A few weeks ago over at Precision Nutrition, a couple of hacks named "John Berardi" and "Alwyn Cosgrove" put together an impromtu study of about 60 exercisers; their intention was to compare the weight-loss/performace-enhancement effects achievable through three different training protocols:  strength training plus steady-state cardio; strength training plus sprint intervals, and strength training plus suspension training ("TRX") circuits.

(No fat on this cat.) 

The strength-training routine performed by all three groups was the same:  twice a week, full-body workouts consisting of the heavy-hitter moves dones in the strength/hypertrophy rep range.  Standard-issue, road-tested, and effective.  The conditioning workouts varied, however:  two additional days a week, one group did steady-state cardio, another did sprints, another more TRX work.  You can read about their results here.

Subjects were tested at the beginning and again at the end of the study in a maximum push-up test, an inverted row, test, a standing broad jump test, and the V-max, and T-max tests on a treadmill, both indicators of aerobic and anaerobic fitness. Their weight was also recorded.

At the end of the study there was very little difference among the three groups in the tests of strength and power (push-ups, inverted rows, and standing broad jump).  The steady-state cardio group, however, had a significant edge on the T-max test (which is performed on a treadmill and described at the link above), and the TRX group had a big edge on the 'attrition' category:  something like 80% of the steady-staters weren't steady enough, and 55% of the sprinters turned tail and ran, but only 35% of the TRX'ers suspended their involvment, so to speak.

One clear--perhaps unintended--lesson is that no one wants to do steady-state cardio, and that, conversely, people like working on the suspension trainer.  That might not seem important, but there's something to be said for that:  I mean, anyone can lose weight by doing hard labor all day and eating nothing but cranberries for six weeks, but the program will suck so much that you won't want to do it, and you'll drop out.  So it's no small thing to find a system that a majority of people will stick with, and Berardi is right to point that out.

If you'd asked me eight weeks ago how these results would shake out, though, I probably would have wagered that the TRX folks would improve the most on the body-weight training tests, the sprinters would do the best on the tests of aerobic and anaerobic fitness, and the steady-staters would have little improvement across the board due to the "interference effect" of adding steady-state cardio to strength training.  

So I'm surprised that the TRX folks DIDN'T get better push-up, inverted row, and broad jump results over the eight weeks, even though they were doing much more body-weight style training than the other groups; I'm surprised that the sprinters didn't do the best on the V- and T-tests, and I'm surprised that the steady-staters not only kept pace with the other groups in all the performance indicators, but bested the other groups by a slight (statistically insignificant, but extant) margin across the board and by a truly significant margin on the T-test. 

Perhaps there's a limit to how fast one can get stronger and more powerful, and that two full-body training sessions per week just about does it for most people, so the addition of more body-weight style training sessions didn't ultimately contribute to improved performance.  

Finally, though--to keep with this week's theme of Don't Give Up on Old Ideas, the stud suggests that perhaps we've been too hard on that old standby, steady-state cardio.  Most people agree that it's boring and uninteresting, but seeing these study results, we've pretty much all got to admit that, as much as we're loathe to admit it, if you can stomach it, it's still effective.