Avoiding Cardio Could Be Holding You Back

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What you’re getting yourself into

~3100 words
8-12 minute read time

Key Points

  1. Lifting heavy things is more metabolically taxing than most people realize.
  2. Most people think of weight training as a purely anaerobic enterprise, but the majority of the energy you use to train is produced by your aerobic energy system.
  3. Cardiovascular training can improve your recovery between sets and workouts, and won’t interfere with strength or muscle gains if you do it correctly.
  4. Low intensity cardio should be prioritized over interval training for the most part.

Jacked sprint cyclists

Thusfar, most of the articles on this site that have discussed cardiovascular training have dealt primarily with why it’s not the devil – why it won’t make you weak.

This article deals with how it can be used to enhance your training and actually help you get stronger, faster.

You’ll notice that I won’t be citing as much research in this article as usual. That’s because the bulk of this information comes from four main sources:

  1. My Exercise Physiology textbook. A lot of the ground covered in this article simply relates to basic aerobic physiology.
  2. The work of Joel Jamieson. He’s got a LOT of great resources that address this stuff. I’d highly recommend his book “Ultimate MMA Conditioning,” and if you’d like a brief primer on his work, you should check out this lecture.
  3. These two fantastic review articles (One, Two).
  4. Discussions with my friend Alex Viada, who specializes in improving peoples’ endurance while also making them jacked.  If this subject interests you, I’d highly recommend his book The Hybrid Athlete.

First things first – a very brief overview of energy systems.

Your body’s No. 1 priority is staying alive. To do that, it has to produce energy at roughly the same rate you expend it. The metabolic currency of your body is ATP. There are two main ways your body regenerates ATP to produce energy: with oxygen (aerobic) or without oxygen (anaerobic).

Your body can produce energy much faster anaerobically. The fastest way is by using stored ATP, and replenishing ATP directly from phosphocreatine (PCr). However, this only lasts for 8-12 seconds. The next fastest way is by anaerobic glycolysis, which lasts for a few minutes, but which also causes acute muscular fatigue pretty quickly and doesn’t harvest very much ATP per molecule of glucose used.

Your body can produce energy aerobically for a very, very long time, getting every little bit of ATP out of each molecule of glucose or fat used. However, aerobic energy production is quite a bit slower than anaerobic energy production.

A one-rep max attempt relies almost exclusively on the anaerobic energy systems, particularly the anaerobic alactic (ATP/PCr) system. So, the thinking goes, since the aerobic energy system is almost entirely irrelevant when you’re on the platform, it must not matter very much for powerlifting.

This article explores why that’s shortsighted thinking. While your aerobic system isn’t doing much for you when you’re actually on the platform, it very strongly influences how hard you can train, which is ultimately what allows you to put up big numbers on the platform.


Lifting weight is metabolically taxing. Studies have found that doing 4 sets of 8 deadlifts with 175 kilograms burns about 100 calories. That’s roughly the amount of energy you’d burn running a mile if you weigh 130lbs, or running half a mile if you weigh 260lbs. Those numbers may not mean much to you right now, but I’ll show you why they’re important later.


An important thing to keep in mind is the “cost” of producing a given amount of energy aerobically versus anaerobically. We fatigue during exercise for a variety of reasons. I won’t even try to go through all of them here (and even if I did, all I could do is recount the best guesses we have right now. Because fatigue is so multifactorial and difficult to study, we really don’t know for sure what causes it, in all – or most – cases), but it’s pretty well-understood that burning through a ton of energy anaerobically in a short period of time is quite a bit more fatiguing than producing energy aerobically.

This is due to both local and central factors. Local factors have to do with substrate depletion (burning through PCr stores and, to a lesser degree, muscle glycogen), changes in ion concentrations that decrease the excitability of the muscle, and increases in metabolite concentrations and rather large decreases in muscle pH that can influence how hard the muscle can actually contract. Central factors mainly have to do with decreased oxygen availability, increases in certain inflammatory chemicals, a slight drop in blood pH, and other such factors that increase your brain’s perception of fatigue.

With aerobic energy production, you get a more modest drop in muscle pH and a much slower depletion of energy substrates. Central fatigue can certainly set in eventually, but it takes MUCH longer – usually accumulated fatigue after hours of continuous, strenuous activity or weeks of hard training.

Essentially, the more energy you can produce aerobically to meet a certain demand, the less you have to produce anaerobically, so the less fatiguing a given amount of training will be.

Reps and Fatigue Per Set

It’s important to keep in mind that even things we consider purely anaerobic still have an aerobic contribution, and it’s often larger than we think. For instance, this study showed that even for a 200m sprint (~20 seconds of all-out effort), about 30% of the energy produced was produced aerobically. For the 400m, 800m, and 1500m runs (considered heavily anaerobic events – especially the 400m and 800m), the aerobic energy system was already contributing more than half the energy produced by 15-30 seconds into the run. Even for relatively short efforts (like a heavy set of 5) the aerobic system is producing almost a third of the energy needed, and for higher rep sets, it’s producing more than half the energy.

The implication: The more powerful your aerobic energy system, the more reps you’ll be able to do with a given weight or percentage of your max, because every bit of energy you can produce aerobically is that much less that you have to produce anaerobically, which pushes off those factors that cause acute muscular fatigue. Also, if you do the same number of reps with a given amount of weight, less of the energetic contribution will come from your anaerobic energy systems, so the set will be less fatiguing. So you’re either looking at more work and the same fatigue, or the same amount of work with less fatigue; either way, you win.

This actually relates to a past article about sex differences: Women can generally do more reps with a given percentage of their 1rm because they generally have higher aerobic and lower anaerobic capacity per pound of lean body mass than men.

Recovery Between Sets

Although you’re obviously very reliant on your anaerobic system when you’re actually lifting the weights, what energy system do you think you use to recover between sets?

Your aerobic system is what produces the energy necessary to restore intracellular ATP and PCr levels, metabolize lactate, and generally get you headed back toward homeostasis so you can perform the next set. Better aerobic conditioning means you’ll recover faster between sets (and since you’ll be somewhat less reliant on your anaerobic system for each set, they’ll be less fatiguing in the first place) so you can handle higher total training volume.

Lifting heavy things is more metabolically taxing than most people realize Click To Tweet

If You Plan on Getting Stronger

Let’s revisit the studies showing that you burn about 100 calories deadlifting 175kg for 4 sets of 8. We’re going to use those numbers as a yardstick for a bit.

They found that energy expenditure was directly (and quite strongly) correlated to the amount of work being done. Work scales directly with the amount of weight on the bar. Lifting 100kg is twice as much work as lifting 50kg.

So, if you deadlift 175kg for a set of 8, you burn ~25 calories. If you deadlift 87.5 for a set of 8, you’d only burn about 12.5 calories. If you deadlift 350kg for a set of 8, you’d burn about 50 calories.

This is why a new lifter may be able to bang out sets of 10 squats while barely breaking a sweat, whereas a tough set of 10 may floor a stronger lifter. If you’re lifting twice as much weight, you’re burning through twice as much energy in the same amount of time, probably with a larger proportion coming from anaerobic sources.

So, if you plan on getting stronger – especially if you plan on getting really strong – it would probably behoove you to improve your aerobic conditioning. If it’s not a limiting factor now, it very well may become one as your lifts increase.

As The Workout Wears On

As you move through a workout, you become even more reliant on your aerobic energy system. One study illustrated this beautifully using 30-second rounds of all-out cycling, interspersed with 4 minutes of rest. Total work dropped from 18.7kJ in the first round to 13.8kJ by the third, illustrating the effect of fatigue.

More importantly, however, this study showed how the participants were producing energy for each round. These charts show the difference between their first and third sprints.

From Parolin, 1999
From Parolin, 1999


In the first, ATP/PCr and anaerobic glycolysis carry most of the load for the first six seconds, ATP/PCr drops off between 6-15 seconds while the aerobic system picks up more of the load, and by the last 15 seconds the aerobic system is doing about 50-60% of the work.

Contrast that with the third sprint where anaerobic glycolysis is nowhere to be found, and the aerobic system is doing the vast majority of the work from 6 seconds onward. Basically, after the first sprint, ATP/PCr gives you a 6 second burst, but after that, it’s all up to the aerobic system.

You may be thinking, “But Greg, I’m lifting weights, not cycling. And besides, aren’t those all-out bike sprints supposed to be the most brutal thing in the world?”

Not quite. They’re the most brutal test that’s used consistently in research, but only because there aren’t enough 700-pound squatters for the “set of 10 squats with 500lbs” protocol to be very popular.

The brutal cycling sprints are known as the Wingate Test, and going off normative data I found, they don’t hold a candle to our set of 8 deadlifts with 175kg. The mean for average power in the Wingate Test (for men) is 562.7 Watts, and the highest value in the dataset was 711.0 Watts. Watts are Joules per second, so you multiply those numbers by 30 to get Joules (16,881 average and 21,330 for the highest value), divide by 1000 to get kilojoules (16.9 and 21.3, respectively) then divide by 4.184 to get kcals (4.04kcals and 5.09kcals).  Since energetic efficiency for cycling is roughly 25% – meaning for every calorie burned, you only do about .25 calories worth of work on the bike – you end up looking at total caloric expenditure of 15-20kcals.

So a set of 8 deadlifts with 175kg burns roughly 25-60% more calories in roughly the same amount of time as the brutal Wingate Test. Similar values were obtained for the study referenced above – 18.7kJ on the first sprint is about 4.47kcals of work and 18kcals burned, and 13.8kJ on the third sprint is a scant 3.30kcals of work and 13kcals burned.

Most think weight training is anaerobic, but the majority of the energy used is actually aerobic Click To Tweet

All of which means, the huge shift away from anaerobic reliance and toward aerobic reliance from sprint 1 to sprint 3 not only applies to picking up heavy things, but probably understates the degree of the shift since the energy demands per set are considerably higher, especially if you’re quite strong. Unless you’re only doing heavy singles or doubles (to fit within that short window where you can rely strongly on ATP/PCr), your training probably relies at least as much (and probably more) on your aerobic energy system as your anaerobic energy system.

Injury Risk

Athletes become more susceptible to injury as they become fatigued. They lose a bit of coordination, and muscles themselves become less capable of absorbing force before a muscle strain occurs.

I’m not going to pretend like I have data to support this point, but I have seen my fair share of weight room injuries (and have had my own share of little muscle strains), and it’s pretty rare to see someone get injured on their first heavy set or two. It generally seems to happen later in the workout after fatigue has started to accumulate, which makes sense: more fatigue = more susceptible to injury. It doesn’t seem like too much of a stretch to assume that better aerobic fitness – meaning less fatigue per set and better recovery between sets – could reduce your injury risk in the gym.

Recovery Between Sessions

A central adaptation to aerobic exercise is increased parasympathetic nervous system (“rest and digest”) activity and decreased sympathetic nervous system (“fight or flight”) activity at rest. This means that between workouts, your body stays in a more robust recovery state.

Substrate Usage

Another adaptation to aerobic training is decreased carbohydrate usage and increased fat usage at any exercise intensity. This is probably more beneficial for a sport like CrossFit that has higher volume workouts, and whose competitions include multiple events per day over multiple days – sparing as much muscle glycogen as possible becomes a precious thing. But even in the case of powerlifting, a shift in substrate usage could make a small difference, especially in a calorie deficit if glycogen stores are already low since glycogen concentrations influence perceived exertion; low glycogen just makes everything feel harder, and improved aerobic capacity spares glycogen.

By Lance Cpl. Sarah Wolff [Public domain], via Wikimedia Commons
By Lance Cpl. Sarah Wolff [Public domain], via Wikimedia Commons


Now that I’ve made aerobic training sound like the best thing since sliced bread, it’s time to discuss the drawbacks. The most obvious is the “interference effect.”

A lot of the ways your body tries to adapt to aerobic training are in direct opposition to the ways your body tries to adapt to resistance training. Different metabolic pathways (AMPK vs. mTOR, though that’s not as problematic as most people think), using energy toward muscle protein synthesis vs. mitochondrial biogenesis, upregulation of aerobic vs. glycolytic enzymes, etc.

However, rumors of the interference effect, it seems, have been greatly exaggerated. At least, the meta-analysis on the subject found that it’s not aerobic exercise per se that causes the interference effect, but rather running in particular, probably related to the repeated eccentric stress of running. Cycling, on the other hand, did not hinder strength and muscle gains when combined with strength training.

Exactly zero track cyclists reading this article are at all surprised by that finding (refer to the picture at the top of the article).

The other drawback is simply the time commitment. Yes, it takes time. However, keep in mind that when talking about cardiovascular training for powerlifters, the goal isn’t to log 100 miles per week to qualify for the Boston marathon. It’s to attain a basic level of conditioning to fuel the energetic demands of training. For most people, you can accomplish that in 2 hours per week or less.

Can’t I Just Lift Weights?

Yes. Sort of. Actually, training to muscular failure has been shown to cause robust gains in aerobic capacity. However, most of the gains result from local tissue-level adaptations, not the global adaptations that come with dedicated cardiovascular training (increased cardiac stroke volume and increased oxygen carrying capacity being two biggies.  They may be increased somewhat with strength training, but not to the same degree). These tissue-level adaptations shouldn’t be discounted, but if all you do is lift weights to failure, you’re still missing out on some of the potential benefits.

What About Intervals?

The answer for this is essentially the same as the previous one: Yes, interval training can improve aerobic capacity by itself, and yes, it’s much more time-effective than low-intensity cardio. Intervals also improve anaerobic capacity to a much greater degree than aerobic training does. However, while you get some of the benefits you’d get from low intensity cardio, you don’t get all of them.

Low intensity cardio should be prioritized over interval training for the most part Click To Tweet

Furthermore, interval training is much more “costly” in terms of recovery, related to those central fatigue factors I briefly touched on earlier. Hopping on a stationary bike for 30 minutes with your HR at 130-135 won’t really affect your training very much tomorrow. Doing a few tough rounds of intervals (assuming you’re going hard enough to actually make them effective) can really put a dent in your ability to recover from your strength training, though. The idea of improving your conditioning in less time while doing fun movements sounds great on paper, but you pay for these advantages in how intervals can negatively impact the rest of your training.

Putting It All Together

The best conditioning plan for powerlifting will combine several different modalities (low intensity cardio, lifting to failure, and high intensity intervals) with an emphasis on minimizing the impact conditioning work will have on your heavy strength training.

Cardio can improve recovery and, if done correctly, won't interfere with strength or muscle gains Click To Tweet

My general recommendations:

  • Start slow. 2 sessions per week, both low intensity, and only 20-30 minutes per session with your HR around 130, or 60-70% of max heart rate. A bike is best, but incline treadmill walking is also a good alternative.
  • Only increase aerobic training load when you need to. Track your resting heart rate (measured first thing in the morning) and the work rate you have to maintain to hit a HR of 130. As long as your resting heart rate is trending down and/or you can pedal faster/against more resistance or walk faster/at a greater incline week to week, then don’t make increases.
  • Make increases slowly – 10 minutes more aerobic work per week. Evaluate your conditioning as you go. Your resting HR should end up somewhere in the 50s, and you shouldn’t have any issues recovering between sets. You should notice that the amount of training you can handle has increased quite noticeably as fatigue during training decreases, and recovery from training increases. Once you find your minimum effective dose for maintaining that level of conditioning, stay there – don’t do more for its own sake.
  • Once you reach three weekly sessions of 40 minutes apiece (again, only making increases as needed), evaluate your level of conditioning again if you’re still not sufficiently conditioned (see the previous point).
  • If your aerobic fitness plateaus at that level of low-intensity training, you may need to start including interval training. Start conservatively – 3-4 rounds of 1 minute intervals with 2-3 minutes of rest in between. Choose low-skill movements (NOT sprinting or weightlifting) like cycle sprints or kettlebell swings. Again, monitor improvements and only increase as necessary.
  • Do 2-3 sets to failure per muscle group, per week. Save this for your accessory work – going to true failure on squats or deadlifts regularly probably isn’t the smartest idea. You can get the same local aerobic adaptations with safer exercises. This is perfect for isolation work, actually. If someone tries to hate on you for being a bro and doing pec flyes or leg extensions, you can say you just care about maximizing mitochondrial biogenesis, thank you very much.
This graphic originally appeared in my new book, The Art Of Lifting. You can get your copy below.
This graphic originally appeared in my new book, The Art Of Lifting. You can get your copy below.

Wrapping it up

Whether we’re talking about the Chinese weightlifting team’s morning jogs, Andre Malanichev’s 10km runs, or Chad Wesley Smith who does enough cardio that he’s only a couple seconds off the world record 500m row, a lot of the best lifters in the world already know how dedicated aerobic work can benefit their training.  Especially if you’re finding yourself huffing and puffing between sets or having issues recovering between workouts, improving your cardiovascular conditioning may be exactly what you need to keep moving forward and getting stronger.

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117 thoughts on “Avoiding Cardio Could Be Holding You Back”

  1. If cardio equipment isn’t an option, is brisk walking a viable substitute or should I just focus on the accessory lifting approach mentioned at the end of the article?

  2. Just to confirm, you’re saying that if your resting heart rate is in the 50’s (mine is around 50-53) that your base level of aerobic fitness is fairly good? To decrease the rest time between sets further, would you then think that increasing my cardio further would be beneficial? or just maintain what I’m doing? I’m not a lifter specifically but am trying to use it as supplementary cross-training for rock climbing. So, for me a ‘set’ would be a specific climb (5-12 moves each)

    Great info!

    1. Honestly, I’m not 100% sure what the aerobic demands of rock climbing are. I’m assume they’re higher than the aerobic demands of lifting, so if you can climb well, you’re likely EASILY in good enough shape for lifting.

  3. Not sure if you’re going to get this but you’re article comes at an interesting time for me. Coincidentally have been working on increasing the amount of volume I do in the gym, doing sets of 8-10 on compound lifts and kettlebell swings for sets of 20, basically trying to increase my work capacity. Also I throw in weekly 1-3 mile walks when I can.

    I don’t do 8-10s exclusively I’ll work up to heavy sets of 3-5 also. I cycle in volume days and heavy days or even a warm ups of 8-10 reps to what is a heavy top set of 3-5.

    To be completely honest I just wanted to be able to recover faster and put on a little muscle. I’ve been eating lots of clean food and my body weight has shot up 10 lbs at about the same bodyfat if not a little leaner than before.

    Point is I increasing my work capacity aka aerobic capacity has paid dividends, I feel stronger and healthier than I did before and at about 10 lbs heavier bodyweight (from 220-230). I also recently did a push/push smoking weights I had previously thought were true 1rm maxes.

  4. Andrew Pizzi Wilson

    Hi, Greg.
    I just wanted to know what’s your take as regards when to do the cardio session for the aforementioned purposes. Right after resistance training?
    Thanks for the article.

    1. Ideally away from training, later in the day if possible, so you’re not fatigued from your cardio, which would impact your lifting. The second best option is after training, so you can lift when you’re fresh.

      That being said, there are some molecular arguments that say everything I just said is wrong, and that you should do cardio earlier in the day, or right before your training session. I can tell you, though, if you’re in horrible shape so that cardio wears you out, or you’re reasonably strong, and experienced enough that you can notice moderate fluctuations in your fatigue level, this is probably not the way you want to go. It may improve aerobic adaptations, but your strength/size progress will probably suffer. But, in the interest of presenting the counterargument to my position, here it is: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4213370/

    1. Cardio is derived from the ancient Greek word καρδία (transliterated kardía). Spanish grew out of Latin. The Latin word for heart was cor. So, no. There are no obvious etymological links that would make one believe cardio was a Spanish word.

  5. I didn’t understand the bit “The mean for average power in the Wingate Test (for men) is 562.7 Watts, and the highest value in the dataset was 711.0 Watts”. Would it not be total power rather than average that you would need to compare to the 8 deadlifts? Thanks

      1. The simplest explanation for that is that training at 70% of single leg VO2max was probably way too low of an intensity to cause any central adaptations. If I’m remembering what I learned in ex phys correctly, single leg VO2 is about 70% of two-leg VO2, so working at 70% of single leg VO2 would have them working at under 50% of their actual VO2 max.

  6. Great article. Made me rethink what I’m doing. For the last few years all I’ve done is lift weights really. Started noticing I get out of breath so easily even demonstrating exercises lol. I just calculated my stats though and my resting heart rate is 63. I thought it’d be higher as my cardio is terrible. 18 speed and around 7/20 or 25 on the bike had me at 150-160 HR and cross trainer within 1 min I was 160 and 5 mins at 170+! this is extremely light cardio too. So with 60-70% being the goal, I cannot even get mine down to that without barely moving the machine. So is it possible that because I train, my max heart rate is actually higher than it is for others or is it just a case of huge lack in fitness and need to work to get HR lower for the same workload?

    1. It’s probably just a lack of fitness at the moment. Max heart rate is largely unaffected by training status; it varies person to person, and it declines with age, but training don’t impact it.

  7. HI! Very interesting article. What do you think of skipping rope? Should i do it merely as warming up before lifting, like 10-15 minutes, or on rest days? How about 10-15 minutes every day, wheter it is a rest day or a gym day?
    Thank you very much for the info!

  8. Hi Greg. Great article. I could definitely stand to do more cardio.

    I’m just wondering about the reason to do LISS over HIIT. You say,

    “However, while you get some of the benefits you’d get from low intensity cardio, you don’t get all of them.”

    What is it that LISS offers that HIIT doesn’t (other than being easier to recover)? I don’t really follow the logic of prioritizsing LISS over HIIT, as I’m under the impression HIIT is effective at training both the aerobic and anaerobic and is less (? I guess depends on modality) likely to cause muscle catabolism when compared to LISS.

    1. Anaerobic work (including lifting) primarily causes concentric cardiac hypertrophy, whereas LISS primarily causes eccentric hypertrophy (https://www.researchgate.net/profile/Ola_Gjesdal/publication/51745685/figure/fig2/AS:267794482724922@1440858588961/Figure-4-Concentric-and-eccentric-hypertrophy-can-be-distinguished-by-the-orientation-in.png). Concentric hypertrophy isn’t “bad,” but eccentric hypertrophy is the main functional adaptation that increases the efficiency of the heart and the amount of blood it can pump per beat.

      The autonomic nervous system adapatations (shift toward parasympathetic and away from sympathetic) are unique to LISS as well.

      There’s also the issue of how much you can improve with one modality vs. the other. HIIT pretty much only causes aerobic adaptations in people who are entirely or almost entirely untrained, or when added to a program focused around LISS in people who are already trained. HIIT on its own generally has pretty minimal effects on aerobic development on people who are reasonably well-trained.

      I’m not overly concerned with anaerobic development for most lifters who are already training pretty hard. Most lifters have reasonably good local and global anaerobic development already just from lifting, assuming they aren’t doing exclusively low reps with super long rest periods. Not world-class, of course, but in terms of prioritizing aerobic or anaerobic development, there’s generally much more room to improve aerobically (which helps decrease anaerobic fatigue).

  9. Hi Greg,

    As someone who is pretty poorly conditioned, I actually managed to go through 30 minutes of cardio at 130bpm. I found it very easy, and could easily hold a full conversation throughout. Is this the correct level of intensity for what you recommend? Or is my heart rate monitor wrong?

    Thank you.

    1. I think a lot of people are surprised at how low of intensity it actually is. Stick with it for a bit. If your conditioning is improving, there’s no need to do more than that. If not, increase the duration and/or frequency.

    2. A couple questions:

      1. My morning resting heart rate is generally not my lowest heart rate throughout the day. Not sure why (cortisol?) but often if I randomly measure my resting heart rate in the afternoon it is significantly lower. Should I still use the morning resting heart rate as the basis for judgement?

      2. I’ve been following these recommendations for about 6 months and I still can’t get into the 50s. Usually I’m in the mid to high 60s. Should I go higher than 130 bpm? Maybe 135 or 140? I am kind of hesitant to add HIIT since I am already very sympathetically dominant.

      3. Why is the bike recommended as the preferred cardio method? I would think this would be inferior because it concentrates the work to less muscle mass than say incline treadmill walking. I find I get a burn in my quads (a sign of being anaerobic?) at a lower heart rate than incline treadmill walking. Also Joel Jamieson recommends using multiple exercises in single cardio session, say 10 minutes on the bike, 10 minutes on the treadmill, 10 minutes rowing, and 10 minutes on the stair climber for a 40 minute session. Thoughts?

      1. Does your AM heart rate still track pretty consistently, though? As long as it doesn’t fluctuate too much under normal circumstances, it’s probably fine to use.

        Mid to high 60s isn’t bad. If you’re sympathetic dominant like you said, that may actually be pretty low for you. How’s your conditioning changed in that time period? Can you do faster speeds/higher inclines/high resistance/etc. at the same HR as before?

        The biggest reason I recommend cycling is that it’s the modality with the most evidence showing it doesn’t cause a meaningful interference effect for strength and hypertrophy (https://www.ncbi.nlm.nih.gov/pubmed/22002517). However, I’d assume that most low-to-no impact forms of cardio would work similarly well (pretty much anything except jogging).

        1. Thanks for the response.

          I have notice my conditioning has improved, I just can’t seem to figure out if it is adequate because I can’t get my heart rate to the point you suggest (in the 50s). I think I recover well in between sets. I have not noticed a difference in recovery between training sessions.

          The incline/resistance/speed seem to fluctuate, but I seem to be about the same to keep my heart rate at 130 bpm. That’s why I am wondering if increasing the intensity to 135 or 140 would be beneficial.

  10. Hey Greg, a few quick questions:

    – When you say add 10 mins more work per week, do you mean 10 mins total, or 10 per session?

    – When do I stop adding 10 mins?

    – When do I add a third session?

    – Would adding more than 3 sessions yield benefits faster?

    – Can I do sessions two days in a row? After lifting?


    1. 1) 10min to one workout

      2) ~60min per session

      3) when you’re already doing 60min (or at much as your schedule allows for, if it doesn’t allow 60min) in the first two sessions

      4) potentially, but it would interfere with lifting more.

      5) yep!

  11. I really like this article, and have read it several times to let things sink in. I am new to lifting and am also pretty out of shape, and I wanted to add a couple of cardio workouts a week as you advise.

    However, I had a problem following your guidelines. Right now I do 25-30 mins of steady state cardio on the elliptical at an intensity that, while tiring, is still not so bad that I totally collapse afterwards. I can follow the podcast I listen to and could probably speak in breathless short sentences. However my heart rate is around 160-165 while doing this, not your target of 130. Is this a problem? Should I lower the intensity of my exercise so that it’s no more than 130 on average, even if this doesn’t really feel like exercise to me? Or should I go by my subjective perceptions of intensity. I’m 26 and male if that makes a difference.

  12. I really enjoyed this article. The arguments you laid out for including traditional cardio in a strength program make a lot of sense. I am interested in looking further into the aerobic contributions to various RMs. From the article:

    “Even for relatively short efforts (like a heavy set of 5) the aerobic system is producing almost a third of the energy needed, and for higher rep sets, it’s producing more than half the energy.”

    Is this based on the estimated time it takes to complete the set, or is there research that bears this out? For something like squats, the number of breaths between reps can largely impact the time it takes to complete a set. I would imagine that the metabolic profile would look different for a heavy set of 10 done with 2-3 breaths between reps versus only 1 breath per rep.

    1. >Is this based on the estimated time it takes to complete the set, or is there research that bears this out?


      >I would imagine that the metabolic profile would look different for a heavy set of 10 done with 2-3 breaths between reps versus only 1 breath per rep.

      I don’t disagree with that at all. I was just giving some rough estimates. It’ll obviously vary person-to-person, and differ based on the way those squats are executed

      1. I do basic starting strength squat/deadlift/bench 2x per week, I really like HIIT (those Darebee-type workouts) but are you suggesting I run/bike instead? Would HIIT once/week and low-intensity once/week be an acceptable routine? Thanks sir

        1. Honestly, if you’re just starting out, it probably doesn’t matter TOO much what sort of conditioning you’re doing. The potential for the interference effect to make much of a difference starts increasing with increased training status.

    1. “And endurance exercise is directly antagonistic to strength, because an endurance adaptation occurs at the expense of strength.”

      That’s not always true (http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0149082; https://pdfs.semanticscholar.org/d984/41780be26c86caa394d8a8550c3270e6a039.pdf) and, when it is true, the degree to which it compromises strength gains is often overstated, unless your aerobic training volume is super high (https://www.ncbi.nlm.nih.gov/pubmed/22002517).

      That’s really central thesis, and it’s shaky at best. The rest is basically just “you shouldn’t rely solely on running, and should also do some strength training.” And like, yeah. That’s not going to get any pushback at all.

      My biggest issue is that it presents the options as binary (lifting OR cardio). Why not both?

  13. Hi Greg,

    what do you think about bodyweight circuits, either for low and high intensity cardio? Are they a viable option, or the risk of interference is too high?
    I am thinking mainly of low skill/impact activities of course, like bodyweight squats or locomotion drills (https://gmb.io/locomotion/).

    In this regard, are you familiar with HICT, High Intensity Continuous Training (http://robertsontrainingsystems.com/blog/rts-coaching-high-intensity-continuous-training-hict/)?


    1. I think they’re a viable option. Probably not as efficient as plain old cardio modalities, but they’d get the job done for most lifters.

      I’m familiar with HICT. It’s an oxymoron. If you’re staying below your anaerobic threshold, it’s low intensity training.

      1. Thanks Greg.

        To be honest, I’m not a huge fan of bodyweight circuits if they implement things like push-ups or rings rows, because they basically turn up to a very high rep set (with quite a lot of eccentric stress to boot), and I don’t really know how this could be useful.

        But after reading your excellent series about concurrent training, I was looking for an upper body based cardio modality, as I don’t have access to a rowing machine nor an elliptical trainer.

        So, about HICT, is your opinion negative overall?

        1. You could swim, with minimal contribution from kicking your legs. Rowing has a pretty large upper body component as well.

          I honestly don’t have much of an opinion about HICT at all.

  14. Hi Greg,

    With regards to the interference effect of running due to the eccentric stress of the activity, doe this hinder strength and muscle gains of the upper body as well? Or is it only limited to lower body strength and muscle gains?

    Thank you!

  15. Walking is part of my commute. I walk every working day (5days/week). Last time I measured BPS during walking and average was ~126BPS, so it’s within 60%-70% of MHR.
    My walking looks like:
    – 10mins of walk
    – 5mins rest
    – 10mins of walk
    – 30mins of rest
    – 15min of walk
    – 8h of rest
    – 15min of walk
    – 30mins of rest
    – 5 mins of walk
    To sum up it’s almost an hour of brisk walking a day.

    My questions:
    1) How different is one hour of walking at once and in dispersed way as I presented? Do i benefit as if I would walk one hour continuously? Can I replace cardio program you proposed with just walking this way?
    2) Can such amount of walking decrease my lifting gains?

    1. I think most of the research indicates that each session of “cardio” needs to be at least 15-20 minutes long for longitudinal gains in aerobic fitness. And nah, I highly doubt that that amount of walking will have any meaningful effect on your gains.

  16. Hey Greg,

    I really enjoyed this article, good work my man. I’m curious as to how you think sauna use could impact this. Sauna has been shown (and personally I’ve experienced) to increase HR into and above the range described in this article. Do you think that many of the benefits of low level aerobic conditioning are because of elevations in HR, or is that simply a side effect of the beneficial aerobic work?


    1. Sauna can be beneficial, but for entirely different reasons (and it doesn’t replace cardio). The increase in HR matters less than what’s causing the increase in HR. If an increase in HR was all that mattered, you could get in shape from slamming red bulls and snorting coke around the clock.

  17. Hey Greg,
    The only equipment i have is the road. What conditioning exercise do you recommend for me? My breath is through the roof between sets and i think i really need to focus on conditioning.

  18. So, on the flip side would you say that lifting weights improves a lot of the qualities that cardio does since it taxes your aerobic energy system quite a bit? So for the average Joe that just wants to get in shape and get healthier but doesnt have much time to train cardio would be a waste of time and dedicating all the time he has(2-4h/week) to lifting would be a way better choice?


    1. It depends how good of aerobic shape one wants to get in. I mean, cardio will build some muscle in completely untrained people, and lifting will improve aerobic conditioning in completely untrained people, but it’s not going to get you very far.

      1. Greg,

        This is such a good article. It’s refereshing to see someone dispelling myths and putting out good quality information that backed-by-science.

        Awesome work bro.

  19. I have noticed as I have gotten stronger that my heart rate and breathing are way up between work sets. I see why now. I guess it is time for the old stationary bike! Thanks.

  20. Some of your links are not working anymore, specially the ones where you detail out where you were pulling your information from for this article at the beginning.

    Thank you.

  21. I’m a boulderer who used to do strength training. I’ve lost some muscle dieting down to be lighter for climbing. I was planning to run a strength block in a small surplus to build (back) a little upper body muscle (mainly bench/arm work with a bit of pulling to supplement the back work from climbing), without looking to add mass to my legs, which is generally deleterious for my sport.

    The main cardio I have available to me is jogging. Would the interference effect be specific to my lower body since they are the muscles involved with running? Or is it a systemic effect?

      1. Good article. I think I’d rather do HIIT for cardio because I’d be more likely to comply long term rather than having to get on a bike and pedaling for 30 minutes each time at low intensity for example. Isn’t the effect cumulative anyways? For instance, you wouldn’t see the effect of HIIT on strength levels in the following workout but it would gradually creep up and you would hit a wall sooner than if you didn’t push HIIT hard during that training cycle

        Also an exercise physiologist, Bart Kay, has said that we do not want to be doing low intensity cardio. At least one of his main points is that it shrinks or changes muscle fiber composition

        1. If you think you’d be more likely to stick with HIIT, do HIIT.

          He’s probably referring to low-intensity cardio in isolation. I haven’t seen any evidence that its effects on fiber-level adaptations (regarding size and fiber type conversions) during concurrent training are meaningfully different than HIIT

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