Not every client will want to get stronger or better at cardio. Some might want to be healthier by reducing inflammation or minimizing diabetes risk. In a recent study in the Journal of Strength and Conditioning Research, these exercise goals were examined in detail.
While some research has been done to determine the effects of exercise on biomarkers of inflammation and metabolic disorders, what is less understood is where our time is best spent. Exercise has been shown to been effective at reducing these disorders all on its own (even without dietary changes), but which type works the best and on what specific markers is where the questions lie.
Interleukin-10 and interleukin-20 are two related cytokines that have anti-inflammatory functions. In medicine, they are sometimes used as markers of inflammation. Where there is more inflammation, there will be more anti-inflammatory substances like these interleukins, so they were chosen for this study as factors to determine inflammation.
Another substance the researchers chose to examine was tumor necrosis factor alpha (TNF-a). TNF-a was chosen because it plays a role in inflammation and also contributes to insulin resistance. Insulin resistance is not good for athletes or non-athletes alike, and is a warning sign of metabolic disorders like diabetes. The researchers also studied insulin resistance directly, VO2 max, strength, and a host of other anthropometric values.
The study focused on determining what exercise programs were best for fighting inflammation and metabolic disorders. The researchers analyzed each of these factors in a group of middle-aged, obese men, which is a common client you may see. They split the participants into three groups. One was a control group that made no changes, and the other two performed two different exercise protocols for twelve weeks. Each workout was done three times per week.
One of the workouts was a weight training regimen using standard exercises like deadlifts, bench presses, and curls. The intensity varied from workout to workout, using anything from twenty-rep sets all the way down to three-rep sets, and it lasted generally for 40-65 minutes.
The other workout was an aerobic interval cardio plan consisting of four sets of four-minute intervals at eighty to ninety percent of maximum heart rate. The rest periods in between the intervals were at 55-65% of the participant’s max heart rate. Unfortunately, there was no mention of how they determined the max heart rate, but it doesn’t appear as though this was something they tested directly. If they used a simple age calculation, the low end of the interval might be in the 140s for a heart rate, which is not especially taxing.
Despite only sixteen minutes of moderate-paced running, interspersed with much lighter work, the aerobic intervals outperformed the resistance training by a small margin. The aerobic group improved one measure of the inflammation markers significantly versus none for the resistance group. Both groups improved VO2 max, with the aerobic group edging out the resistance group. Both programs made a similar, but major improvements to insulin resistance and insulin levels.
Ultimately, with the routines used here, twelve weeks of mild aerobic exercise is slightly better for inflammation than resistance work. However, two things are for certain. First, the cardio plan used in this study was pretty light, and should subsequently be improved. Second, the best benefit would probably have been achieved by doing both strength training and cardio.
References:
1. Mahmoud Nikseresht, et. al., “Effects of nonlinear resistance and aerobic interval training on cytokines and insulin resistance in sedentary obese men,” Journal of Strength and Conditioning Research, DOI: 10.1519/JSC.0000000000000441
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