Emily White Most gym guys treat cardio like it is the enemy of everything they have worked for. The moment gains start showing up the treadmill becomes something to avoid completely. But an exercise scientist just broke down exactly what cardio actually does to muscle growth and the answer is not what most people expected.
The Fear Is Bigger Than the Reality
Mike Israetel, an exercise scientist at Renaissance Periodization, says the trade-offs between cardio and muscle boom are nowhere near as bad as the health club network makes them out to be. People are avoiding something that is certainly useful primarily because of an exaggerated fear.
There Is a Spectrum
The impact cardio has on your gains depends entirely on how much you are doing and how hard you are pushing it. A few moderate sessions a week sits in a completely different place on that spectrum than training for an Ironman triathlon.
Extreme Endurance Is the Problem
If you are training for extreme endurance events then yes, some muscle loss is going to happen. But that level of cardio volume is nowhere near what the average person lifting weights four times a week is doing or needs to do.
The Sweet Spot Is Real
Israetel says there is a middle ground where you genuinely get the benefits of both. Better heart health, better performance, longer life, and muscle growth that is still happening, just slightly slower than if you were doing zero cardio at all.
Five Percent Is Not a Death Sentence
Four thirty-minute HIIT sessions a week could cost around five percent of your maximum muscle growth rate according to Israetel. You are still growing. Just not at the absolute fastest rate possible. For most people that trade-off makes complete sense.
Israetel Practices What He Preaches
He trains jiu-jitsu three to five times a week himself and still maintains the kind of physique that comes from serious lifting. His own results back up exactly what he is saying about cardio not automatically cancelling out muscle gains.
Volume Management Is Everything
The key is making sure the cardio you are doing is not spilling over into your recovery from lifting. If your sessions are not leaving you too beaten up to train properly then the interference with gains is minimal.
Joint Health Matters Too
Israetel specifically mentions choosing cardio that does not irritate existing injuries or create new ones. The modality matters. Something that works with your body rather than against it changes the whole equation.
Overall Health Cannot Be Ignored
Health guidelines recommend at least 150 minutes of moderate cardio per week for good reason. Ignoring cardiovascular health entirely in pursuit of maximum muscle is a trade-off most people have not actually thought through properly.
Cardio Is Not the Enemy
The simple fact is that aerobic exercise completed sensibly complements schooling instead of competing with it. Managing the quantity, choosing the proper type, and no longer going to extremes is all it takes to maintain both jogging at the same time without one destroying the alternative.
