Most people who work out frequently cite some “common knowledge”  whenever they are asked about the number of sets, reps, or minutes spent exercising that “gets the best results.” However, these maxims are probably more likely to be firmly entrenched in folk knowledge than actual science. Take as two relevant examples, a pair of articles recentlty published in the new york times —  both of which address women specifically, but could be easily generalized to men.

The first deals with the very common belief that if you want to “get toned” rather than “getting big” you should lift lighter weights with higher rep counts. Many of the fitness sources I have consulted in the past (including my current regimen — p90x) cite this as fact. Turns out this claim is not substantiated by science. In fact, lifting heavier weights in fewer reps is a bigger boon to losing weight and “getting toned.” This strategy also works for “getting big”  but requires the addition step of heavier calorie consumption.

The second article addresses a murkier topic with much more variability with regard to “rules of thumb.” It deals with the amount of exercise needed for women to  maintain a healthy body weight. I’m actually very surprised by this one. All that a normal body weight woman needs is one hour of moderate activity or half an hour of brisk activity to avoid gaining more than five pounds over any three year period. Heavier women appear to need more (though it is not clear how much they need).

As I have said before, I am a fan of empirical work that supports one method over another. Sure it’s not always cut and dry and it rarely gives us a certain answer. But I much prefer some scientific evidence to “a guy at my gym said” or “my grandpa used to say.” Anecdotal evidence is appealing because everyone wants to have the magic remedy (especially if no one else has it), but losing weight is no different than any other difficult goal. The surest path to success is the one paved with hard work and lined with sweat.