[Robert Duncan achieved his bachelor of science in exercise science from Appalachian State University and masters in Kinesiology and Sports Studies from East Tennessee State University. He has participated in multiple internships with high schools, at the collegiate level, as well as in the private sector. Robert is currently a part of Athletic Lab’s coaching mentorship program]
Why exactly do people go to the gym and resistance train? Whether it is to improve performance in sport, change body composition, or to get “tone” you may not be training with the right intensity to optimally stimulate a hypertrophic response. Muscle hypertrophy is the technical term for muscle growth, and it refers to the increase in the size of your muscle cells. The most efficient way to produce a hypertrophic response is high-intensity resistance training, equal to or greater than 80% 1RM and eccentric contractions at 100 – 120% 1RM. It is at these intensities that integrated electromyographic activity has been shown to increase. This elevated neural activation contributes to an increased muscle tonus, an electrophysiological phenomenon, and to strength gains early on in the training period, with muscle hypertrophy contributing to further strength increases later in training. With the increase in the cross-sectional area of a muscle being directly correlated to the increase in maximum force production potential of the muscle. Muscle tonus refers to an increased ionic flow across the cell membrane and gives the muscle a firm appearance. Thus, if toned muscle are the goal, strength is the best method for achieving this appearance.
To begin, previous research has shown training with loads at or above 80% 1RM and eccentric contractions at or above 100 – 120% 1RM allow for 10 reps at the most. Thus, I would suggest using your 1RM to calculate higher rep maxes from the values below that are based on the Epley Equation. This new higher rep max can now be used to calculate relative intensities to use in your work sets. (ex. 5RM = 100 x 0.73 = 73 x 0.9 = 66 would be 90%)
Estimating higher rep maxes from 1RM
2RM = 1RM x 0.93 3RM = 1RM x 0.88 4RM = 1RM x 0.85
5RM = 1RM x 0.82 6RM = 1RM x 0.79 7RM = 1RM x 0.76
8RM = 1RM x 0.73 9RM = 1RM x 0.70 10RM = 1RM x 0.67
**Based on Epley Equation
Even though large muscle hypertrophy may not desired by every individual (e.g. distance runners, athletes in weight class sports), it would be unwise to completely exclude high-intensity resistance training from your training program. I would suggest keeping the volume of such high-intensity training low as to not elicit a large degree of muscle mass growth, while still obtaining the strength and power increases brought about by the high-intensity training. In addition, some of the training adaptations may be compromised by other components of the training program, such as aerobic conditioning, and the inclusion of high-intensity training maybe necessary to counter the catabolic effects of these other types of training within your training program.
While sport performance is important to only a small portion of the population, the value of high-intensity resistance training and the hypertrophic response it elicits should be desirable to everyone. Skeletal muscles primary task is locomotion, but they also regulate whole body metabolism. It is also well known that after the age of 30 years old the degradation of muscle mass increases. With the loss of muscle mass potentially leading to disability, loss of independence, and increased risk of mortality, the maintenance of muscle mass is recognized as a determinant which directly influences an individual’s quality of life. The inclusion of high-intensity resistance training has the potential to benefit everyone by countering the naturally occurring catabolic effects of aging.
In conclusion, high-intensity resistance training is the optimal intensity to elicit a hypertrophic response. Though large muscles are not desirable to everyone, the inclusion of resistance training at these intensities within your yearly plan will increase muscle tone, strength, and power. The key to limiting the absolute muscle size would be lower volume of resistance training (~ 9 – 15 reps per lift ). All things considered, high-intensity resistance training is the optimal strategy for optimizing hypertrophy, but also as therapy strategy for people with Parkinson’s disease, type 2 diabetes, and stroke survivors.
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