How long to fast before STA?

[osksa]

Eric, I read you report. Very interesting! However, as you note, not very practical. So my conclusions so far is: 1-3 days of fast: Worse results according to the study above. 21 days is good, but too taxing on the body. So the best results for anyone that does not want to fast for 21 days is less than 1 day. Comments?

 

[MarcinB]

There is another option - caloric restriction (e.g. by 50%). It puts less stress on the body, however, it has to be maintained for at least a month or two for the full effect to develop.

 

[efattah]

Eric, I read you report. Very interesting! However, as you note, not very practical. So my conclusions so far is: 1-3 days of fast: Worse results according to the study above. 21 days is good, but too taxing on the body. So the best results for anyone that does not want to fast for 21 days is less than 1 day. Comments?

Going by popular opinion in the high level static performance circle, the generally accepted value is to fast for 6-8 hours before; the next level up in performance is seen after 18 hours. Beyond that things become very complicated. Furthermore, many divers still drink sports drinks (fast sugars) in the warm up even after fasting. This increases RQ and CO2 production but maintains efficiency and blood sugar. However contractions will come much earlier & harder if you go the sports drink route.

 

[osksa]

Ok thank you Eric! So summarizing we have:
0-6 hours: Bad performance
6-8 hours: Good performance according to Eric F
8-17 hours: No gains according to Eric F
18 hours: Better performance than 6-8
18-24 hours: Unknown, but we know from the study above that its bad after 24
24 hours to 3 days: Worse performance than not fasting according to study
21 days: Really good performance according to Eric F
Anything to add?

May I ask what you base the remark on a performance increase after 18 hours on?

Your last remark confuses me Eric, that drinking sports drinks gives more CO2 but maintains effeciency? According to my understanding, every molecule of CO2 produced is produced using an oxygen molecule, so increase of CO2 without using more oxygen seems strange?

 

[Nathan Vinski]

RQ means respiratory quotient. This is the ratio of co2 produced to oxygen consumed. After a long period of fasting or a diet heavy on fats (ketogenic diet for example) the body will burn fats as its primary source of energy instead of burning Carbohydrates (sugars). This is where RQ comes into play;

On a "Normal" diet where carbs are the primary source of energy we have an RQ >0.9 This means that for every Unit of O2 used in converting glucose to energy there are 0.9 or more units of CO2 produced.

On a Fat heavy diet or after a fasting period when the body is using fats as its primary energy source the RQ can drop as low at 0.7.. but lets say <0.9 So at this point for every unit of O2 consumed in converting Fats to energy there are less than 0.9 units of CO2 produced.

Efficiency is how much Energy (O2+ {Carbs and, or fats} = energy + CO2) is required to maintain function. After a fasting period we will have a lower metabolism requiring less energy but if we take a sports drink (carbs) our body will use the carbs as energy and produce 0.9+ CO2 to O2 instead of what ever lower RQ we were at before taking the sports drink.

 

[osksa]

Ok, I have info from two top ranking STA athletes. Accoring to what I heard, one fasts 8 hours and one 12. So my final conclusion after this thread so far is that something between 6-12 hours seems to be the range to try. This narrows down the number of trials to make to find what suits you a lot. Thanks to all participants. Do feel free to chime in with more info.