Will Reta decrease running performance?

[u/Traditional-Yam6959]

Hi, I’m a 20F looking to lose about 5 kg using retatrutide. I’m a long-distance runner and have completed multiple marathons, so running is a big part of my life, but I’m aiming to lean out slightly.

I took my first injection about a week ago and have already noticed a drop in my running performance, especially a slower pace. From what I understand, this can happen due to factors like increased heart rate, reduced calorie intake, and lower glycogen stores.

My question is whether this is just temporary while I’m on the medication, or if it could have longer-term effects. Once I stop retatrutide after a few months, is it likely that my performance will return to baseline or even improve, or could this dip in performance carry over?

Would really appreciate hearing from anyone with experience or insight on this.

[u/Thee_PRIDE]

If you eat less and hydrate less, which people tend to do on any GLP-1, then your performance will naturally decrease. Reta in and of itself does not decrease performance but its intended effect typically results in drops in performance.

I didn't have much of a drop in my running performance (mind you I was only doing 2 mg a week) as I supplemented a stimulant and a nice karbolyn + electrolyte shake.

Edit: Speaking as a fellow runner, ex-track athlete.

[u/Traditional-Yam6959 → u/Thee_PRIDE]

Im also on 2mg a week and have been able to drinks as much as usual with extra electrolytes but less food ofc, but with extra protein and nutrients

[u/Ill-Nectarine-80 → u/Traditional-Yam6959]

Your athletic performance across all aerobic workloads will fall off a cliff when your glycogen reserves reach full depletion. This is why people optimising for success eat gels on the road in enormous amounts.

Any use of GLP-1s to drive a calorie deficit will diminish your overall glycogen reserves and indirectly impact your performance. First you will deplete all the rapid release glycogen in liver and as the depth of your deficit increases reserves will be drawn from your muscles and eventually you'll just run out. At this time, you can only burn fat which is much less efficient and creates a bottleneck that leads to the final cliff in performance. Reta especially does this because Glucagon receptors are always burning the liver glycogen.

[u/secret179 → u/Ill-Nectarine-80]

Then what will be soloution for slimming effect with no that?