Actually, before we go into the science behind of the number of sets, I'm gonna need you to try and reassess your thought processes regarding sets as a whole. When a number of sets is recommended, it's generally done similar to when a doctor prescribes a dosage of medication. Doctor’s frequently prescribe very small dosages of a drug, then increase the dosage until the body responds to the active ingredient in the drug. If a dosage is too high, the body will plateau and side effects may result. So, just like the dosage of a medication, your body’s response to strength training (increase in strength and muscle mass) will increase depending on the number of sets of each resistance exercise. However, with too many sets, this response will plateau and too many sets can have side effects, possibly even injury.
Moving on, here is what the science states according to a recent entry in the Journal of Strength and Conditioning. With one set of resistance training to muscular failure or near failure, minimal strength gain does occur thereby making multiple sets superior. By performing two and three sets of the same exercise, a gain of 46% can be expected over completing just one set. Four to six sets of the same exercise only yield another 13% gain over two to three sets. Strength training causes protein synthesis to occur in the muscular system. The more sets we perform, the more protein synthesis that occurs until our body reaches a plateau, which could be somewhere around five or six sets.
So how many sets are you going to perform for your next workout? Here’s my suggestion. If you're only interested in general fitness or if you lack the time for a resistance training program and do not need maximal strength gains, then one set to near failure of resistance training should be sufficient. If you are interested in maximal strength gains, then multiple sets per exercise are necessary with three sets being a great starting point. Depending on your tolerance of resistance training two sets can help prevent muscle soreness for someone just starting their strength-training program. Four to six sets and you may reach the land of no return. The gains may not be worth the time and effort, unless of course you are a bodybuilder, consuming tubs of protein, creatine, insulin and other legal and illegal aids. Next up: stay tuned for some knowledge on repetitions.