BCAA and Intermittent Fasting

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Branch Chain Amino Acids, otherwise known as BCAAs, are purported to have several major benefits for professional athletes and recreational fitness enthusiasts alike. BCAAs are made up of three essential amino acids – leucine, isoleucine and valine.


There is research to suggest that these amino acids, when consumed above a threshold amount, can increase protein synthesis, enhance endurance, prevent muscle ‘catabolism’/loss in muscle mass as experienced otherwise during intense training or periods of inactivity and increase strength.


Intermittent fasting on the other hand, although surrounded by some controversy (mainly about its safety), has touted benefits that included enhanced cognitive function, increased growth hormone levels, improved blood lipid profiles and improved insulin sensitivity. Studies have also suggested that intermittent fasting could even slow down the aging process.  I should add at this point that any fasting protocol adopted should be accompanied with medical supervision/recommendation and is not recommended for anyone with any type of illness or under the age of 21.


Scientists believe that the main mechanism behind the health benefits of intermittent fasting is related to a reduced secretion of the hormone which is called IGF-1, high levels of which are linked to aging and also several types of cancer. Increased growth hormone levels that are often experienced when exercising in a fasted state, are said to elicit greater benefits in relation to adaptation to training.


Intermittent fasting has several protocols or methods. You can fast on alternate days; consuming one fifth of normal energy needs one day, then the following day consuming a ‘normal’ diet.


The 5:2 fast is similar, but instead of fasting on alternate days, this protocol involves fasting for two non-consecutive days per week. There are several other protocols that can be followed – including the 16 hour fast were you consume all your calories for the day, within an 8 hour time frame.


BCAAs come in to play when training in a fasted state. Workouts in a fasted state should be 30 minutes or less and high intensity. This can enhance fat utilisation during exercise and increase growth hormone secretion; which in turn can lead to greater visceral fat loss, and protein synthesis. Consuming 10g of BCAAs around 30 minutes before training and 10g immediately after training in a fasted state is recommended by many fitness professionals in order to enhance the benefits of intermittent fasting.


In theory the increased levels of BCAAs in the body will take full advantage of the enhanced secretion of growth hormone and in turn enhance protein synthesis and muscle growth. Alongside BCAAs, if you adopt the alternate or 5:2 protocol, it would be worth considering supplementing with the likes of spirulina and/or wheatgrass powder to make the 500 or so calories consumed on fasting days, as ‘nutrient-dense’ as possible. Whey protein is also a possible supplement; with brands like Kinetica containing relatively high levels of BCAA. By the way, 10g of BCAAs contains about 40 calories, and there is debate as to whether these calories should be counted to the total calories during ‘fasting days’ on the alternate and 5:2 protocols.


Before considering intermittent fasting please read up as much as possible on the topic and consider potential side effects such as dizziness and light-headedness. Intermittent fasting is completely legitimate and backed by mounting amounts of research (it’s even on the BBC website) but can be dangerous for some individuals.


To round things up, here is an example workout routine and meal plan for the 5:2 or alternate day fasting protocol to give an idea of what they would typically consist of:

Intermittent Fasting Workout Example

Deadlifts – 3 sets of 4-6 repetitions
Push Press – 3 sets of 8-12 repetitions
Lat Pull down – 2 sets of 6-10 repetitions

Example Diet Plan for Alternate or 5:2 Intermittent Fasting

Spiriluna Drink
Nuts (Handful)


Salad – No Dressing
Wheatgrass Drink


Tofu Kebabs


About The Author

Following the birth of his son in 2009, Paul was unfit and sluggish. Since then he's been training using a range of exercise techniques and gained some valuable information over the years. Events he has completed to date are Total Warrior, Pier To Pier, Bamburgh 10k, Hamsterley 10k, Blaydon Races, Newcastle Stampede and over 50 parkruns. In 2012 he created his own challenge called the '12 Days of Christmas.' He raised over £1000 for Percy Hedley by running 60 miles to celebrate their 60 years. In 2013 he ran the '12 parkruns of Christmas' with friend Lee Nyland. The pair raised over £1400 for the Tiny Lives Fund.

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