With the rise of CrossFit, methodologies that fit under the banner of metabolic conditioning such as super sets, complexes, and circuits are becoming more popular all the time. A recent study in the Journal of Strength and Conditioning Research took a glimpse at common components of these programs to see which were the most effective.
Study Design
To measure effectiveness of metabolic conditioning workouts, the researchers used oxygen consumption rates. Oxygen consumption correlates pretty well to energy consumption. The lion’s share of energy produced in the body is produced via aerobic methods, so greater energy expenditure requires greater oxygen consumption.
Measuring oxygen consumption isn’t a great way to detect anaerobic energy expenditure. Since a portion of any intense exercise will be anaerobic, the researchers also recorded oxygen consumption data during the rest periods for each tested exercise. Aerobic metabolism is often elevated after anaerobic exercise as a means of recovery (this is called excess post-exercise oxygen consumption, or EPOC). So in a roundabout way, the anaerobic energy was also partially recorded.
The researchers compared the oxygen consumption levels of thirteen common exercises. Traditional resistance exercises included the bench press, squat, lunge, and even the curl. Some bodyweight movements were added, like burpees, push ups, and planks. Exercises that used other implements were included as well, like Bosu ball push ups and battle ropes.
Comparing such diverse exercises can be difficult, so the researchers tried to keep the exercises close to how they are typically performed. This means some of the weighted exercises and more intense bodyweight moves, like the bench press and burpees, were done for three sets of ten, with about 75% of the participants’ one rep maxes. The less intense bodyweight moves like push ups were performed with three sets of twenty. The ropes and planks were done for three sets as well, but for a time of thirty seconds. All exercises had two-minute rest periods in between each set.
Each one of these exercises were performed in a random order on different days. Only one exercise was done per day so the researchers could get a reading that wasn’t altered by a previous exercise.
Results
Take a guess at what you think would be the most effective at burning calories. If you guessed burpees and battle ropes, you got it right. After converting the oxygen consumption to calorie expenditure, the battle ropes scored an average of 10.3 calories per minute, and the burpees came in at 9.6 calories burned.
To put these results in perspective, the participants burned 1.1 calories per minute when resting. The squat protocol averaged 8.2 and was the highest of the resistance exercises. The only other move that exceeded eight calories per minute was the push up with a lateral crawl, coming in at 8.1 calories burned. Dead last were planks, at a mere 3.3 calories per minute. But of course, even doing planks burned over three times more calories than doing nothing.
Now obviously if you adjust the weights used, the rest periods, the speed of the moves, and other variables, you will get different results than they got in this study. Try these exercises out as prescribed and then play with the numbers to see how it changes the feel of each move. And if you’ve been using ropes, keep it up, because they work.
References:
1. Nicholas Ratamess, et. al., “Comparison of the Acute Metabolic Responses to Traditional Resistance, Body-Weight, and Battling Rope Exercises,” Journal of Strength and Conditioning Research, DOI: 10.1519/JSC.0000000000000584
Photo courtesy of CrossFit Impulse.
