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Which is More Important: Cardio or Weights?

By Alexander VanHouten, Master Trainer & Life Time Education Specialist

A client asked me recently if they had to pick only one form of exercise, what should they do?

I love and hate questions like that.

I hate those questions because everyone knows that both do very important and good things for you. So you should do both.

In reality though, I love that question because it really causes to you to draw a line in the sand.

What does lifting weights actually do for you?

What does cardiovascular exercise really do for you?

Let’s explore the true nature of each type of exercise and define what each actually does for your body and health. Like online shopping, by the end of this, you’ll be empowered to pick and choose what you do at the gym today to get what you really wanted out of your workout in the first place.

So…what’s the difference between cardio and weights?

A “bro” walks into the gym complete with flowing cut-off graphic tee, a shaker bottle full of a pre-workout concoction and shiny blue BeatsTM headphones blasting today’s workout mix. Since everyone who is taking time to make better themselves at the gym is worth high-fiving, I flag him down.

“Hey man, what are you working out today?” I say initiating a fist-bump with a smile.

He smiles back, displaces his left headphone, and pounds it. “Weights are on the menu. Back day.”

“Awesome! What are you doing for cardio?” I’m genuinely curious.

He grins. “Lift weights faster!” Funny guy.

In true “bro-fashion”, he has made a slightly scientific point while dodging the black and white truth.

On one hand, he’s right.

You should exercise because it’s good for you regardless of how you’re doing it. Even the guy in the squat rack doing bicep curls is doing more for himself than the guy mindlessly watching NCIS reruns on Netflix (though some may argue the former is far more frustrating to society than the latter).

AND you should do what you love because you’re more likely to do it consistently and enjoy yourself. This guy is right on two counts.

Exercise is exercise, right? What difference does it make if I come to the gym to do deadlifts or swim laps? Heck, can’t I do even better for myself if I attend a barbell strength class and get my heart rate up WHILE LIFTING WEIGHTS? If this is where you’re at in your life, stop reading. You won’t take away anything more meaningful than a high five right now and I don’t want you to waste your time. (Insert high five here.)

But if you’re interested in knowing what the latest science is saying about the benefits of cardio versus weights, (so that you can work out smarter rather than harder) read on as we highlight what each form of training can do for you and your self-actualization.

Also, since it is possible to write an entire book on this subject, I will give you the Cliff Notes version of the most recent and impressive research.

Your Hormones

Every mammal on the planet has a very complex system of cholesterol-based molecules that float through your blood stream nonchalantly controlling several important biological functions. Hormones are so important, in fact, that we offer comprehensive Lab Testing to find out which of these systems needs work. Even with perfect nutrition and exercise programming, is these systems are not balanced, the body tends not to change. Even without testing, we know that the kind of exercise we do and how we do it can seriously impact hormones.

Weights. According to most current research, weight lifting takes the cake with regard to hormonal adaptations since it affects nearly all hormonal systems. But the two hormonal systems that differ significantly with weight training versus cardio are testosterone and growth hormone. Resistance training with varying sets, reps, rest periods and varying tempos activate the release of growth hormone and testosterone in both the young and elderly in bouts lasting shorter than 60min.[i] Testosterone is responsible for regulating a number of systems; most notably including blood sugar, fat metabolism, muscle growth, strength, and sex drive.[ii] You can think of growth hormone as the “fountain of youth” in the body since among many other functions, it restores and repairs all tissues, bone, muscle, organ, cartilage in the body when present![iii]

Cardio. This type of exercise affects quite a few hormone systems, but primarily insulin and cortisol. Cardio significantly affects your body’s responsiveness to insulin, which lowers risk of metabolic syndrome and allows more mobilization of fat stores to be used as fuel.[iv] Though proper weight training also affects this system, cardiovascular exercise has the added bonus of putting that fat burn into practice immediately! However, BE SMART about cardio programming because long bouts of mindless static cardio, especially in adrenally fatigued individuals,  causes a significant cortisol response that can break down muscle tissue and put undue stress on your vital organs.[v]

Your Brain

More and more of the exercise community are focusing less on the body composition benefits of fitness with regard to our most important organ. Though I have addressed how exercise affects the brain in previous writings, the type of exercise you do affects the benefits significantly.[vi]

Weights. The primary claim to brain-fame of weight lifting is the development of the cerebellum through learning new exercises. Most of your brain’s functions are routed through your cerebellum, which means changing things up in your resistance training routine with things like kettlebells and TRX can positively affect all aspects of your life through the development of new neural pathways in the brain.

Cardio. It’s cardio’s turn to take the cake here since it seems your brain was made to experience cardio on a regular basis. 30 minutes of cardio 3x/week can increase cellular resilience in the brain, diminishing anxiety-causing neurotransmitters and boosting serotonin output. This lowers symptoms of depression, improves baseline levels of dopamine and norepinephrine which gives you nearly super-human focus. And after a two hour lag post workout, increases your cognitive creativity![vii]

Heart and Lungs and Arteries Oh My!

Creating the junction between the circulatory system and respiratory system, the health of your heart, lungs, and arteries are responsible for providing the body with oxygen and other nutrients. The adaptation of these systems (or lack thereof) will greatly affect your risk of death and therefore medical costs, life insurance costs, and ultimately how many years you have to grace the world with your presence.

Weights. A strong weight lifting regimen can raise your HDL Cholesterol concentration, which is a positive cholesterol marker for heart disease prevention.[viii] Additionally proper weight lifting can affect heart disease indirectly as it may alleviate pain when used to correct posture or maladaptive movement patterns This removes common hang-ups people experience that keep them from doing cardio training.[ix]

Cardio. There is a reason this type of training is called “cardiovascular” training. Cardio training increases lung capacity, makes the heart stronger so it doesn’t have to work so hard with each beat, decreases blood pressure, improves blood lipid levels, and improves the efficiency of the body’s clearance of free radicals in the blood stream. [x][xi][xii] [xiii] Since cardiovascular disease is the leading cause of death in America (as well as the world), one economist estimated that 30-45 minutes of cardiovascular exercise each day would save us $30 billion/year in medical costs![xiv]

As you can see, the answer is not an easy one. Just with this brief overview of benefits, to answer such a question would require you to make a decision between coping better with stress or developing a better cerebellum. Do you choose raising HDL levels or strengthening the heart muscle itself? Do you want to live longer or live without pain?

I will not make these calls for you, but I will end this article knowing that you are well-equipped to add or take away weights or cardio depending upon what’s important to you!

An important note: All of these positive findings are based on good program design for both Cardio and Weight Training.

At Life Time, we recommend our members who are serious about their cardiovascular training get connected to our AMA 2.0 test to understand their cardiovascular metabolism, create a monthly workout program to guide their workouts, and experience a true interval training workout so they can be confident they are working SMARTER, NOT HARDER.

By the same token, we recommend our members who are serious about their weight training get connected with a fitness professional. With up to 5,000,000 variations of tempo, reps, sets, exercise selections, loads, times under tension, and body part splits, it can be overwhelming and difficult to settle on and execute the right kind of workout for your body. We can help you do that. Set up a free consultation today!

However you train, keep up the great work!

You deserve a high five!

[i]Craig BW1Brown REverhart J. Effects of progressive resistance training on growth hormone and testosterone levels in young and elderly subjects. Mech Ageing Dev. 1989 Aug;49(2):159-69.




[iii]  King MW (2006). “Structure and Function of Hormones: Growth Hormone”Indiana State University. Retrieved 2008-01-16.

[iv] TjØonna AE, Lee SJ, Rognmo Ø, et al. (2008). “Aerobic interval training vs. continuous moderate exercise as a treatment for the metabolic syndrome- “A Pilot Study””. Circulation 118 (4): 346–354. doi:10.1161/CIRCULATIONAHA.108.772822.

[v] Robergs R.A., Roberts S.O. Exercise Physiology: Exercise, Performance and Clinical Application. Mosby, St. Louis, 1997.

[vi] Dr. John Ratey’s Spark: The Revolutionary New Science of Exercise and the Brain.

[vii] Blanchette, David M., Ramocki, Stephen P., O’del, John N., and Casey, Michael S. (2005), Aerobic Exercise and Cognitive Creativity: Immediate and Residual Effects, Creativity Research Journal, 17(2&3), 257-264.

[viii] Ullrich IHReid CMYeater RA. Increased HDL-cholesterol levels with a weight lifting program.

South Med J. 1987 Mar;80(3):328-31.



[x]  Sharon A. Plowman; Denise L. Smith (1 June 2007). Exercise Physiology for Health, Fitness, and Performance. Lippincott Williams & Wilkins. p. 61. ISBN 978-0-7817-8406-1. Retrieved 13 October 2011.

[xi] Netburn, Deborah (March 30, 2009), “Dr. Kenneth Cooper got a nation moving through aerobics”Los Angeles Times

[xii] Wayne, Jake (14 June 2011). “Aerobic Vs. Anaerobic Fitness”. LIVESTRONG.COM. Retrieved 21 April 2013.

[xiii] Snowling, N. J., & Hopkins, W. G. (2006). Effects of Different Modes of Exercise Training on Glucose Control and Risk Factors for Complications in Type 2 Diabetic Patients A meta-analysis. Diabetes Care29(11), 518–2527.


The posts on this blog are not intended to suggest or recommend the diagnosis, treatment, cure, or prevention of any disease, nor to substitute for medical treatment, nor to be an alternative to medical advice. The use of the suggestions and recommendations on this blog post is at the choice and risk of the reader.
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