Back in December I wrote here about the KISS principle. In that post I was focused on workout design. Lately, my podcast channels have been filled with dietary advice for endurance athletes. But there is a problem; an abundance of complexity and what seems like contradictions. Echos of my last post about training apps. Let's take a closer look.
One dietary approach is so popular it does not need a reference: fasted training, a.k.a. training low. At the minimal end it involves doing a morning workout before breakfast. At the extreme end it means eating a light, low carb dinner, no breakfast, and just a little after the workout. Why would you do this? No time to eat and run? No, the goal is not to save time. There is research that suggests - note I say “suggests” - that training at low intensity in a calorie deficient state (low blood sugar) will force your muscles to burn more fat and less carbohydrate. When done repeatedly over time the muscles will learn to favor fat as a fuel source, thus extending the time an endurance athlete can perform before bonking.
At least one expert, Dr. Stacy Sims, author of “Roar,” advises women to never train low. I recently heard someone claim that fasted training, a.k.a. fuel for the work required, only works for men, if at all, because women’s metabolism does not react well to energy deficiency. I guess we can consider that agreeing with Dr. Sims.
It is hard to talk about eating without talking about weight. Many athletes of all genders struggle to hit a weight goal. Sadly, and all too often, this is driven by comments from their coaches. Some of the best comments I have encountered concerning weight were from Chef Alan Murchison on Michael Eriksson’s podcast, “That Triathlon Show,” episode 366.
In the same episode Murchison talks about a simple version of fuel for the work required, where he categorizes training days as easy, moderate, and hard, with suggestions on how to fuel for them.
One important distinction between fasted training and fuel for the work required is how the athlete starts a workout. To put it simply, fasted training involves training on an empty stomach, whereas fuel for the work required is more about adjusting the calorie intake during and after exercise in order to meet the body’s demands.
Some of the best parts of the Murchison interview are his comments about monitoring weight, and monitoring food intake. To sum it up, don't be obsessed with your weight, eat good food in appropriate amounts, and leave the portion weighing to the elites looking for that 0.1% marginal gain. Strive to get 80% of your eating “good food,” and don’t kick yourself for enjoying an occasional hamburger.
My advice? Be kind to your body, and be kind to yourself. If you aren’t enjoying your mealtime, you are doing it wrong.
For more on fuel for the work required, see this article in Cycling Weekly, and the article that started it all, "Fuel for the Work Required: A Theoretical Framework for Carbohydrate Periodization and the Glycogen Threshold Hypothesis."
For women especially, check out Dr. Stacy Sims' book “Roar.” Chapter five is titled “Making Weight.” In it she writes, “Time your intake. Don’t go into an exercise session totally fasted, especially in the morning, when cortisol levels are at their highest …” And, “Please, please, don’t do intermittent fasting. Fasting drives cortisol up, creating an elevated baseline of cortisol, which promotes fat storage.”
Here is Dr. Stacy Sims on the TrainingPeaks CoachCast, episode 22, on fasted training:
If you do fasted training, you increase your reliance on free fatty acids. Sure you do because your body’s in the stress state, it needs metabolism. But, you look at the performance outcomes, the results are equivocal. When you look at the health outcomes, it’s an no-goer and people don’t talk about that.
Finally, that delightful interview with Chef Alan Murchison. That Triathlon Show, episode 366. I recommend listening to the entire interview, in spite of what he says about free advice from social media!
To sum up, there is a lot of information out there on what to eat and when. Shun the crazy stuff. Avoid diet programs that target normal people. Eat to be strong, not thin.