with higher fat do rely more on internal fat stores during exercise. This conserves glycogen for longer periods and requires less carbohydrate intake to fuel exercise. To get these results the athletes must eat higher amounts of fat, not protein. If fat is not increased and carbohydrates are decreased, performance will suffer. Additional findings: less insulin resistance, oxidative damage and GI damage in higher fat athletes.
- GI distress is the primary reason athletes do not complete ultra endurance events. During one study, the athletes who ate more fat earlier during the race were less likely to develop GI distress symptoms, but the researcher was not sure if this was simply an association versus a correlation. More research would need to be done to draw a conclusion.
- Sodium supplementation had no effect on blood sodium levels at the end of the race. Runners who consumed excessive sodium capsules (25-60 during an ultra running event) gained weight during the race and are at risk for increased blood pressure. Runners prone to high blood pressure or kidney issues should use caution when supplementing with sodium.
- Hyponatremia (low levels of sodium in the blood) is caused by drinking more than indicated by thirst, excessive sweating, heat and increase secretion of anti-diuretic hormone (ADH) from the stress of excessive exercise.
- There are cardiac differences in ultra runners versus sedentary people. The heart does some remodeling after ultra events, mostly on the right side, but still functions normally. This is an important point as some physicians may think there is an issue with the heart if they are not familiar with remodeling that can happen with ultrarunners. If you are an endurance athlete and have concerns about your heart function in response to years of endurance exercise, I encourage you to consult a physician that regularly works with endurance athletes.
These are some of the key points that I found interesting. There is additional information on the barefoot running controversy, improving running performance, kidney injury and observations on medical needs during an endurance event. Please read the summary report for more information.