When we think about strength training most of us have the image of a heavily muscled person who is lifting weights until they can’t lift anymore.
They grimace, grunt, and gasp as they finally almost collapse on the floor from fatigue.
But is that the best way to do weight training?
The answer depends on what the objective is. And the method of doing weight training to the point of complete exhaustion, or muscle failure, can be misdirected and even counterproductive if you are unaware of some of the unintended consequences.
Strength training in this way requires one to perform a lift to the point of complete fatigue induced by previous muscular work. Although this state may be reached after only a few repetitions using high loads, moderate loads can also achieve this effect if done with enough repetitions, and are more commonly used when training to failure in practice. This approach has been used successfully to produce stronger and larger muscles in men and more dense (higher mass) muscles in females. And even though females will gain density with this very high intensity training, any gains in muscle size will be minimal because of the small amount of testosterone in women’s bodies.
Are there any populations that would not benefit or be adversely affected by this type of training? There are a few. As one might expect, people with medical conditions, the elderly population and sedentary beginners to exercise would be at risk with heavy lifting. And if one’s goals include general fitness and improved functioning around home and work, then it would be much better to undertake a moderate form of resistance training where you don’t lift until muscle failure.
But many athletes will not benefit from heavy lifting, or at least not as the predominant method of training.
Athletes do require a certain amount of strength, but not necessarily a high degree of muscle mass (also called hypertrophy), especially if the sport requires speed, agility and power.
The problem with training to complete exhaustion is that as the person lifts each repetition, nearer and nearer to failure, the speed of movement slows. In effect, in addition to generating hypertrophy, you are training your movements to be slow – and that is an anathema to speed sports.
Therefore, when power is the objective, exercises should be performed for sub-maximal repetitions of up to six reps with a load that is about thirty to seventy percent of a maximum load and done with fast, forceful movements.
Research has indicated that velocity and acute power output decline after approximately four to six repetitions per set. In order to maintain this kind of high power output, it would be most productive to rest the working muscles three to five minutes between sets.
However, rather than passively resting between sets, athletes may perform exercises for uninvolved muscle groups to improve time efficiency.
Athletes will often spend a portion of the year in the off-season trying to increase hypertrophy, but during the preseason and in-season training phases, development of power is often the primary focus, and maintaining high velocities and strict technique is of paramount importance during all training exercises.
In this case, the use of repetition failure sets would be counterproductive since reduction in velocity and technique deteriorization with increasing levels of fatigue, could increase the risk of injury.
Weight lifting to failure can be, and is, successfully used to improve strength and mass, but it is not the only way to strength train, and sometimes can be counterproductive.
As always, your destination or goal determines the method you use to get there.
• Kerry Senchyna holds a bachelor of science degree in kinesiology and is owner of West Coast Kinesiology in Maple Ridge (westcoastkinesiology.com).