The question: Big weights, few repetitions. Smalls weights, lots of reps. CrossFit. HIT. I'm so confused. How much weight should I lift?
The answer: The legend of Milo of Croton, a six-time Olympic champion wrestler in the sixth century BC, whose training is said to have involved lifting a calf over his head every day until it became a full-grown cow, teaches us two lessons about weight training.
First, your workload needs to progress if you want to keep improving. Second, the precise details of what equipment you use and how you use it probably don't matter too much.
As a starting point, the American College of Sports Medicine recommends doing a range of exercises targeting different muscle groups, each with a weight that you're able to lift eight to 12 times. (You can find the appropriate weight through trial and error over the course of a few workouts and then adjust as you get stronger.) This will produce good results for three or four months – but to maximize your gains after that requires adjustments.
The traditional approach to building strength and muscle mass is to emphasize fewer repetitions, lift heavier weights and take longer rests. A typical workout may be three sets of four to six repetitions for each exercise, taking three minutes of rest between each set.
Building muscular endurance without bulking up, on the other hand, may call for four sets of 20 or more repetitions with less than 90 seconds between sets.
Then there are countless alternate approaches, such as the currently popular CrossFit regimen, which emphasizes short, high-intensity workouts, and the high-intensity training system pioneered by Nautilus inventor Arthur Jones. HIT, as it's known, often calls for a single set of each exercise, performed at a deliberately slow pace of 15 seconds or more for each lift.
Like cow-lifting, these programs undoubtedly produce significant gains. Whether they're better than traditional programs is another question.
A study published this year in the Journal of Strength and Conditioning Research found that slow lifting fell somewhere in the middle between strength and endurance training.
“You can gain [both] strength and muscle endurance,” said Sharon Rana, the Ohio University associate professor who led the study, “but the traditional methods are going to do a slightly better job for those two things.”
Similarly, a recent review in Advances in Physiotherapy concluded that single-set training was sufficient for staying fit, but that multiple sets were needed to gain the greatest possible strength.
One aspect that is sometimes neglected in the strength-endurance dichotomy is power – the ability to generate force rapidly, which is crucial in sports. That's a problem that exercise physiologist Greg Wells has encountered in his work with the Canadian national golf team. “Traditionally, these guys focus on getting stronger and building bulk,” he says, “but then they slow down and can't hit the ball as hard.”
Specific weight-training sessions to develop power incorporate light loads (similar to muscular endurance training) lifted at explosive velocities, as well as jumping and medicine ball exercises.
Unless you're focused on a very narrow goal – developing the biggest possible bicep or lifting the heaviest cow – Dr. Wells recommends variety: If you're doing three workouts a week, focus one on strength, another on endurance and the third on power.
Alex Hutchinson is a former member of Canada's long-distance running team and has a PhD in physics.