The Truth on Cardio: Steady State, HIIT, Muscle Gains, and Fat Loss.

Posted: January 27, 2015 by TRU in Fitness, Physique
Tags: , , , ,

Arnold Jog

The physique enthusiast’s guide to cardio

Trying to write a guide on this cardio business was quite an enduring feat. While I had hoped it was going to be short and sweet, much like a HIIT session, it somehow ended up being more of a marathon…ok maybe a half-marathon. In any event, whether you’re a physique enthusiast currently avoiding cardio, a veteran gym-goer who religiously does cardio, or a newbie who is just thinking of starting, start here and save yourself some time and potentially wasted effort. This is The Truth on Cardio.

Disclaimer: the content of this article is for informational purposes only and is not medical advice.

Low Intensity Steady State Cardio (LISS)

When most people think of cardio, they’re usually thinking of steady state cardio (LISS). In other words, walking, jogging, or running at a relatively low speed and maintaining that speed for a period of time. Imagine a person who gets on a treadmill, adjusts the speed to 6mph, and continuously jogs at that speed for 40 minutes; this is an example of LISS. LISS is the most researched form of cardio and tends to be the “doctor recommended” variety; with many probably not even realizing there are actually other ways to do cardio.  All jokes aside, steady state cardio does offer a variety of benefits from general health to fat loss (see table below) and is very easy to implement, e.g. just start jogging and keep going until you’re too tired to continue.

10 Benefits of Cardio

Improves Sleep Reduces risk of heart disease
Supports fat loss* Reduces risk of certain forms of cancer
Improves muscle mass* Reduces risk of osteoporosis
Improves insulin response Reduces stress, depression, and anxiety
Improves blood cholesterol and trigylcerides Strengthens the immune response

*physique enthusiasts beware. More details below.

 From the table above you might start to think that LISS is the answer to all your fitness prayers. But before you go out and buy a treadmill, a mistake that is easy to make is that simply because LISS can help with the items in the list above doesn’t mean LISS is the BEST way to improve these items. For example, if a couch potato starts jogging consistently, after several weeks the muscles in his calves will likely have grown (hypertrophied) in response to the new physical stress of jogging. Thus, it wouldn’t be wrong to conclude that LISS increases muscle mass, even though in reality LISS is a poor choice for increasing muscle mass compared to something like weight training. While this is probably obvious to most of you, it can be more difficult to realize when it comes to some of the other listed benefits like fat loss; hence the continued mainstream belief that cardio is essential for fat loss…but let’s get back to muscle.

Cardio Will Shrink Your Muscles, Bro!


Many lifters would have you believe that just thinking of doing cardio will make you look like this guy

LISS has gotten somewhat of a bad rap in bodybuilding circles, with many under the impression that excessive or even any cardio will shrivel their muscles, sap their strength, and prevent them from ever having children (ok I made up the last one). There is some truth to this, though much of the research used to back up these claims has mostly been short in duration; with many studies being less than 12 weeks. This means we don’t really know if your muscles can adjust/compensate for the initial decline in muscle mass over time. Furthermore, some of these claims are based on chronic adaptations of elite endurance athletes who rarely also weight train intensely, which we know helps reduce some of the loss in muscle size associated with LISS. Case in point, whether or not a person who has both weight trained and LISS for many years would have significantly less muscle mass than if he had only weight trained is still up for debate.

zane posing

Interestingly enough, many bodybuilding favorites of the golden era such as Arnold and Frank Zane could often be spotted out on a jog, and while it is true that they used anabolic steroids (which you could argue prevented them from experiencing the muscle wasting effects of cardio), one thing is clear; they still had enough muscle to step onto the podium among other guys who didn’t do much if any cardio (Serge Nubret). Furthermore, the physiques of the golden era looked far more aesthetic than the muscle bound cartoons we call bodybuilders today. Yes there are several reasons for these differences, such as the more recent use of HGH, but there could be something to this cardio component enhancing the physique…just a thought.

The research suggests that for LISS to negatively impact your progress in the weight room and also in front of the mirror, you’d likely have to do more than your average gym rat (upwards of 30 min more than 3x/week; although everyone will be slightly different so experiment accordingly). On the other hand, for most trainees a couple 20-30 minute LISS sessions each week will likely do more good than harm (retain muscle mass while promoting some additional fat loss). If there is a time to really be concerned about the negative effects of LISS, it is during a caloric deficit (when cutting calories) as you will be more likely to lose some of your precious muscle mass during a hypocaloric state. Luckily, this effect is less common with HITT!

The Skinny on LISS

vintage TM

The majority of Americans, and the rest of the westernized world for that matter, still continue operate under the spell that fat loss takes place while jogging on a treadmill. But what does the evidence have to say about this? A recent study published in the Obesity Journal analyzed fitness habits of 10,500 people over 12 years and found that those who consistently weight trained had less abdominal fat than those who only did cardio (while those who did both had the best results). And while you can argue that this wasn’t a perfect study, it also wasn’t the first study to question the idea that cardio is BEST for fat loss. So if the overarching theme of our current body of evidence is suggesting that cardio isn’t best for fat loss, why are gyms still devoting excessive amounts of square footage for cardio treadmills? I’m glad you asked.

Fat man on bike

In fact, the most dramatic loss in fat mass occurred from moderately high to very high intensities (Wilson, 2012)

Furthermore, from a purely observational standpoint, it isn’t an uncommon sight to see overweight and obese people running in and completing half and full marathons. Obviously training for a marathon requires a decent amount of consistent LISS, yet somehow these obese marathoners are managing to cross the finish line just in time for lunch. On the other hand, if you walk into an ordinary weight room, you’ll likely notice that a greater percentage of the people lifting weights tend to be in somewhat decent physical shape, with a smaller percentage being overweight/obese than those at the marathon. Clearly there are several reasons why this may be, and yes there are many flaws to this example, but a growing body of evidence is beginning to show that this observation might be more than just coincidental.

Did you know? Hardgainers are often advised to avoid cardio like the plague, though it is not unusual for LISS to actually increase appetite (swimming for example). In other words, some cardio might actually help with weight gain. Who would’ve guessed?



Nice hit! …not to be confused with HIIT

What is HIIT? HIIT stands for High Intensity Interval Training. There are countless ways to HIIT but essentially you just want to have periods of lower intensity varied with periods of higher intensity. HIIT sessions tend to be shorter in duration than LISS sessions due to the increased physical demand/fatigue from the high intensity component. To reap the benefits of HIIT you should be spending at least 10minutes a few times each week, preferably at least six hours apart from your weight training sessions if done on the same day (to minimize interference). HITT sessions can certainly run longer than 10 minutes, but if you’re already weight training intensely most days of the week, overtraining can more easily result, so proceed with caution.

Bon Appetite! Fasted cardio isn’t holding up to scientific scrutiny (no better for fat loss than “fed cardio”) although more research is needed. In the meantime, stop torturing yourself if cardio on an empty stomach makes you feel like crap.


Over the Top

HIIT vs. LISS, another battle showing that sometimes less can actually be more

I’m sure you just want to know which is BEST right? Well of course I’m going to say, that depends. I will also say that aside from marathoners and other athletes who need to perform at a lower intensity for extended periods of time, most athletes, bodybuilders, and weekend warriors who just want to look better naked would be wise to devote at least some of their cardio to HIIT. HIIT has been shown to increase the body’s ability to use fat for fuel more effectively, which could amount to a visible difference over an extended period of time e.g. 1 year or more.

What is also promising about HIIT is that it tends to be more efficient than LISS, and equally if not more effective in some regards (HIIT sessions pack quite a physiological punch). Furthermore, HIIT sessions may have better carry over to your weight training sessions since weight training is a high intensity interval of its own. Translation, HIIT is not only less likely to diminish muscle size and strength than LISS, it may also make your strength training workouts even better.


Code Blue Alert! Surprisingly, HIIT may actually be as good if not better for patients with heart failure and pre-existing heart conditions than LISS (Wisloff, 2007).

HIIT + LISS…are you for real??  

LISS can actually be a nice HIIT supplement. What do I mean? Rather than extending a HIIT session and risking overtraining/delayed recovery between your next strength training workout, why not begin with HIIT and then continue with LISS for the remainder of the session? For example:

5 min walk (3-3.5mph) + 10-15 min HIIT (1:1 or 1:2 work to rest ratio) + 15-20 min LISS (jog 5-6mph)

(1:1 work to rest ratio sample: 30s high intensity cycling alternated with 30s mild cycling for 10 min)

(1:2 work to rest ratio sample: 30s high intensity cycling alternated with 1 min mild cycling for 10 min)

This amounts to a 30-40 minute cardio session. Moreover, it shortens the actual amount of LISS time, meaning you’ll be even less likely to suffer from any potential muscle/strength loss associated with LISS. I’d still recommend aiming for the lower end if you are concerned about over training/physique enhancement and the higher end for those looking more for conditioning/general fitness. Don’t forget that this is a process that will take some trial and error, but the above should serve as a decent starting point. If you’re new to HIIT and already weight training regularly, start with one to two cardio days (HIIT/LISS) each week for a few weeks and progress or regress accordingly.

Rule of Thumb: If you’re still making solid progress in the weight room that’s generally a good sign that you’re not overtraining. Train on!




Increased recovery time=Greater tendency to over train if combined with intense strength training Less recovery time/can perform more frequently
More time efficient: decreased training duration Less time efficient: increased training duration
Fat loss effects: (fair+)Less calories burned during sessionMore calories burned after session (↑ EPOC) Fat loss effects: (fair)More calories burned during sessionLess calories burned after session
Increases muscle mass (poor+)Less likely to decrease muscle mass, strength, and power Increases muscle mass (poor)May decrease muscle mass, strength, and power (when done for extended periods of time)
May suppress appetite Neutral/May increase appetite
Not as easy to implement (initially)Requires more planning/programming Easy to implement
Awkward/dangerous on certain machines (treadmill) Compatible with most cardio machines


 In Summary: Know the Role!

In the end, personal preference is perhaps the biggest consideration in the HIIT vs LISS comparison. In case it hasn’t become obvious by now, realize that neither HITT nor LISS are the best tools for building muscle or losing fat. That’s what progressive weight training and eating a proteinaceous vegetable laden diet are for! Thus, the role of cardio(HITT or LISS) for the physique enthusiast is mainly to compliment your training while establishing a solid level of cardiovascular fitness and general health. That being said, HITT may have a slight advantage as long as you don’t go overboard (allow it to delay recovery and interfere with your weight training workouts). LISS on the other hand, may be the preferred choice for newcomers who don’t yet have a decent strength/training foundation, those who have orthopedic issues, or those who just love to LISS. So know what role cardio plays in the overall fitness picture and use it accordingly. That being said, don’t attempt to use cardio for the things it doesn’t do very well…cause ain’t nobody got time for that!

Whether it’s HIIT or LISS (or some combination), some cardio belongs in most every physique enthusiast’s tool chest. Get er done!




  1. Alkahtani, SA. et al. Acute Interval Exercise Intensity Does Not Affect Appetite and Nutrient Preferences in Overweight and Obese males. Asia Pac J of Clin Nutr. 23(2).
  2. Astorino TA, Schubert MM. Individual Responses to Completion of Short-Term and Chronic Interval Training: A Retrospective Study. 2014. 9(5)
  3. Boutcher, S., Dunn, S. Factors that may impede the weight loss response to exercise-based interventions. Obesity Reviews. 2009. 10(6). 671-80.
  4. Erdmann, J. et al. Plasma Ghrelin Levels during Exercise—Effects of Intensity and Duration. Regulatory Peptides. 2007. 143(1): 127-135.
  5. Gaesser, GA., Siddhartha SA. High-Intensity Interval Training for Health and Fitness: Can Less Be More? J of App Phys. 111(6). 1540-41.
  6. Gibala, MJ. McGee, SL. Metabolic Adaptations to Short-Term High-Intensity Interval Training: A Little Pain For a Lot of Gain? Ex and Sport Sci Rev. 2008 36.2: 58-63.
  7. Gillen, JB., Gibala MJ. Is High-Intensity Interval Training a Time-Efficient Exercise Strategy to Improve Health and Fitness? App Physio Nutr and Metab. 39(3). 409-412.
  8. Gurd, BJ., et al. High-Intensity Interval Training Increases SIRT1 Activity in Human Skeletal Muscle. App Physio, Nutr, and 2010. 35(3), 350-57.
  9. Larson-Meyer, D. Enette, et al. Influence of Running and Walking on Hormonal Regulators of Appetite in Women. J of obesity 2012
  10. Lo, M., et al. Training and Detraining Effects of the Resistance Vs. Endurance Program on Body Composition, Body Size, and Physical Performance in Young Men. Journal of Strength and Conditioning Research. 2011. 25(8), 2246-54
  11. Macpherson, RE, et al. Run Sprint Interval Training Improves Aerobic Performance But Not Maximal Cardiac Output. Med and Sci in Sports Exer. 2011 43(1), 115-122.
  12. Martins, C. et al. Effect of Moderate-and High-Intensity Acute Exercise on Appetite in Obese Individuals. Med and Sci in Sports and Exer. 2014.
  13. Ronnestad, B., et al. High Volume of Endurance Training Impairs Adaptations to 12 Weeks of Strength Training in Well-Trained Endurance Athletes. Eur J of App Physio. 2012. 112, 1457-1466
  14. Rosenkilde, M., et al. Body fat Loss and Compensatory Mechanisms in Response to Different Doses of Aerobic Exercise. Amer J of Physio. 2012. 303(6): 571-577.
  15. Schoenfeld, B, Dawes, J. High-intensity Interval Training: Applications for General Fitness Training. Stren & Cond J.31(6): 44-46.
  16. Sillanpää, E. et al. Body Composition, Fitness, and Metabolic Health During Strength and Endurance Training and Their Combination in Middle-Aged and Older Women. Eur J. of App Physio. 2009. 106(2): 285-296.
  17. Skelly, LE., et al. High-Intensity Interval Exercise Induces 24-h Energy Expenditure Similar to Traditional Endurance Exercise Despite Reduced Time Commitment. App Physio Nutr and Metab. 2014. 39: 1-4.
  18. Talanian, Jason L., et al. Two Weeks of High-Intensity Aerobic Interval Training Increases the Capacity for Fat Oxidation During Exercise in Women. J of App Physio. 2007 102(4), 1439-1447.
  19. Townsend JR, Stout JR, et al. Excess Post-Exercise Oxygen Consumption (EPOC) Following Multiple Effort Sprint and Moderate Aerobic Exercise. Kinesiology. 2013; 45(1), 16-21.
  20. Trapp, EG., et al. The Effects of High-intensity Intermittent Exercise Training on Fat Loss and Fasting Insulin Levels of Young Women. Int J of Obesity. 2008. 32(4), 684-691.
  21. Weston, KS, Wisloff U, Coombes JS. High-intensity Interval Training in Patients with Lifestyle-Induced Cardiometabolic Disease: A Systematic Review and Meta-Analysis. Brit J of Sports Med
  22. Wilson, J., Marin, P., et al. Concurrent Training: a Meta-Analysis Examining Interference of Aerobic and Resistance Exercises. Stren & Cond J. 2012. 26(8), 2293-2307
  23. Wisloff, U, et al. Superior Cardiovascular Effect of Aerobic Interval Training Versus Moderate Continuous Training in Heart Failure Patients a Randomized Study. 2007. 115.24: 3086-3094.

Leave a Reply

Your email address will not be published. Required fields are marked *