What are resistance profiles & why are they important to understand for resistance training & hypertrophy emphasis?

Resistance profiles are considered the difficulty of an exercise & how it changes throughout its range of motion. This is due to the mechanical properties of the movement, load distribution, & the equipment being utilized for the exercise. Gaining a better understanding of resistance profiles can be a game changer due to the fact that your training can be optimized, helping the difficulty of the exercise match the muscle’s strength curve. 

What are the different types of resistance profiles? 

1. Ascending Resistance Profile - The exercise becomes more challenging as you move through the range of motion. These make movements like squats deadlifts, & bench press more difficult due to the fact that at the top of the moment, mechanical leverage improves as you extend. 

1. Descending Resistance Profile - The exercise becomes hardest at the beginning & begins to get easier as the rep is completing. Movements like barbell rows & pull-ups are great examples of this. The muscles activated are at a mechanical disadvantage at the start, but gain leverage as the movement begins to progress throughout the concentric contraction. 

1. Bell-Shaped Resistance Profile - The exercise becomes hardest in the middle of the range of motion or middle of the concentric contraction. Bicep curls & lateral raises are examples of movements that experience the peak of resistance when the lever arm or moment arm is longest, which is usually targeted around the midpoint of the movement. 

Being able to understand resistance profiles is highly crucial for hypertrophy/muscle growth. Understanding these profiles helps you maximize muscular tension, fatigue, & mechanical tension. Knowledge of resistance profiles can help with better muscle stimulation, improved target muscle activation, decreased risk of injury, & more, leading to program optimization. Let’s take a deeper dive into this. 

Better activation: Being able to match the exercise’s resistance profile with a muscle’s strength curve ensures that the muscle experiences constant tension throughout the movement. This will increase fiber recruitment, limit the use of momentum & secondary musculature recruitment, & increase mechanical tension.

ROM: Different joint angles cause muscles to be more active. Being able to balance resistance profiles can ensure that muscles are effectively trained through their entire possible range. This helps veer away from overload in just one portion of the movement. This is why it is important to ensure that muscle groups experience movements that embody different resistance profiles, such as a barbell flat bench (ascending profile) being paired with a cable chest fly (bell-shaped profile).

Poor profile alignment: If you are engaging in exercises with poor resistance profile alignment, you will 100& overload the joints in weak positions. You can see how this can be considered dangerous. Prevent overuse injuries & boost joint/connective tissue/musculature longevity. 

Being able to optimize fatigue + recovery: You shouldn’t be only challenging muscle groups in their strongest positions. Vary resistance profiles can maximize tension without excessive fatigue, balance intra-set recovery, & help you avoid plateaus by targeting muscles with variation. 

Peer reviewed articles to support this info:

Regional hypertrophy: the role of exercise resistance profile in trained women

https://www.researchgate.net/publication/361527239_Regional_hypertrophy_the_role_of_exercise_resistance_profile_in_trained_women

Muscle Hypertrophy Response to Range of Motion in Strength Training: A Novel Approach to Understanding the Findings

https://www.researchgate.net/publication/362864671_Muscle_Hypertrophy_Response_to_Range_of_Motion_in_Strength_Training_A_Novel_Approach_to_Understanding_the_Findings

Evidence-Based Resistance Training Recommendations

https://www.researchgate.net/publication/228830087_Evidence-Based_Resistance_Training_Recommendations

Current Guidelines for the Implementation of Flywheel Resistance Training Technology in Sports: A Consensus Statement

https://link.springer.com/article/10.1007/s40279-023-01979-x

Effects of variable resistance training versus conventional resistance training on muscle hypertrophy: a systematic review

https://link.springer.com/article/10.1007/s11332-023-01103-6

Resistance training prescription for muscle strength and hypertrophy in healthy adults: a systematic review and Bayesian network meta-analysis https://bjsm.bmj.com/content/57/18/1211

Resistance Training Variables for Optimization of Muscle Hypertrophy: An Umbrella Review

https://pmc.ncbi.nlm.nih.gov/articles/PMC9302196/

Resistance Profiles & Strength Curves

https://www.elitefts.com/coaching-logs/resistance-profiles-and-strength-curves/?srsltid=AfmBOorl3Kon0c4gGr2MbA5mjLUGTd5L2fEPTCVXDTkAbXg_Z4IkxZiB

A Comparison of Strength and Resistance Curves for the Internal and External Rotators of the Shoulder in a Neutral Position chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://dc.etsu.edu/cgi/viewcontent.cgi?article=1837&context=etd

Comparing the effects of variable and traditional resistance training on maximal strength and muscle power in healthy adults: A systematic review and meta-analysis

https://www.sciencedirect.com/science/article/pii/S1440244022002201

Muscular bases and mechanisms of variable resistance training efficacy

https://journals.sagepub.com/doi/10.1177/1747954118810240

Does Varying Resistance Exercises Promote Superior Muscle Hypertrophy and Strength Gains? A Systematic Review

https://www.researchgate.net/publication/358212528_Does_Varying_Resistance_Exercises_Promote_Superior_Muscle_Hypertrophy_and_Strength_Gains_A_Systematic_Review