HMB vs Leucine for Preventing Muscle Breakdown During a Cut

I am currently in a deep calorie deficit to get ready for a photoshoot and I am terrified of losing my muscle mass. I have been researching HMB and Leucine as anti catabolic supplements. I know that Leucine is the main driver of protein synthesis but HMB is supposed to be better at preventing breakdown.

Which one do you think is more effective when calories are low? I am training in New York and I am doing a lot of fasted cardio in the morning. I am wondering if taking HMB before my cardio sessions would be a good idea to protect my gains.

Has anyone used HMB during a contest prep or a harsh cut? I would love to know if it made a noticeable difference for you. I am trying to keep as much size as possible while getting my body fat down to single digits.

HMB is generally considered better for the anti-catabolic side of things while Leucine is the king of protein synthesis. If you are in a deep deficit HMB-FA might be worth the extra spend over the standard calcium salt.

I tried HMB a few years back and honestly the taste was like eating a bag of old gym socks. Does the free acid version actually taste better or is it still rank?

The taste is still a bit dodgy but most people use the clear gel caps for the Free Acid version now. From a coaching perspective, I suggest HMB for my athletes who are doing fasted cardio or very low-carb phases. It is much more effective at preventing muscle protein breakdown (MPB) than Leucine alone in those specific conditions.

I've just been sticking to 5g of Leucine with my pre-workout. Is it really worth the swap? Supplements are getting proper expensive in the UK lately.

Leucine is cheap and it works for signaling mTOR. But if you aren't eating enough calories the mTOR signal won't do much because there is no fuel to build anything. That's why HMB is the better choice for a cut - it's defensive.

Totally agree with AnimalLifter. I used HMB during my last shred for a Vancouver fitness show and managed to keep my strength levels way higher than the year before without it. It's not a miracle but it helps.

I read somewhere that you need about 60g of Leucine just to get 3g of HMB in your system. If that is true then just taking the HMB directly seems like a no-brainer if you can afford it.

Jimmy is right. The conversion rate is rubbish. I'm a fan of HMB for the recovery side too. Less DOMS when the calories are low.

Does anyone actually have blood work or scans to prove this stuff works or is it all just "bro-science" and marketing?

There are a few clinical trials showing HMB preserves lean mass in bedridden patients and older adults. Translating that to a 200lb lifter is the tricky part but the mechanism is sound.

I just stack them. Life is too short to choose. 3g HMB in the morning and Leucine-heavy BCAAs during my training. Overkill? Probably. But I feel better.

Is HMB better for fasted training? I'm doing 16:8 intermittent fitness fasting right now in Toronto and the morning workouts are killing me.

HMB is perfect for fasted training because it doesn't cause an insulin spike like Leucine or Whey might. Keeps you in that fasted state while protecting the muscle.

I'm 52 and I've found HMB is one of the few supplements where I actually feel the difference in my joints and recovery speed during a cut.

Wait, HMB helps with joints too? I thought it was just for muscle.

It's more about the connective tissue health during recovery. If your muscle isn't breaking down as much your tendons don't have to compensate for the fatigue as much.

I noticed a huge difference in my endurance when I added HMB. I was able to keep my reps high even when my calories were down to 1500.

Anyone have a brand recommendation for HMB in Canada? Half the stuff on Amazon looks like chalk dust.

Just look for the label with a USP stamp. Most of the reputable bulk sites are fine. Don't pay for fancy branding.