Cardio can cut muscle growth by 30% and strength by 18% if done wrong. Do it after weights or 6+ hours apart, stick to low-impact work like cycling, and keep it under 3 sessions a week or 20-30 minutes each if you're chasing size and strength.
Questions this video answers
Muscle growth impaired by roughly 30–31%; strength gains impaired by about 18% (2012 meta-analysis).
Separate sessions by at least ~6 hours when possible; one study showed markedly better biceps growth when cardio was done 24 hours after a workout vs. immediately after (2017).
When cardio sessions exceed about three or more times per week and session durations reach ~20–30 minutes, interference increases (concurrent-training meta-analysis of 21 studies).
When done properly, cardio can be an excellent way to improve your health, speed up fat loss, and can even help you build muscle and recover faster. But on the contrary, when done improperly, it does the opposite and negatively interferes with the gains you make in the gym. In fact, a 2012 meta analysis illustrates this point exactly and found that improperly combining cardio and lifting on average impairs muscle growth by roughly 30 31% and strength gains by 18%, which is obviously detrimental to your quest for gains. So the big question now is how exactly can you reap the various benefits of cardio without impairing your gains in the process? And in this video, that's exactly what I'll cover by going through four of the biggest gain killing mistakes that people make with their cardio routines One of the most common mistakes is doing cardio at the wrong time. Now, for most people, the most convenient time for them to do cardio is when they're already in the gym for a weights workout. However, when doing so, it's best that you perform your cardio workout after your weights workout rather than before. This is because when doing cardio before your weights, you'll be more fatigued during your lifting exercises and your strength will likely suffer as a result. In fact, a 2016 paper found that subjects that did a 20 minute cardio session prior to their weights workout performed perform significantly less reps on their lifting exercises as a result, which is in agreement with multiple other papers on the topic. Therefore, prioritizing your weights workout by moving your cardio to after your workout would be ideal for both strength and muscle gains. An even better option though, particularly if the cardio session you'll be doing is of moderate to high intensity and or longer than 30 minutes or so, is to perform your cardio and workout sessions completely separately. Supporting this Idea is a 2017 paper from the Journal of Sports Science Medicine which found that in untrained lifters, performing a 30 minute moderate intensity cycling session, 24 hours after a biceps workout as opposed to immediately after the workout, led to almost a two fold increase in biceps growth, which is theorized to be due to systemic factors actually interfering with muscle hypertrophy when cardio is performed after a muscle damaging workout. Now, although this study does have its limitations and likely would not apply for shorter and or less intense forms of steady state cardio, other research is in agreement that when possible, you should separate your lifting and cardio sessions by at least six hours apart in order to minimize any possible interference effects and build muscle faster. When most people Think of cardio they usually think of running, but this may in fact be the worst option if your main goal is to build muscle and strength. This is because running and other high impact modalities like jump rope, jumping jacks and high intensity interval training sprints all have a significant eccentric component to them and as a result causes a lot of lower body muscle damage that you'll then need to recover from, which can negatively affect your performance during your weights workouts, especially your leg workouts for example, whereas lower impact types of cardio don't require nearly as much recovery and therefore don't cause this issue. In fact, the meta analysis I mentioned earlier found that performance cycling concurrently with weights led to significantly less of a decrease in lower body growth when compared to running. Therefore, to minimize cardio's interference with your gains, you'll ideally want the majority of your cardio to be done with lower impact modalities that have a minimal eccentric component to them, such as cycling the elliptical and incline walking for example. And when you do choose to include more intense or high impact forms of cardio, then just be wary of the recovery that they'll require. You wouldn't want to do a sporadic 30 minute intense battle rope session the day before a shoulder workout for example, as that would likely negatively affect your strength within that shoulders workout. The last mistake people often make is just doing too much cardio. In general, this is detrimental mainly due to the principle of specificity, meaning that if your goal is to maximize muscle growth and strength, then your focus and your priority needs to be on your weight workouts rather than cardio. In fact, we can see from a concurrent training meta analysis of 21 studies that the more days per week you incorporate cardio, and the longer the duration of your cardio sessions, the more it interferes with your ability to build muscle and strength. The researchers found that once your Cardio sessions exceed three or more times per week and 2030 minutes in duration is when they really start to slow down your gains. Now, although I would not suggest necessarily using that as the upper limit of cardio you should be doing, it does nonetheless provide a general guideline to follow and more importantly illustrates that doing too much too frequently will negatively affect your gains as a result. One thing to realize though is that in almost all scenarios in the previous graphs, gains were still made, it's just that they were slowed down when additional cardio was added. Meaning that if your main goal is to drop fat while maintaining your muscle, then exceeding the prior recommendations is perfectly fine and is something I'll even do when I'm cutting. But on the other hand, if your main goal right now is to pack on muscle and build strength, then you can see how too much cardio quickly becomes counterproductive.
Now, I don't want you to be completely scared away from performing any cardio after seeing this video, but I do want you to realize that it does interfere with your gains when done improperly. But by performing it at the right time, sticking to mostly low impact cardio and not overdoing it with volume and intensity, then you shouldn't have to worry about it negatively affecting your gains. And for an all in one step by step program that shows you exactly how to properly optimize your cardio and your weights routine such that you can build muscle and lose fat as efficiently as possible, then simply head on over to built with science.com and take my Starting Point Analysis quiz in order to discover what program and what approach is best for you. Anyways, if you enjoyed this video then please don't forget to give it a like leave a comment down below as to what topic you like to see me covered. Next, subscribe to the channel and turn on notifications for the channel as well as this all truly does help me out. Thank you so much everyone. I hope you enjoyed this one and I'll see you next time.
