SCIENCE FRIDAY: TIMING CARBOHYDRATE-FASTING TO IMPROVE PERFORMANCE

Near Baltimore Harbor. Taken by PKSenagore November 5, 2018. All rights reserved.

IMPROVED RESULTS MAY  NOT BE A MATTER OF QUANTITY BUT OF TIMING IN RELATION TO TRAINING! Matt Fitzgerald provides runners and other athletes with an alternative to high fat-low carbohydrate (HPLC) diets that promise to burn fat to increase endurance, but leave them feeling “lousy” without performance gains.
 
In his article “An Easier Way to Become a Better Fat Burner” for running.competitor.com
Fitzgerald reviews a recent scientific study which showed that it’s possible to teach muscles to burn fat as a fuel, without limiting the total amount of dietary carbohydrates (CHO).  As a matter of fact, the protocol tested by French National Institute of Sport scientists was HIGH in CHO. The difference between the experimental and the control group diets in the study involved the TIMING of CHO intake in relation to training*. 
 
The experimental group of athletes in the study trained with high intensity, late in the day, 4 times a week, after which they ate a dinner with ZERO-CHO.  The following morning the athletes completed a low-intensity workout before breakfast in a fasted-CHO state. On these 4 days, all the CHO eaten by the experimental group was consumed at 2 meals (breakfast and lunch). The rest of the week the experimental group’s diet matched that of the controls, who were not carb-fasted but who followed the same training regimen.
 
Fitzgerald describes the study results: only the athletes who were carb-fasted in relation to training exercise showed significant performance improvement in cycling tests and running time trials. He then goes on to suggest a practical, much less extreme nutrition regimen by which athletes may be able to achieve nearly the same results as the French study.   Elite athletes already do this, he explains.  Fitzgerald thinks the lifestyle of Kenyan runners, considered among the best in the world, lends itself naturally to this type of training. 
 
It is possible that changing the timing of dietary CHO intake in relation to training will result in similar favorable performance improvements in recreational athletes. The reasonable course suggested by Matt Fitzgerald may be worth trying for those hoping to avoid problems encountered with extreme high-fat, low carb plans.  It’s one I’ve followed for decades because of a personal preference to run on a nearly empty stomach. It’s not clear whether my performance has improved, but this habit has allowed me to happily anticipate, complete, and enjoy almost daily early morning workouts.
 
The sentiment expressed by Fitzgerald in his article that I most respect is reflected in his statement: “I don’t like to see athletes or anyone else eat no-carb meals very often. The only natural foods that contain zero carbohydrate are meat, fish, and eggs. An all-meat/fish/egg dinner is not exactly nutritionally balanced.”
 
Extremes are difficult to maintain long term, and his might be a plan that can provide nutitional balance and good results.
 
RUN & MOVE HAPPY!
 
https://running.competitor.com/2018/11/nutrition/an-easier-way-to-become-a-better-fat-burner_146746
 
*NOTE: The broader sport research community refers to CHO intake timing as “carbohydrate periodization” and going to sleep after high intensity training with CHO restriction as a “sleep-low strategy”.  If you wish to search the literature for more information, these are helpful search terms.
 
https://www.ncbi.nlm.nih.gov/pubmed/26741119
Enhanced Endurance Performance by Periodization of Carbohydrate Intake: "Sleep Low" Strategy. Marquet LA, Brisswalter J, Louis J, Tiollier E, Burke LM, Hawley JA, Hausswirth C.