Back when we were younger, the idea of “exercise” was easy. We played kickball in gym class, ran track or played on the baseball team. When we got a bit older, exercise became weekend soccer, long walks or light runs, and playing golf (walking the course, of course!).
So when did exercise become complicated? Now it seems like people are telling us we have to do aerobic exercise for our hearts and waistline, resistance training for our bones and muscle strength, and stretching for, well, everything. And in an age of the “miracle pill,” is it any wonder people aren’t exercising at all?
Of course, the answer is that you do need to do a bit of all three for maximum health. Or do you? According to one study, you may be able to get the same stretching benefits from a well-designed resistance training program.
Move It or Stretch It?
Researchers divided 36 volunteers into three groups. One group did resistance exercises, the second group did stretches, and the third group remained inactive.
The resistance group did strength-training exercises three days a week for five weeks. Each training session lasted 45 minutes to an hour and included a five-minute warm-up on a stationary bike.
Their specific training included 20 different exercises that worked all body muscle groups, focusing on different areas on different days. They did not stretch as part of their workout and were asked to refrain from any stretching during the five weeks.
The stretching group also exercised three days a week for five weeks. Each session lasted about 30 minutes and included 13 different stretches, all of which were done during each workout. They were asked to refrain from any other exercise, particularly strength training, during the five weeks.
Additionally, all three groups were tested before and after the study period to determine both strength and flexibility capabilities. Specifically, they were tested on:
- Knee extension flexibility
- Hip flexor flexibility
- Hip extension flexibility
- Shoulder flexibility
- Hamstring and quadriceps strength
At the end of the five weeks, researchers found that both groups demonstrated greater knee and hip flexibility than the inactive group, which you would expect. However, there were no significant differences in flexibility between the resistance and stretching groups. Or, to say it another way, both exercise groups gained comparable flexibility in their knees and hips.
When it came to shoulder flexibility, there was not a significant difference between any of the groups. Ditto for hamstring strength.
But this was not the case for quadriceps strength. There was a significant difference in strength between the resistance group and the inactive group. However, there was no significant difference between the stretching group and the inactive group, or between the stretching group and the resistance group.
Now, on the surface, that may seem confusing or nonsensical, so let me explain.
If the inactive group had a -2 ft/lb change and the resistance group showed a 7 ft/lb change, that’s a difference of 9 ft/lb, which is pretty significant. Now, if the stretching group had a 3 ft/lb change, that’s a 5-point difference from the inactive group and a 4-point change from the resistance group … not as significant.
Make Resistance Training a Must
Given these results, researchers concluded that full-range resistance training may improve flexibility as much as traditional stretching exercises, at least when it comes to short duration time periods. And, if these results are replicated over a longer time period with a greater number of participants, “the implications to coaches and exercise leaders are of obvious importance.”
I would extend that beyond coaches and trainers to the average Joe. Most of us are crunched for time and knowing that 45 to 60 minutes of resistance training three days a week provides not just added strength, but also greater flexibility is music to my ears.
If you are unfamiliar with strength training, don’t go into it blind. You can invest in a few sessions with a trainer to get you started and help you create a solid plan to work all muscle groups. There are also many DVDs on the market that walk you through different resistance exercises. Additionally, many gyms offer weight-training classes as part of their monthly fee.
 Morton, SK et al. Resistance training vs. static stretching: effects on flexibility and strength. J Strength Cond Res. 2011 Sep 30. [Epub ahead of print.]