Why Cardio is NOT a Waste of Time

By Mike Howard

“Cardio is useless, a waste of time, it eats muscle, it’s boring….” The majority of fat loss experts are now swinging away from long slow distance type cardio as part of a weight loss intervention and overall health.

In theory (and it would seem in practice, too), the concept of HIIT (High intensity interval training) as a superior method for blubber-burning is valid. But is the pendulum swinging too far?While the literature, the forward-thinking fat loss experts and my own personal/professional experience side with the weight training/intense cardio mentality – there are limitations and caveats to this school of thought. Here’s what I think.

  • The people that need to boost their health and lose fat the most need to establish a cardio-respiratory base. Trying to push an unfit individual to their physical extremes can be dangerous. Furthermore, physical discomfort is not conducive to continuing an activity and therefore long term success.
  • High intensity training requires rest. Even if you are at a higher physical level, interspersing longer, slower cardio into your routine is advisable.
  • Interval training does not have to be intense. In fact, you can incorporate intervals with the even the most unfit individuals.
  • You can still mix it up. You can perform longer, slower distance cardio on different modes (ie. treadmill, bike, elliptical) and even incorporate intervals on those modes.
  • Longer, slower cardio still burns calories. It still exercises your heart and lungs and it still helps stave off many diseases and ailments.
  • Once you’ve established a good cardio base, incorporating more intense cardio is warranted. Be sure you are mentally prepared for such efforts
  • Long, slow cardio or intense cardio in the absence of weight training will limit the benefit of fat burning.

Bottom Line

It becomes easy to get carried away with the “method A is superior to method B” mentality. There is certainly an advantage of doing HIIT-type training vs. long, slow distance cardio when it comes to effectiveness and efficiency.

I believe, however that it needs to be progressive and integrative and that we have to rid ourselves of the mentality that longer, steady state cardio is useless. This type of activity can be monumentally beneficial for those who need it the most.


  1. Nick

    The implicit assumption with this reasoning is that athletes look the way they do because of their training, which is somewhat flawed. You can take any of these muscle-bound sprinters and train them for a marathon and they’re not going to look a whole lot different. Likewise, you could train a skinny marathoner for sprints and he/she isn’t going to start looking like a muscular Olympic sprinter. These elite athletes are born for their event with certain bone structures and genetic tendencies. For amateur sports you get a wide range of builds as the other poster noted. Excess muscle on long-distance runners weighs them down and wastes oxygen.

  2. turbo

    I suggest you read his post again. He says that the only organs that *require* glucose is limited. This is correct.

    Of course, glucose is important for the brain, but when subjected to a low carbohydrate diet, the body compensates by producing ketones. This supply added to the glucose that your body synthesizes from other sources (like proteins) is enough for your body.

  3. Charles

    I have seen the pendulum swinging too far to the super intense recommendations.

    Partly because the people who are the loudest fitness promoters are 20 year old athletes and personal trainers. When I was a 20 year old athelte I was lifting everyday, sprinting and jumping, doing cardio, and walking or riding my bike all over Boston.

    Now, that I have a little more perspective I realize that almost everyone over 25 has joint issues like knee pain or back pain which makes it hard to train at high intensities.

    HIIT is only for fit people with great joints, so it has limited appeal.

    I once worked with a 350 pound woman, and she would be out of breath after 2 minutes on a stationary bike with no resistance.

    I like HIIT for people who can do it, but the reality is that a lot of people can’t do it.

  4. Registered User

    I suggest you read biology text books. Every cell in you body uses glucose. It is the raw product in cellular respiration.

  5. hoodoo

    Not true. I suggest you read some exercise physiology text books. The only tissues that require glucose are the brain, eye and red blood cells. The total amount of glucose needed is only around 60g per day. Glucose can be created as needed from protein (but not fat). The average male has around 400g of glycogen stored in the liver and another 100g in the muscles. This is sufficient for around 90 minutes of very high intensity exercise. It is enough for a whole day of moderate activity such as jogging. Only elite athletes involved in continuous high intensity activities (eg elite marathon runners) can exhaust these glycogen stores. Cardio training makes the body utilise fat in preference to glucose at higher levels of exertion.

    The other energy source very rarely mentioned is ketones. they are produced by the metabolism of fat. Ketones are metabolised more efficiently than glucose, The body can use ketones interchangeably with glucose.

    The primary energy source for the body is fat. It is used in all low and moderate intensity activity. The only time you will use glucose is in higher intensity activities such as running. Unless you have a high cardio fitness level you will be unable to burn glucose for more than a few minutes before becoming exhausted.

    Just because athletes have high carbohydrate diets doesn’t mean anyone else should. The vast majority of what athletes do has no solid scientific evidence to support it. For example there is no valid experimental evidence at all to support warm-ups or stretching but all athletes do it.

    Humans have evolved to do around 4-6 hours per day of brisk walking. You can’t replace that by doing two or three short high intensity sessions per week.

  6. Razwell

    To Modern Forager

    The sprinter vs martahoner argument is a FALLACY. Lyle McDonald TEARS it to shreds.

    75 % of an elite Olympic sprinters tyraining is at LOW intensity. Sprinters, when they do sprint (whioch does not comprise that much) it does not even remorely resemble HIIT – AT ALL.

    Completely different rest times.

    The MAIN difference is sprinters LIFT. They got that way LIFTING and TOTAL TRAINING VOLUME , 75 % of whcih is LOW intensity.

    Another HIIT promoter……..

  7. martyn

    I lost weight after trying lots of methods by using a military fitness method that worked better for me than for anything else iv tried. You can read my story and check it out for yourself at

  8. Lady G

    Great to have this discussion and bring the issues to light. Like most things in life, I think it’s not a matter of one or the other when it comes whether cardio, HIIT, or weights is most important – it’s somewhere in between – a balanced mixture of everything is important!
    Unfortunately sometimes it’s easier to stuck on the one thing we love!

  9. Robert Mayer

    The heart (and lungs, for that matter) is a muscle like any other. You can train it in different ways for different things. I think there is a certain benefit to long, raised heart rate that contributes to cardiovascular endurance in a way that HIIT doesn’t match the same way.