CommunityFood & Appetite

Post workout meal dilemma

13 replies12 peopleJun 6, 2026☆ Follow
Summary

Should I take a post-workout protein shake or meal on retatrutide while trying to stay fasted, or risk losing muscle?

Users on retatrutide who train in the evening debate whether to break their fast with protein or carbs after workouts. Several stress that hitting daily protein targets and consuming some post-training nutrition helps preserve muscle, especially in a deficit, while others note timing studies are mixed and GLP-1 drugs slow digestion so strict windows may matter less. A few suggest shifting workouts earlier or accepting a small meal to support recovery without derailing fat loss.

What this discussion establishesWhere people disagree

Whether nutrient timing remains important on retatrutide or is largely irrelevant due to slowed digestion and overall calorie deficit

Still open

How much muscle is actually lost without immediate post-workout nutrition versus staying fasted on this medication

Nothing here is advice.

13 replies · 12 people
PatientCinder17archiveopening postJun 6

Hi everyone. I'm in week three on reta at 1 mg once weekly and it's going well with steady weight loss. I train six days a week, eat breakfast around 7, brunch near 10, and lunch at 1:30 then stop eating to stay fasted. My gym sessions start after work around 5 and last one to two hours mixing cardio and weights. I'm concerned about losing muscle on reta so I'm wondering if a post-workout shake or a real meal once I get home would be better. I don't want to raise insulin or end the fasted state but I know protein is needed after training. Any experiences or thoughts would help.

SteadyCinder74archiveJun 6

For me the protein right after training is something I won't skip. I already struggle to hit enough protein daily and right now keeping muscle matters more than dropping more weight. As long as the scale keeps moving down a pound or two each week everything seems fine.

LevelMarble91archiveJun 6

Short version is yes. After strength work you really want carbs inside about thirty minutes to refill glycogen and protein inside two hours for repair. Recovery and growth happen overnight so the body needs fuel then. Moving the session to morning or adjusting when you eat might help.

SlowKettle51archiveJun 6

Plenty of studies exist on protein timing and results vary. Muscle protein synthesis rises after training and peaks around twenty-four hours later. I've started timing meals around that window. I do two long full-body resistance sessions a week now. I usually train in the afternoon so I add some carbs one to three hours beforehand. Right after I aim for at least thirty grams of protein within the first hour. For the full day after training I eat more freely and keep most of it healthy.

SharpWillow45archiveJun 6
↳ replying to @SlowKettle51

There is a difference depending on whether you're in a surplus or deficit. When overfed timing matters less. Weight training starts out catabolic so in a big deficit I think carbs before the session and protein afterward with a few carbs for uptake make sense. If I can't eat a meal inside an hour I grab a shake or at least a bar.

BlueTimber11archiveJun 6

I haven't seen any studies on pre and post workout protein or carbs for people using GLPs. With digestion slowed so much I have trouble believing the exact timing makes much difference.

SharpWillow45archiveJun 6
↳ replying to @BlueTimber11

From the examples I've reviewed the amount of muscle stayed the same even as total weight came down thanks to medications that target glp and gip receptors.

RustTimber71archiveJun 6
↳ replying to @LevelMarble91

Definitely move the workout to the morning.

BlueTimber11archiveJun 6
↳ replying to @SharpWillow45

Thanks for sharing. It's interesting to read but not enough for firm conclusions. Hopefully more studies will come out on this.

NorthMarble34archiveJun 6

I take a protein shake after the gym and double the scoops in water to get about sixty grams in one go. Sometimes near the end of my dose I add a hard boiled egg if I'm feeling hungry. Shakes let me hit my protein target without many extra calories. You still need some fuel even with reta in the picture.

PatientTimber45archiveJun 6

As long as you get at least one hundred grams of protein sometime during the day and keep training you shouldn't lose muscle. I went two weeks with almost no solid food and under fifty grams of protein because of bad GI issues on reta and dropped five percent strength but got it back within a week once I ate normally again. No need to train six days either, at least two rest days help recovery.

WryAlder31archiveJun 7

Protein shakes after training help hit daily targets if you're not already there at one gram per kg of goal weight. If you are hitting that then timing isn't critical but it can still support overnight synthesis. I once won a gym contest training fasted early in the morning and not eating until lunch yet still gained a kilo of muscle while dropping six kilos of fat. You can get good results without perfect timing. I'd rather burn body fat than worry about refilling glycogen when in a deficit anyway.

RustSignal22archiveJun 7

Protein timing after training shouldn't be underestimated. Skipping protein and carbs after a hard session raises the chance of staying more catabolic and hurts recovery. Fasting twelve hours after a one to two hour workout isn't ideal if the goal is keeping or building muscle. The advantages of staying fasted get overstated here. You won't necessarily burn more fat by skipping the post-workout meal. Resistance training raises muscle protein synthesis and mTOR. Without amino acids afterward that signal gets limited and AMPK pushes the body toward conservation instead of growth.

WryHarbour70archiveJun 8
↳ replying to @PatientCinder17 (opening post)

The point about conflicting data is fair. Everyone has their own approach. I think you need to find what keeps the diet and training sustainable for you. When I do a lot of cardio I get cranky without some carbs so I have about one hundred thirty calories of oats or oatmeal with blueberries. I still drink shakes during the day even in a big deficit or on keto. Good luck.

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