Mon 2 Jul 2012
Posted by Doug McGuff under Uncategorized
I did the following WOW’s since the last post. Once again, recovery has been quicker than in the past.
Pulldown on SS Systems
MedX Chest Press
Nautilus Pullover with SS retrofits
MedX Compound Row with SS fall-off cam
MedX Leg Press
MedX Overhead Press
Biceps Curl with EZ bar (split stance/MAE style)
Nautilus Plate-loaded Tricep with SS retrofits
Reverse grip (pronated) curl with EZ bar
Formulator wrist flexion
MedX Leg Press (reclined position with dead end-stop/squeeze technique)
Chris Highcock posted this article over at Conditioning Research. It asserts something that I have believed and found prior literature to support: the idea that full motor unit recruitment occurs before failure occurs. I suspect that full motor unit recruitment occurs at about 85% the way to failure and the rest of the way is increased firing rate and summation of these motor units. The million dollar question is whether simply recruiting is enough of a stimulus or if the summation and exhaustion is necessary. The article below obviously assumes that recruitment is enough.
Muscle Activation Strategies During Strength Training With Heavy Loading vs. Repetitions to Failure
Sundstrup, Emil1; Jakobsen, Markus D.1; Andersen, Christoffer H.1; Zebis, Mette K.1,2; Mortensen, Ole S.1,3; Andersen, Lars L.1
Abstract: Sundstrup, E, Jakobsen, MD, Andersen, CH, Zebis, MK, Mortensen, OS, and Andersen, LL. Muscle activation strategies during strength training with heavy loading vs. repetitions to failure. J Strength Cond Res 26(7): 1897–1903, 2012—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.
The article makes a couple of assumptions that I do not necessarily agree with. First, there is doubt in my mind whether EMG activity accurately reflects motor unit recruitment, as this is a controversial topic in the literature. The second assumption is that the decreasing power frequency as measured by the EMG was entirely due to fatigue of motor units as opposed to decreased effort on the part of the subject due to discomfort or due to the activity of inhibitory neural activity (Tim Noakes’ central governor theory). Finally, elastic tubing on a lateral raise exercise probably is the worst possible model for efficient muscular loading with an utterly backwards strength curve from the ideal situation.
Despite the limitations of the article, it does provide a couple of interesting talking points. First, the notion of subfailure training as being as productive as training to failure. I certainly experienced good results with stopping with failure as opposed to the deep inroad technique. Secondly, how the research can ask an important question but devise the worst possible methods for investigating the question. In this case they selected subjects that were least likely to “dig deep” and most likely to succumb most quickly to discomfort or the central governor. They selected the worst possible model for muscular loading: rubber tubing that provides almost no resistance at minimum moment arm and maximal resistance at maximal moment arm (completely backwards strength curve). Lastly, they assumed EMG readings accurately reflected fatigue, and that this fatigue accurately reflected motor unit recruitment.
So like most studies…it provokes interesting discussion, but its design and methods are so bad that no conclusions can really be reached.
Post your WOW’s and your thoughts.