A word or two on cardio
For what seems like a million years, we’ve been told that “cardio” will make us lean and healthy. Doctors told us our cardiovascular health depended on it. Pop-culture magazines touted “walk the weight off” programs that were easy-peasy. Steady state, low-impact, low-intensity cardio was what we all needed to look wonderful and live forever.
Then, a few people in the fitness world started to ask “if long-duration, steady state cardio is so good for us, why are all those people still soft, weak and sick (and mostly overweight?)”
Good question…and one of many.
Another one: if steady state cardio is the way to lose body fat and get lean, why do sprinters and people who lift weights (with virtually NO steady state cardio) look so lean, muscular and, well, sexy?!?
Because steady state cardio is crap. Period.
Now, if you are a runner, triathlete or any other kind of distance/extreme sport enthusiast, relax. You love to run, bike or swim (or all three) for a really long time, I get that. I’m not talking about you.
I’m talking about the 3-5-days-a-week-for-an-hour-at-the-same-speed-because-it-said-so-in-my-magazine crowd. The people who do the same cardio routine day in and day out.
And their bodies never change. Not a bit.
Want proof steady state cardio is a giant FAIL? Here you go:
Redman et al. Effect of calorie restriction with or without exercise on body composition and fat distribution. J Clin Endocrinol Metab. 2007 Jan 2.
In this study in futility, the subjects did 45 minutes of cardio a day, 5 days a week and lost no more weight than those who ONLY dieted! Bored into submission for nothing!
Oh, that one was an accident, you say? Okay, let’s try again:
Utter AC, et al. Influence of diet and/or exercise on body composition and cardiorespiratory fitness in obese women. Int J Sport Nutr. 1998 Sep;8(3):213-22.
Here the poor saps did 50 minutes of cardio, 5 days a week and nada! No more weight loss than the dieters who didn’t waste 50 minutes a day!
So what would most people do? MORE! More is better, right? Wrong! Check it out here:
McTiernan et al. Exercise Effect on Weight and Body Fat in Men and Women. Obesity 2007 June – 15:1496-1512.
60 minutes a day, 6 days a week for an entire YEAR! Average weight loss?
3.5 pounds. In an entire year of I’m-so-bored-I-could-puke cardio repetition.
A year those people can never get back.
But as mentioned, there is a much better alternative, and that alternative lies in short, intense bouts of exercise.
In fact, a recent study published in the European Journal of Applied Physiology found that 15 minutes of a circuit-style resistance training workout elevated metabolism for a full THREE days! And that’s only from 15 minutes!
Other studies have found similar results with interval style workouts as short as 4 minutes producing dramatically more fat loss than long, extended bouts of cardio.
There are even entire fitness franchises built around increasing intensity and reducing total time. After millions of years of human movement and over a century of organized discussion about exercise, training and related subjects, we’re finally getting some common-sense, results-driven options.
Lots of training studios and fitness centers have switched out to 30 minutes sessions, with higher intensity. And it works. It works because consistency, not length of workouts or how hard you go, is really the key to long-term, sustainable fitness and health.
In fact, in a recent study, researchers found that high intensity bouts of exercise lasting just 2 total minutes can be as effective as exercising at a moderate intensity for 30 minutes!
Here’s the details on the study, detailed in the press release.
“A few minutes of high-intensity interval or sprinting exercise may be as effective as much longer exercise sessions in spurring beneficial improvements in mitochondrial function, according to new research. The small study is published ahead of print in the American Journal of Physiology — Regulatory, Integrative and Comparative Physiology.
Mitochondria, the energy centers of the cells, are essential for good health. Previous research has found that exercise creates new mitochondria and improves the function of existing mitochondria. Altered mitochondrial function in response to a single session of exercise generates signals that may lead to beneficial changes in the cells, lowering the risk for chronic disease. High-intensity interval exercise consists of short bursts of high-intensity aerobic exercise — physical activity that raises the heart rate — alternating with brief recovery periods. Whether the intensity of a workout affects mitochondrial response is unclear.
A team of researchers studied eight young adult volunteers as they participated in cycling workouts of varying intensity.
- Moderate intensity consisted of 30 minutes of continuous exercise at 50 percent peak effort.
- High-intensity interval exercise consisted of five four-minute cycling sessions at 75 percent peak effort, each separated by one minute of rest.
- Sprint cycling consisted of four 30-second sessions at maximum effort, each separated by 4.5 minutes of recovery time.
The research team measured the amount of energy the volunteers spent on each workout and compared mitochondrial changes in the participants’ thigh muscles before and after each exercise session. The researchers found that levels of hydrogen peroxide — a type of molecule involved in cell signaling called “reactive oxygen species” that contains oxygen and hydrogen — in different parts of the mitochondria change after exercise. While too much reactive oxygen species can be damaging to the cells, the researchers noted that the volunteers’ levels were an appropriate amount to potentially promote cell responses that benefit metabolic function rather than cause damage.
In addition, the research team found that fewer minutes of higher-intensity exercise produced similar mitochondrial responses compared to a longer moderate-intensity activity. “A total of only two minutes of sprint interval exercise was sufficient to elicit similar responses as 30 minutes of continuous moderate-intensity aerobic exercise,” the researchers wrote. “This suggests that exercise may be prescribed according to individual preferences while still generating similar signals known to confer beneficial metabolic adaptions. These findings have important implications for improving our understanding of how exercise can be used to enhance metabolic health in the general population.”
So, it seems that unless your goal is to be able to keep jogging, swimming, walking or cycling for a really long time, your best fitness results might come from a program based on intensity and total output, rather than time.
All of this being said, I do recommend that my clients do 20-30 minutes of walking every day. In theory, we could call that cardio, but the real point of that is to connect with the outdoors, create some metabolic stability and help them manage stress while burning a few calories.
Cardio as it has been sold to us by doctors, the government and treadmill, stationary bike and elliptical trainer makers, however, should be humanely put down, in my humble opinion.
Just more to think about.
Keep the faith and keep after it!
Journal Reference – Adam James Trewin, Lewan Parker, Christopher S. Shaw, Danielle Hiam, Andrew P. Garnham, Itamar Levinger, Glenn K. McConell, Nigel K. Stepto. Acute HIIE elicits similar changes in human skeletal muscle mitochondrial H2O2 release, respiration and cell signaling as endurance exercise even with less work. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 2018