BCAAs and Intermittent Fasting

Hi! I'm Sara Solomon, a Team Bodybuilding.com & BSN athlete. Today I'm discussing BCAAs. I explain the what, why, when and how. Enjoy!

What are BCAAs? 

BCAAs stand for branched-chain amino acids.

BCAAs are a powder that you mix with water to create a delicious cocktail. Grape AMINOx is my favourite.

They are a recovery and endurance superfuel that:

  • Speed your post-workout recovery and reduce delayed onset muscle soreness
  • Provide you with electrolytes and 10 grams of amino acids per serving (they are sugar free and have negligible calories).



Why BCAAs?

I use them when I train fasted (I'm an intermittent faster) because I'm lean and my workouts are very demanding and I want to minimize muscle protein breakdown.

I want to make it clear that consuming BCAAs means I am not training completely fasted, which I want to avoid doing because training completely fasted would be detrimental (it's catabolic). I want to build muscle and get stronger ... but I want to achieve this without totally sabotaging my intermittent fasting regimen... hence BCAAs.

Pre-workout ingestion of BCAAs in the fasted state ensure that:

  • Muscle protein synthesis is stimulated and protein breakdown is inhibited.BCAAs contain leucine, which is a key player in protein synthesis.1
  • Maximal benefits for muscle protein synthesis are achieved with minimal caloric load.You would have to eat more than 500 calories to get an equivalent amount of BCAAs into your circulation.1

Many of you have been asking about my fasting regime, so for more information: Click here for my Fat Loss Fast System.

For fasted training, my pre- and post-workout BCAAs of choice are BSN's aminoX (no caffeine) and Cola flavoured aminoX (caffeine).

When to Take BCAAs: 


I drink 1 serving (10 grams) of aminoX 5 to 15 minutes before my fasted training session to sidestep the increased protein breakdown that happens when training completely fasted. The cola flavoured AminoX contains caffeine (100mg) so I like to use that one as both my pre-workout and my BCAAs in one product. I prefer not to take the caffeinated version after 3pm, to ensure I will have no issues falling asleep at night.


I typically break my fast about 1 to 2 hours post-workout, so I don't consume anything other than water post-workout.

What If? ...

If you train really early in the morning and break your fast later in the day, then have 10g of BCAAs 5 to 15 minutes prior to your fasted training session. Then about an hour after your workout, have another 10g of BCAAs, after which you will consume 10g of BCAAs every 2 hours until you break your fast. This will keep protein synthesis stimulated and it will minimize muscle protein breakdown.

Will BCAAs Break Your Fast?

Don't worry, you will still benefit from fasting even if you have the BCAAs (just don't have any carbs during your fast). Fasting increases your insulin sensitivity, so your insulin levels will quickly return to their fasted state levels despite having the insulinogenic BCAAs. So you won't ruin your fast by having the BCAAs, and the good news is that you will be able to get results from your fasted muscle-building/strength training sessions.

Prioritize What Makes You Consistent:

If having BCAAs allows you to be consistent with your fasting, then use them. Don't you think sipping on BCAAs during your fast is a better option than eating a granola bar during your fast? What you can consistently do, day after day, is the secret to success. Fixating on restrictive practices can make it really hard for you to remain consistent. Try to see the big picture. Why are you fasting? Do you need to be "perfect about it"? or can you take into consideration other perks, such as how fasting can improve your productivity (because you aren't eating all the time), it can work better with your schedule, and it can help you stop fixating on food 24/7. I have been drinking BCAAs during my fast since 2012 because it works for me!

I don't always train fasted (due to scheduling). If you train during your fed state, you don't have to use BCAAs, but I still like to use them.

Note: if you want to avoid BCAAs, you always have the option to train during your eating window.

p.s. I love to make my BCAAs into a slushy, especially in the hot weather. Just blend ice with water and a scoop of BCAAs. I like to use the grape and the pineapple flavours.

Which BCAAs? 

  • I'm a huge fan of BCAA products by BSN Supplements.
  • Flavour Recommendation:  Grape, fruit punch
  • aminoX does not contain any stimulants.
  • cola flavoured aminoX does contain stimulants (100mg caffeine). This makes it a great pre-workout (it gives you energy). It helps me get through my workouts (endurance aide).
  • aminoX has 10g BCAAs per serving.
  • They are sugar-free (sweetened with Splenda) and have negligible calories. Kindly note that you can purchase an unflavoured option of aminoX if you want to avoid artificial sweeteners.



**Contain affiliate links. I only recommend products that I use and love. But please do not feel obligated to purchase anything through my links. Click the Terms of Service to read my affiliate disclosure.


  1. http://www.leangains.com/2010/05/early-morning-fasted-training.html
  2. Karlsson, Hakan et al. Branched-chain amino acids increase p70S6k phosphorylation in human skeletal muscle after resistance exercise. American Journal of Physiology, Endocrinology and Metabolism. July 1, 2004 vol. 287 no. 1 E1-E7. http://ajpendo.physiology.org/content/287/1/E1.full
  3. Kendall, K. Why Women Should Take Creatine. January 24, 2017. http://bit.ly/2iKxJeE

Note: I am sponsored by BSN Supplements. I wanted to be sponsored by them because I really love their products!

Welcome! If you want to learn how to MOVE and EAT BETTER, you've come to the right place! I'm Dr. Sara Solomon. I'm a certified StrongFit coach and an intermittent fasting expert. I have degrees in dentistry (DMD) and physiotherapy (BSc PT), and I'm also a Pilates Mat Level 1 Instructor, CrossFit Level 1 Trainer (2016-2021), ACE personal trainer, NASM fitness nutrition specialist, a Mad Dogg Spinning Instructor, and a certified level 2 Buddy Lee Jump Rope Trainer and Ambassador. I'm a BSN Supplements and Til You Collapse sponsored athlete. My passion is helping people overcome restrictive diets and muscle imbalances so they can FEEL their very best!


  1. Are BCAA capsules sufficient?

    • You’d have to suck back a lot of them – which can become aggravating quickly. I find the powder/liquid approach forces me to drink lots of water, which keeps my belly full during my fast. Plus Gaspari Aminolast tastes yummy 🙂

  2. Hi Sara! To be absolutely clear… you take 3 scoops of BCAA’s per workout… going through a container of Aminolast every 10 workouts?? Yikes, that can get expensive. Thanks for all the information you post on your site! You are an inspiration! :o)

    • Yes, I do 2-3 scoops a day (pre workout, peri and post workout). It’s not wise to train completely fasted and the Aminolast is sugar-free, has minimal caloric load and minimizes muscle catabolism. At the end of the day, I still save money because I don’t spend as much money on food as I used to with my old grazing diet. Try to order from bodybuilding.com: they have the lowest prices! 🙂

    • Go to vitacost.com Dymatize Branch Chain Amino Acid powder is like $20 a bottle. 🙂 Lasts more than a month! 😀 Plus NO restrictions on quantity you can order. Bodybuilding.com limits order to a 30 day supply (Canada customs thing) which is like 2 bottles. 😛 Vitacost has their own customs broker so you don’t have to deal with the limit on bottles you can order to get into Canada! 😀

  3. Hi Sara

    If I am used to coffee in the mornings…and want to try your intermittent fasting plan…
    should I add Superdrive to the Aminoblast ? How much do you mix in the morning?

    Thanks Super Sara


    • coffee can be your preworkout Rob (caffeine). Drink it black. Just use the aminolast 1 scoop before working out, during & then after til you break your fast

  4. So much information on the web, but I keep coming back to your site for simplicity and clarity.

    One question I have is should you take BCAA’s on non-workout / rest days? If yes, what is your protocol?

    Also, do you consider a cardio only (no weight exercises) a day to take BCAA’s?


    • great question… I have been curious of this as well and can not find any info…. look forward to her response!

    • Paul – take the bcaa’s on cardio days.
      I am a pretty active person on a daily basis, so I do take the BCAAs every morning until I break my fast.
      If you do take a rest day (and you have a sedentary type job … ie not a construction worker), then don’t take the BCAAs. BCAAs are source of fuel for your body when intensely working out fasted to ensure no muscle loss happens.

      • Hi Sara,

        I really enjoy your website and videos …. funny, informative and effective. I came across your intermittent fasting protocol and realized I follow this on most days of the week. Not by choice but just the way my work schedule is laid out. I’ve always fasted pre-workout not intentionally but for convenience. I train early mornings and the thought of waking up 2 hours before to eat pre-workout! Forget it! I’d rather stay in bed longer 😉 I do consume a recovery BCAA drink and then a green smoothie. This usually holds over until 3-4pm then I eat a small meal. But by 6pm I need to eat a meal and then back to work for me.
        Can I consume my coffee 2-3 hours post workout?
        I am a Massage Therapist (work 5-6 hours/day) and train 5 days a week. Would I be considered an active person (not office job) and should I still take my BCAA’s on non train days?
        I follow a “Paleoish” diet (not too restrictive I do enjoy real cream in my coffee) will this work for me?

    • She answered this above. She said;

      ” Note: It’s only for fasted training. Don’t use it on rest days unless you have a very physical job (ie. construction worker).”

  5. Just to clarify… Drink 10 g 5-15 min before workout, another 10 g during the 25 min workout (but you don’t take a break in the workout, so just guzzle it quickly after 10 min of working out??) & the last 10 g IMMEDIATELY (?) after you finish your workout? Thanks, there’s been some confusion on the exact times to drink BCAA pre, during & post workout. Thanks so much!!


    • Katie!!!!! you are being over-technical again! 🙂 You don’t have to measure these out like antibiotics 🙂 I sip my BCAAs when I wake up. Then I refill my container for the workout. I sip it during my 10 seconds of rest between exercises (I just don’t do it on video, but now I will start!!!). I suck it all back during my workout because I work intensely! Then I refill it again and sip it (takes about an hour or 2 to sip through it). Then I have green tea or oolong tea or water until I break my fast.

  6. Thanks so much for all the information Sara I am finding it really useful, I just wondered should you use BCAA’s even when training without weights and just using bodyweight? I train in the morning fasted but at the moment am training at home and have limited equipment so most of my training is using body weight. Should I still expect to see results and will BCAA help with the results? Thanks

    • BCAAs will minimize muscle catabolism. BCAAs help fuel my workouts. I’d use them.

  7. Sara, do you ever fast for an entire day (and night) while doing the 20/4? Meaning, you would actually be fasting from 8pm until two days later at 4pm, a 44 hour fast. I used to randomly do 24 hour fasts but I’m wondering if I did that now that I’m on the 20/4, say on a rest day, I would just be negating my progress. Thanks.

    • I have been tinkering with 36 hour fasts on alternating days. I am very lean 😉

  8. Hello.
    My question is the Aminolast BCAA contains “Sucralose” . I beleave is the same in slenda. I understood that was sugar and not good for your body. Is that correct?

  9. I’m type-2 diabetic looking for an extra recovery boost from exercising…Can I take this???

  10. hi
    i want to know what should i eat after breaking my fast,and what other supplement do you use for example,l-carnitin,cla,green tea extract or caffeine and what about whey?

    • everything is explained on my website. Please read it.

      • hi
        i have been searched your website over and over again but i didn’t find somthing about other supplements expect BCAA and super drive 🙁
        i’m using cla and whey protein during 5 to 9 pm, l-carnitine before workout,BCAA before,during and after the work out and green tea extract during the day.i count my colories as you said and follow all the rules and i’m satisfied with the results.is it OK or not?

  11. Oh my goodness I barely read this and it’s sooo helpful I bought the aminos I love the flavor !! I was just drinking it during and was wondering about my post workout and now I know ! Thank you for being so awesome and helping all us fasters out ! I have noticed a change in only 2 weeks of fasting its wonderful !

  12. How do you know intetmittent fasting is the best option. Im.interested in the whole fat burning thing but i also wanna gain muscle mass and perform at my maximum. Doesnt that slow downmetabolism all those hrs without eatin

  13. Hi Sara, I really need help! I love your workouts and I am having amazing results with IF (I’ve lost 6 lbs in one month). I found BCAA’s I like, however, it is sweetened with sucralose. I didn’t think this would be an issue (I know I cannot drink anything with aspartame) but I am realizing that I am intolerant to sucralose as well (I have psoriasis and it flares up really badly when I eat or drink anything with artificial sweeteners). I know you said the powder is better because the capsules have to be taken in large quantities to get the right amount of BCAA’s so I am going to try some BCAA powder without artificial sweeteners (I have only found 2 and I think they are un-flavored). If for some reason I do not like them, can you suggest an alternative or am I just SOL???

  14. hello
    i just started IF and i have some questions
    i wake up at 6 AM and jump rope directly for about 30 Minutes and break my fast at 4 PM until 10PM.
    1- can i use fat burners like lipo6 black or oxyelite pro with BCAA ?

    2- can i skip the BCAA before workout and use it after work out and every 3 hours until i brake my fast?

    3- are my methods are good or bad?

    thanks and regards

  15. Hi Sara! I love the 20/4 IF protocol. It’s much easier to fast all day for me and then I get to go to bed full and happy! I have seen great things in only two weeks! I was lean to begin with, but now I can really see my ab muscles! its awesome! ;). And I just love your protein pumpkin recipes….I have made many of them and they are delicious! I have been fasting with amniolast b4, during, and post workout. I have also been adding SuperDrive and Gaspari 0 cal glutamine powder to my pre, glutamine with amniolast during and post workout! I really enjoy sipping them. Do you recommend the glutamine and SuperDrive if I have been making progress or should I cut them? Also….do you take your multi vitamins and CLA, etc..when you begin your feed period? What about a fat burner pre workout? Thanks

  16. I am interested in trying the IF but I work an alternate work schedule and I am not sure how I would do continued fasting. I work 11p to 7am and I sleep at 2 different times of the day, I go straight to bed when I get off work and I am up and have eaten breakfast and in the gym by 1 pm daily, and my second nap time is in the afternoon from 6pm to 930pm then I am up and getting ready for work again… I just purchased your quest dessert book and I am looking forward to trying then. … Thank you for any suggestions you may have

  17. Hello Sara,

    right now im doing the 5 meals a day(small) with cardio etc trying to loose weight for my wedding and i find this isnt working as it should of been, ive lost weight but the fasting you basically dont eat, is that how it works>??

  18. Hi

    I would prefer a non synthetic form as I don’t believe in consuming anything that has been artificially formulated. I am natural all the way. What’s the natural form of BCAA’s please? Also I don’t consume anything artificial. Doesn’t leave me with much choice lol!

  19. Hi,
    Can I use evogen “cellkem” its all I have right now but would like to try this fasting

  20. Do you think drinking something like these http://www.greenteahp.com would be ok while fasting?

  21. Hi Sara,

    Do you still use Gaspari Aminolast or do you prefer BSN’s AminoX as per this article? I tried to look at the dates of the articles, but as you update them I wasn’t sure which is most current.


  22. Hi Sara…I was wondering…I weight train in the morning and crossift in the evenings…will fasting help me out to loose some nagging fat. I eat generally well about 75 healthy but still have that pooch I cant get rid of. With as much as I work out I want to be sure my body has enough energy and to beast through my workouts. I look like your middle picture you posted today on facebook but with a bit more muscle in some areas. Help!

    • Support excited – Hoping to win!!!

  23. On the page prior to this link you are holding a picture of Aminolast not AminoX do you prefer one vs another?

  24. Hi Sara, I am fasting 20/4 for over 16 weeks, and I have GREAT progress. So I bought BSN AminiX, because was on sale. Can I mix Gaspari Superdrive and AminoX from BSN?

  25. Sara! ur fantastic, wish i found you sooner but Am excited to be a new fan 🙂

    do u take any type if fat burner or just sick to Ur cla,fish aminos etc?

    any brand you have as a favorite?

  26. Hi, I’m looking at ordering BCAAs and your book mentions Amniolast as your BCAA of choice although your newer website post has AminoX. Which of these is a better choice?

  27. I bought the lemon flavor aminolast. My question is how do you get it to mix? The powder does not seem to want to melt no matter how hard I shake it. Thanks for your help.

  28. Hi Sara,

    Just started IF and am already hooked! Seeing amazing results already and protocol B totally fits with my lifestyle and eating habits. The only thing is, I’m almost 100% vegan and the BCAA is obviously not vegan. I’ve been using them anyway, but I would love to find a vegan alternative. Do you have any suggestions? In the BCAA section at Popeye’s they had Vega Sport Recovery Accelerator… (http://vegasport.com/product/recovery-accelerator/) Would that do the trick??

  29. What’s the difference between AminoX and Aminolast? Are they the same?

  30. Sara, I started to do the fast but the BCAA that I have is aminolast I just bought this yesterday because I saw this in one of your video. I’m assuming it would work the same. Also I have rheumatoid arthritis what diet is good for me. Sometimes I can’t even workout like I use to my body retains a lot of water. Please help me I hate taking medicine I do the natural herbs like turmeric , ginger etc.

  31. Sara,
    You my dear have motivated me so much. I travel constantly and REALLY needed some new motivation!
    Keep it up!

  32. Can you recommend a BCAA w/o Splenda? I’m not a fan of artificial sweeteners.

  33. Sara, Question what time you start your fasting

  34. Hi Sara!

    I usually take Whey protein before and after my workouts. As I workout in the morning, during fasting, can I still take the protein shakes? Because both doses are about 200 calories…

    Thanks a lot!!!

    • Lolanda, get all the answers by signing up for the free tutorials at StartFastingToday.com 🙂

  35. Hi Sara, i try to always fast 12 hours everyday. Last time i did almost for 18 hours. It was great i eat normal food. veggies i didn´t binge. it was great but next day try to do it again but it was difficult not to feel super hungry!!! it´s normal’? how often do u fast? and how many hours??

    • hi Girls,does anyone know when you train fasted…Sara says 10 gr Bcaa pre 10 during & 10 post…. 10 gr? or one scoop which is 14.5 gr= 10 gr…i am confused 🙁

  36. hi Sara,so after i am done with the Wo,when can i eat ? lol

  37. Hi Sara, hope are well!
    First of all, fantastic website and awesome forum. THE most helpful site!!
    Just one quick question. I intermittent Fast 5 days a week to work in with my Crossfit training.
    My training takes place only in the evenings as I have to work around my job which also only gives me a small window to eat (Fasted state all day, train and the eat between 7-11pm)
    Other than black coffee and water which I take throughout my fast can I take BCAA’s through-out the day as well?! I don’t currently take any BCAASs just a post recovery shake and I don’t want to loose muscle (feel like I’m starting too)

  38. Hi Sara! I have been looking for a BCAA without sucralose because it causes problems for me. I found 2 sweetened with Stevia but I noticed one has 12 calories per scoop and the other one has 34 calories. Would that be considered breaking my fast?

  39. Hi Sara!

    I just signed up for your 6 day Kickstart. I’ve just started drinking BCAA’s in the past couple of months and I heard someone on Periscope yesterday say that BCAA’s can help stabilize hormones in females. Is this information correct?

    Thanks in advance for the info! =)

  40. Hi Sara
    Can u confirm is bsn amino x calorie free or 40 cals per serving as the container states ? Thanks

  41. Thank you for this… do you think it would be beneficial if I don’t train fasted?
    I work out in the evenings, until 6:45 or 7:45pm depending on the day so training fasted is not an option. Thank you.

  42. Hi Dr. Solomon,

    I saw your video, the same one you send out in the first email. over two months ago. I have been an IF for the past 4 + years and saw some great results. I also train early, 6:00am, M-F. But it wasn’t till I saw your video did I realize that I was lacking in my BCAA supplementation. After that video and adjusting my BCAA supplementation and rechecked my body composition yesterday and was astonished. I gained 3.3 pounds of muscle and lost 4.2 pounds of fat. And that was after left rotator cuff and bicep surgery in September 2016. Not much else has changed in my diet except for the added BCAA supplementation during the fasted state. I sincerely believe that you deserve the recognition for my success. Thank you.


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