Alternate Day Intermittent Fasting (ADF)

Alternate day fasting (ADF) is one of the best ways to begin intermitent fasting for fat loss and/or muscle definition. I wont go into all the details of an alternate day fasting program in this article but I'll instead explain some of the expected physical changes you may experience, why these occur and what to be aware of when monitoring your progress on an ADF program.

Many people who start ADF state that they rapidly take on a slightly leaner (or slimmer) appearance within the first fortnight. Regarding the appearance of looking slimmer within a short space of time, this will relate largely to an alteration in water balance due to the new eating pattern. Some changes will be as a result of fat loss as well. It happens with most rational diets and eating plans. 70% of our mass is just water and any small changes in that balance will make a noticeable visual difference. Also, glucose storage will alter due to the new eating pattern.

The levels of glucose stored in the muscles will probably fluctuate more on an ADF routine than on other eating plans, leading to variances due to fasting and non-fasting days. On non-fasting days glucose levels in the liver and muscles will rise, which will volumise the muscles with water as well (water is needed to hold all dissolved solutes in the body - which is why any increased solute storage in a muscle will volumise the muscle). On fasting days glucose will deplete first (before the ketogenic state sets in about 8-12 hours after the last meal in the period sometimes called "true fasting"). At that point the metabolism switches to almost total fat burning and insulin production virtually stops. It's notable that when the metabolic 'switch' takes place your blood sugar/glucose level will actually increase (not lower, as one would expect).

This is because when insulin is totally suppressed any resultant latent glucose leakage from the liver and muscles will not be significant enough to produce a new insulin response - due to high growth hormone levels developing in the 'true fasting' state. So glucose is no longer cleared from the blood at that stage. But after a short while some insulin production will re-commence (called "basal insulin sectretion"), which will clear out that extra glucose again (sending it back into the muscles and liver, where it will stay as a reserve for energy - or to balance low blood sugars, if you suddenly needed to exercise).

Be aware that hypoglyceamia is almost none-existant in non-diabetic people under ordinary circumstances, or in relation to fasting. I have not yet met a physician who has seen proof of hypoglycemia in a non-diabetic person. The feelings we sometimes get when we want to eat are mental cues, not physiological reactions. You almost cannot have a 'hypo' by fasting for a day (or even longer).

I am often asked if one should quit an ADF regime once target fat loss has been achieved. I have strong views on this, based on my own previous experiences and those of millions of other 'dieters' who have altered their weight by changing their eating habits. To answer this query: yes, you can stay on ADF indefinitely - but if you feel too much of a calorie deficit has formed increase calories during the eating days by having more meals (or larger meals). Try to keep the food consumption 'Low GI' - which refers to eating slow burn foods (as opposed to quick release sugars, etc). I used to stop IF completely whenever I got to minimum fat levels for the first few years after I took up the practice but I realised this was unnecessary and counter-productive (because it led to the common bodybuilder's 'bulking cycle' - which sees rebound weight gain over a short period of time). All diets should really be lifestyle changes and not short term measures - I am now convinced of this.

If you alternate days of cardio training and days of resistance training your fasting days are usually very good for medium intensity cardio (like jogging, etc). If you can do so, train near the end of the fasting period - so you can take in post-workout nutrition immediately after training (but this is not as important as some people think - I don't regularly do post-workout nutrition, personally, because I train in the mornings and only have my main meals in the evenings on fasting days).

Getting more pumped is a common experience for weight lifters who start ADF and it's almost definitely due to IF (people tend to intensify their workouts under an IF protocol due to genetic influences of IF on mindset and energy levels - much like taking caffeine affects energy levels and motivation).

Muscle preservation concerns are often raised by people who begin an ADF program and are serious gym users. A principle discovered by researchers into high intensity training (or HIT) is crucial to bear in mind in relation to muscle preservation. As long as you are able to maintain your workouts your muscle mass has not altered AT ALL. Never forget that. Working out is the sole determinant of a bodybuilder's muscle mass. I spent some time with Dorian Yates who kept emphasising this point to me in relation to dieting and 'protein sparing.' If your workout is the same this year as it was last year, your muscles will also be the same. If workouts intensify, mucles will get bigger. Use that principle to judge your 'real' muscle mass when on a calorie restricted diet. It's also notable that Dorian Yates didn't purposely bulk up off-season, he would prefer to go calorie neutral or into slight calorie surplus. He thinks there is little difference in muscle gain on a calorie neutral diet and on a bulking cycle (I think he has proved it with 6 straight Mr Olympia titles). So just adjust calories to control weight, don't actually abort the diet completely when you have reached your goals using ADF. That's what I've done for the last few years and it works much better (plus I remain lean almost all the time).

Regarding mental adaptation, you must work on your perceptions when you start ADF for the first time. You may have doubts and anxieties because the method is so new to you. Keep going for a while, it takes a long time to mentally change, sometimes. You will get used to new habits after about a month and you will find your mental state alters every few months. There will be times you'll love fasting and look forward to it and other times you will be much less keen. After a year it will normalise for the longterm, I think - and your attitude won't change much anymore - you'll always like fasting. But if not, try to alter the regime slightly - or use a different variation of IF instead. Some changes (like fasting every 2 days) can be added to an ADF routine as well, if they suit - but just for variety after a long spell on one routine. The outcome/results will be more or less identical if you use the method properly. The more you fast, the more you will need to eat on non-fasting days (to balance calories). The result will be unchanged.

From the mental perspective, be aware that motivation increases during fasting, largely for biological/evolutionary reasons. But calorie restriction (using any type of diet) can also increase aggression in some people - look out for that.

There is a genetic advantage to fasting over other calorie restriction programs because of the specific gene expression caused by fasting - regardless of whether or not there is weight loss or calorie restriction involved.

One more interesting fact in relation to bodybuilding and ADF - your body alters across the day (in appearance) - whether on IF or not. If you use IF, you will be leanest when you first get out of bed and for the first few hours of the day. By the end of the day you will show less definition due to less glucose in the muscles and high water consumption all through the day.

These are some of the common changes and things to look out for when you commence an ADF program. I hope this information is helpful to those who are contemplating starting an ADF protocol in the near future.