Strength Training to Failure
A common question we receive in clinic is how many repetitions should I perform of this strengthening exercise? Clearly, enough repetitions are needed under a given load to promote beneficial changes within the tissues for improvements in both healing and performance. Ranges of repetitions range from < 5, 8-12 reps, and >15 reps depending on the intended goals of the exercise and the patient/client's capability. Another repetition goal gaining popularity is performing the exercise until muscle fatigue/failure regardless of the number of repetitions. The biggest limitation of this training is sacrificing intensity (amount of weight) in order to perform a high number of repetitions. A study recently compared the effects of training until failure with higher intensity exercises.
Looney and colleagues had healthy volunteers squat with 50, 70, and 90% of their maximum squat strength (J Strength Conditioning Research. 2016). Athletes were assessed for muscle activation during these exercises to determine which level of resistance and repetitions produced the most beneficial environment for strength gains and muscle growth. The authors results were consistent with the previous literature indicating intensity (higher weights) is more effective than training to fatigue (higher repetitions) for muscle performance. Athletes and clients are encouraged to pick a repetition range consistent with their goals and to lift a weight which leads to fatigue (only 1-2 good reps left at end of the set) within that repetition range. '