BodyBuilding Principles with Shelby Starnes Vol. 4 – Nitty-Gritty Cardio

Sure, you can always pick up unsolicited advice from your local locker room guru, but what are the chances of it actually being good advice? Unfortunately, the odds aren’t in your favor.

That’s why we gave renowned nutritionist and successful bodybuilder Shelby Starnes his own column to answer your training and dieting questions. You see, unlike the big guy at your gym, Shelby has worked with hundreds of athletes who are looking for the same thing as you: a ripped, muscular physique.

In this installment, Shelby tackles every cardio question you could possibly come up with to get leaner and increase your work capacity.

Read it, learn it, and apply it…and then print out a copy and give it to your locker room guru.

A Note from Shelby

Articles on cardio are never terribly glamorous. I’m sure we’d all rather talk about our new training routine, our crazy new preworkout supplement, or Jessica Albas amazing lips. However, glamorous or not, cardiovascular activity is a very potent tool for change in our physiques—not just cosmetically, but also in terms of health, recovery, and improved conditioning. 

In this article, I’ll address some of your most pertinent questions as to the nitty-gritty of cardiovascular activity – the what, how, when, and why. However, I have to warn you: cardio alone will not get you in shape if your diet sucks, unless you’re just one of those metabolic freaks who eats whatever you want and always has six-pack abdominal definition.

We normal folks have to pay diligent attention to all aspects of the bodybuilding lifestyle – diet, training, supplementation, and cardio – to achieve the results we desire. So with that warning out of the way, let’s get started.

Wait. You Mean I Can’t Have A Doughnut Beforehand?

Q: What’s the reasoning behind doing cardio on an empty stomach in the mornings?

Shelby: The argument for AM fasted cardio is that in the morning, after an overnight fast, your body is slightly glycogen-depleted and insulin levels are low, so fat will be the primary fuel source for cardio (at least for low to moderate intensity cardio).

The argument for “anytime” cardio is that the aforementioned variables don’t really matter; fat loss is simply a matter of calories in vs. calories out, and doing cardio later in the day will produce the same results given that the diet is the same.

In my experience though (and the experience of hundreds of my clients over the years), AM fasted cardio is superior, not only for the reasons mentioned above, but for the following as well:

  • Morning cardio is a great way to start your day because it releases endorphins that make you feel better both physically and mentally.
  • Getting it done first thing makes it less likely that you’ll skip it later. 
  • Morning cardio (especially high intensity activity) raises your metabolism for hours afterwards, so you’re not just burning calories while you’re on the machine but while you’re resting, too.

If you absolutely can’t get your cardio done in the morning, the next best time to do it would be post-workout (but prior to your post-workout meal), because this is another time when your body is glycogen-depleted. Make sure you bring your post-workout meal to the gym, however, so you can immediately replenish after the cardio is complete.

Some might worry about potential muscle loss when doing fasted cardio, but if your total diet is in line, then the chances of catabolism are very low. If the human body was so fragile that it lost muscle from doing some physical activity before eating, we never would have survived as a species.

Take Two and Call Me in the Morning

Q: Do you recommend taking any supplements prior to cardio sessions?

Shelby: Yes. To maximize the use of fatty acids for fuel during your cardio sessions, take a thermogenic fat-burner about 30 minutes beforehand. This will not only help liberate fatty acids to be used as fuel, it will also help to “wake you up” and get moving, and in addition, will help suppress appetite…not a bad combination while trying to lose fat! You can also take these before your weight-training workouts to accomplish the same things.

Do Very Low Carb Diets and High-Intensity Cardio Mix?

Q: I’m using a very low carb diet (trace carbs only) right now to shed some pounds I’ve picked up over the last few months. I love doing really high intensity cardio like Prowler sprints and other interval training, but I’ve heard this might not be a good idea while on a low carb diet. Why?

Shelby: Because glycogen levels are kept so low on a diet like that, cardio intensity should not be high. High intensity cardio uses glycogen as its main fuel source, and when glycogen levels are low, amino acids (i.e., your body’s muscle tissue) will be used to make glycogen via a process known as gluconeogenesis. Therefore, to keep catabolism at bay, always keep cardio at a low intensity (under 130 beats per minute). 

To make up for the lower intensity, you’ll typically need to increase the duration. Start off with 30 minutes per day, seven days per week, and gradually work up from there. When your weight loss plateaus, add another ten minutes daily.

The same applies to training. Because glycogen levels will not be very high (save for the day or two following your refeed), it would be wise to keep overall volume low. Forty-five minutes is a perfect workout length for a very low carb diet.

It would also be wise to keep the reps per set under ten on this diet, as lower rep training conserves strength and is also the least glycogen-demanding. 

There’s Always a Catch

Q: Would sled pulling combined with hill sprints be an efficient way to up my conditioning while burning fat?

Shelby: Definitely, but remember that diet will be the biggest factor in achieving your fat loss goals, not cardio.

Ever notice how all those people on the treadmills in your gym always look the same? They may be burning a couple hundred calories here and there, but I guarantee they are more than making up for it with less than stellar diets.  One bagel per day and their cardio efforts quickly go “down the tubes.”

Does Size Matter?

Q: Do your cardio recommendations vary much based on an individual’s size, or is that not really relevant?

Shelby: To a certain extent it does play a role. Larger individuals (in terms of body weight) will burn much more calories doing the same activity as compared to a smaller individual.  If a 250-pound man walks for 30 minutes at three miles per hour, he will burn a lot more calories than a 150-pound man walking the same 30 minutes at the same speed because his increased size and musculature requires more calories to do the same amount of work. Think of it like vehicle size: it takes more gas to power a bigger car over the same distance as compared to a smaller car.

On the other hand, larger individuals usually have more total fat to lose than smaller individuals, but because smaller folks usually get less “bang for their buck” from cardio, I usually prefer to push their calories lower (via diet) rather than have them do copious amounts of cardio.  It really varies from individual to individual though, as we all have very different metabolisms and hormonal profiles regardless of our scale weight.

Go Till You Drop?

Q: How much cardio is too much cardio?

Shelby: I’ve had clients do up to 20 hours of cardio per week, but most of them usually max out at around ten hours. Obviously, it’s very important to keep diet in check when performing this much cardio because you can risk losing muscle.  Other factors that play a role include an individual’s metabolism, how much fat they have to lose, and what sort of timeline they’re dealing with. 

Also, remember to keep cardio intensity in check. When I say I’ve had someone do up to 20 hours of cardio per week, that was all low to moderate intensity activity. If you’re using high intensity cardio, 20 hours would certainly be far too much. I’m sure I’m sounding like a broken record by now, but it’s true; every situation is different, so start off slow, monitor your results regularly, and adjust as needed to keep progressing towards your goals.

The Balance Game: Weights and Cardio

Q: How do you recommend balancing cardio and lifting when the goal is strength and muscle gain?

Shelby: Assuming that my clients are relatively lean, the max I’ll have my guys (and gals) do is 3-4 sessions per week, about 30 minutes each, mostly at moderate intensity, with maybe one high intensity interval training session per week. I prefer that they do their cardio on off days from training, or at least separated from training by 6-8 hours.

These few weekly sessions are usually enough to keep their conditioning in check and also provide benefit in the form of active recovery from their main training sessions. 

A sample weekly setup might look something like this:

Day Activity
Monday Squat training, no cardio
Tuesday Rest day, low to moderate intensity cardio (restoration, fat burning)
Wednesday Bench training, no cardio
Thursday Rest day, high intensity interval cardio (conditioning, fat burning)
Friday Deadlift training, no cardio
Saturday Rest day, low to moderate intensity cardio (restoration, fat burning)
Sunday Accessory work, low to moderate intensity cardio (restoration, fat burning)

If we find that this amount isn’t enough to keep their body fat in check, then I would likely tweak their diets before making any adjustments to their cardio.  I don’t like “wasting” a lot of energy in the offseason on cardio. In general, my advice is to spend your energy on your chosen endeavor (powerlifting, bodybuilding, etc.) and let your diet keep you lean.
If someone is doing very extensive training for their sport (in the form of multiple training sessions per day, for five or more days per week), I will likely lower the cardiovascular activity even further. As with anything though, it all depends on the specific client and the situation.

Written by Shelby Starnes

Discuss, comment or ask a question

If you have a comment, question or would like to discuss anything raised in this article, please do so in the following discussion thread on the Wannabebig Forums – BodyBuilding Principles with Shelby Starnes, Vol. 4 – Nitty-Gritty Cardio discussion thread.

About Shelby Starnes

Shelby is a successful National-level Bodybuilder & Powerlifter and has helped hundreds of athletes get into the greatest shape of their lifes.

  • 2010 NPC Jr Nationals – 5th place – Light Heavyweight
  • 2009 NPC Central States Championships – 1st place Middleweight and Overall
  • B.A. in Psychology with Departmental Honors – estimated completion May, 2008
  • 2nd place 198-lb class – 2004 APF Michigan State Powerlifting Championships
  • Overall Novice Champion – Motor City Bodybuilding Championships, 2005
  • 2nd place open middleweight- Motor City Bodybuilding Championships, 2005 (nationally qualified)
  • 5th place middleweight – NPC Junior Nationals, 2006

Whether you are a competitive bodybuilder looking for pre contest/off season assistance or simply just striving to achieve a specific physique, Shelby is available to set up custom diet and training programs to suit your goals.

For more information on his diet and training programs and prices, see here.