Even if strength athletes don’t squeeze all the reps possible out of their sets they can still give their muscles the growth stimulus they need, and build up strength and muscle mass. Danish sports scientists at the National Research Center for the Working Environment came to this conclusion after doing a study in which 15 untrained women were the test subjects.
There’s no unanimous agreement among athletes, trainers and scientists about whether strength athletes need to train at failure: i.e. that they need to perform the maximum amount of reps they can in each set.
Those in favour say yes, of course: ‘intensity breeds immensity’. Those against say no, ‘failure breeds failure’.
The Danes got their subjects to perform lateral raises. On one occasion the women had to lift heavy weights with which they were only capable of performing three reps [3RM]. On another occasion the women used lighter weights, with which they could manage 12-15 reps. The women continued lifting these until they were no longer able to do so [Failure].
The researchers attached electrodes to the women’s muscles so they could measure how hard they had to work. The results are shown below.
The researchers discovered to start with that the women’s muscles worked harder at the lower weight, when they were able to perform 12-15 reps.
Secondly they discovered that when the women were using the lighter weights their muscles started to work more intensively the more reps they did, until about 3 reps before failure, when the intensity flattened off.
“Going to complete failure during lateral raise is not necessary to recruit the entire motor unit pool”, the researchers conclude. They emphasise that the subjects were untrained. Whether their findings are also valid for athletes who have been training for a number of years they don’t know.
Muscle activation strategies during strength training with heavy loading vs. repetitions to failure.
Going to failure, or not, has probably been one of the most debated issues during the history of strength training. However, few studies have directly compared the physiological effect of failure vs. nonfailure strength training. The purpose of this study was to evaluate muscle activation strategies with electromyography (EMG) during heavy repetitions vs. repetitions to failure with lighter resistance. Fifteen healthy untrained women performed a set with heavy loading (3 repetition maximum [RM]) and a set of repetitions to failure with lower resistance (?15 RM) during lateral raise with elastic tubing. Electromyographic amplitude and median power frequency of specific shoulder and neck muscles were analyzed, and the BORG CR10 scale was used to rate perceived loading immediately after each set of exercise. During the failure set, normalized EMG was significantly lower during the first repetition and significantly higher during the latter repetitions compared with the heavy 3-RM set (p < 0.05). Normalized EMG for the examined muscles increased throughout the set to failure in a curvilinear fashion--e.g., for the trapezius from 86 to 124% maximal voluntary contraction (p < 0.001)--and reached a plateau during the final 3-5 repetitions before failure. Median power frequency for all examined muscles decreased throughout the set to failure in a linear fashion, indicating progressively increasing fatigue. In conclusion, going to complete failure during lateral raise is not necessary to recruit the entire motor unit pool in untrained women--i.e., muscle activity reached a plateau 3-5 repetitions from failure with an elastic resistance of approximately 15 RM. Furthermore, strengthening exercises performed with elastic tubing seem to be an efficient resistance exercise and a feasible and practical alternative to traditional resistance equipment. PMID: 21986694 [PubMed - indexed for MEDLINE] Source: http://www.ncbi.nlm.nih.gov/pubmed/21986694