The bodybuilding “off-season” is upon (or nearly upon) many of you. You’ve been hungry and dieted down for a very long time. Some of you would rather gouge yourself in the eye with a sharp stick than even consider doing more cardio during the off-season. On the other hand, you want to be the best bodybuilder you can be, and you want to stay relatively lean. So, it makes sense, especially if you do cardio pre-contest, to think, “If cardio helped get me lean, it should help me stay lean, too, right?

In part one of this article series, we’ll examine the rationale put forth for doing cardio in the bodybuilding off-season. Part two will help you zero in on your own personal decision to do off-season cardio, and if so, what kind and how much.

The Question

I’ve been asked for my thoughts more than a few times about this topic: Should one include cardio during the off-season when constructing a “lean bulker?” Similarly, is doing cardio a good way to make “dirty bulker” a little less dirty? In other (perhaps more scientific) words, will doing cardio in the off-season improve the ratio of muscle to fat gained? For this article, we’ll exclude the possibility of a re-partitioning effect, i.e., concomitantly losing fat and gaining muscle mass, and assume that some fat is inevitable in the off-season.

The Rationale

The idea here seems to be that greater caloric expenditure (via cardio) necessitates greater caloric intake, and the more one eats, the greater the anabolic effect of nutrients and hormones like essential amino acids(1) and insulin(2). Beyond eating more, perhaps something about the cardio itself [e.g., increased insulin sensitivity(3)] might also help to minimize increases in relative body fatness(4).

The Evidence

Personal experience (yours, much more so than mine) will be invaluable for you to answer this question. However, there are number of factors, especially how one weight trains, that may help you figure out the when, how and why of adding cardio to an off-season regimen.  Here are some starting considerations for you.


Calories, Baby. Calories.

Cardio is not the only way to expend extra calories via exercise.  (Hear me out here. I’m not going to suggest some kind of 80’s aerobics routine.) Estimates of the caloric expenditure during heavy weight training range from about 400-600kcal/hour, and, of course, the more work done (thinking lifting really heavy loads doing large muscle group exercises), the greater the energy expenditure(5). If you are really going after it in the gym, this may be equivalent to upwards of about 60% of your maximal oxygen consumption(6). For a 20-something year old male, this would translate to a heart rate while walking on an inclined treadmill over 140 beats per minute(7). This is not bad, but it’s not the whole story.

Lifting weights—if you really, really go for it—provides a second metabolic punch in the form of excess post-exercise oxygen consumption, otherwise known as EPOC. EPOC refers to the oxygen consumption after exercise that is above and beyond that which would otherwise be required for activity and metabolism. Your factoid of the month: Depending on the fuel mix, this equates to about 4.7 to 5.0 kcals expended per liter of oxygen consumed(8).

Sure, you can and will burn extra calories in the form of EPOC after a cardio session, especially if it was intense(9), but we’re talking about only 20-30 kcal here(9-11). High-intensity interval training may double this value(9). Casual weight training, where sets are not taken to “momentary muscular failure,” isn’t much better than high intensity cardio as far as EPOC goes(10, 12). Train hard, however, and an EPOC equivalent to more than 100kcal can be produced(13).

Train really hard and it can get even better. One study found that a gut-wrenching, 30 minute workout of large muscle mass exercises (squat, bench and clean) taken to failure (12 sets total) raised resting metabolic rate by ~20%. We’re talking about a metabolic boost of over 700kcal over the next 1-2 days after training. Note again that this EPOC is above and beyond the energy cost of the workout itself(14). Do the math and a single weight workout lasting 30 minutes can result in a total ~1000kcal expenditure (most of which occurs outside the gym).

You’re Breaking Up…You’re Breaking Up…

A phenomenon I’ve witnessed (and experienced personally) is loss of and/or an inability to gain leg size and strength when trying to do cardio in the off-season. Clients who spend a lot of time on their feet (e.g., delivery jobs, construction, etc,) or who have a cardio-oriented hobby (hiking, etc.) may fall prey to this even without doing formal cardiovascular exercise.

Indeed, the science also bears this out. “Concurrent training” as it’s known—combining both endurance and strength training—may interfere with strength and muscle size gains(15, 16). Per the specificity of training principle(17), this may be because weight training and cardio stimulate distinctly different adaptive signaling processes(18-20) that can interfere with and counteract one another at the molecular level(16).

Photo courtesy of Jeffrey Sygo

However, many bodybuilders get away with doing cardio without suffering ill effects on (leg) muscle mass. Similarly, not all research studies find that endurance training interferes with strength training(15). Biological inter-individuality likely plays a role here, as we know that the extent of adaptation to both endurance and strength training varies substantially, so much so that some people essentially do not adapt at all to a structured training regime(21). So it follows that the degree of interference incurred during concurrent training would also depend on the person.

However, if, for instance, you’re a men’s physique competitor, simply don’t need or want more leg size (finding good fitting pants is a legitimate concern for large bodybuilders), or want whatever mobility may comes from doing your cardiovascular oriented activity of choice, the lack of leg size gains may not be an issue for you. Still, I generally believe that friends should not let friends skip leg day.

Cardio For Health Benefits

We all know that being physically active is good for you, and I often hear it said that folks are doing cardio for activity-related health reasons. The scientific evidence suggests that physical activity that gets you out of the couch potato category is especially beneficial(22), and that health benefits increase linearly the more active you are(23), even up to and beyond physical activity-related caloric expenditure of 2000kcal /week(24). Note here that 2000 kcal corresponds roughly to the sum of four “get after it” weight workouts, not including any extra EPOC-associated metabolic boost. Additionally, “dosing” with higher intensity exercise (like weight training) may be more beneficial than low intensity exercise for living a long, healthy life(25). It’s also been noted that becoming being, as well as being aerobically fit reduces one’s risk of dying, regardless of cause(26). Aerobic exercise definitely has health benefits, but so do most forms of activity.

Given the above, it’s not surprising that resistance training has been shown to improve risk profile for cardiovascular disease and diabetes, for instance, by improving blood lipid and glucose profile(5, 27). Thus, it seems that exercise in general, especially regular vigorous weight training (and not just cardio) is a viable way to create health benefits. For some of you who are especially health conscious, this may help answer the question: How much cardio “should” I personally do during the off-season?

In Part two of this article series, we’ll dig deeper into that question.

Photos courtesy of Jeffrey Sygo at 

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Disclosure: Elitefts does not profit from the sales of The Fortitude Training eBook or traffic to Scott Stevenson's website. We choose to share his work, products, and services simply because we believe he is among the best coaches in the industry.  - Dave Tate


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