Are you spending hours training but not seeing the results? Feel like you're doing heaps of exercises but spinning your wheels? The concept of "less is more" is contextual but applicable to exercise selection. What if I told you, you only had to do two exercises with a dumbbell to train your biceps completely?
What do you mean completely?
Well by manipulating the strength curve, we can challenge all muscle fibres in the biceps, or any other muscle, to save time but also maximise results.
This first blog post will outline the principle of the strength curve and training muscles at different lengths. Future blog posts will explore specific muscle groups so you can find out the best way to train each area.
So, what is the strength curve? It is the relationship of the muscle fibres within a joint and how much force they can produce at certain angles. We can split this curve up into three main components:
stretched position of the muscle
mid-range position
shortened position
Let's apply this to the hamstrings and glutes.
The stretched position of your hamstrings and glutes occurs at the bottom of a Romanian deadlift.
The mid-range position of your hamstrings and glutes can be seen at the beginning of a rack pull.
The shortened position can be seen at the top of a hip thrust.
We can see that all three exercises train the hamstrings and glutes but in three different ways depending on where the load is challenging the joint. For the best results, you will want to train all three positions to overload all muscle fibres rather than doing multiple exercises that challenge the same position. If you are able to systematically approach your training with this principle in mind, you will avoid spinning your wheels and burning yourself out.
This is only one half of the equation as different muscles have different resistance profiles, which we must complement with the strength curve of exercises.
Let's look at an ascending strength curve. There is a direct linear correlation between an increasing joint angle and the force produced. A great example of this is a bench press for the triceps where they can produce more force as they shorten as you press up.
However, in the same bench press, the chest muscles are strongest in the bottom where they are most stretched but lose force production as you press up. This means the pectorals will have a descending strength curve.
Being able to match exercises to the specific strength curve and resistance profiles of target muscle groups will further improve your efficiency with training. This is relevant not only for hypertrophy but for all types of training as we want to maximise muscle fibre recruitment and minimise injury.
This can be quite challenging to assess for each individual muscle and exercise. Furthermore, incorporating this into a rehab, gym or training program with other variables to factor in only adds to the complexity. However, working with a physiotherapist or coach who is aware of these basic S&C and biomechanic principles will allow you to effectively progress towards your goal.
If you have any questions about your training, remember we can:
measure your current strength and power using VALD ForceDeck
design a training / exercise program based on any deficits we identify through a physio and ForceDeck assessment
show you how to correctly do each exercise for the target muscle
regularly check in with you to see how you're going with your training
safely help you progress your training and/or rehab by updating your program
re-measure your strength and power gains using the VALD ForceDeck.
This blog was written by our physiotherapist Andrew Phan.
References
Kulig, Kornelia Ph.D.; Andrews, James G. M.S.; Hay, James G. Ph.D. Human Strength Curves, Exercise and Sport Sciences Reviews: January 1984 - Volume 12 - Issue 1 - p 417-466
Tillaar, Roland & Saeterbakken, Atle & Andersen, Vidar. (2022). The Acute Effects of Attaching Chains to the Barbell on Kinematics and Muscle Activation in Bench Press in Resistance-Trained Men. Journal of Functional Morphology and Kinesiology. 10.3390/jfmk7020039.
Wallace, Brian & Bergstrom, Haley & Butterfield, Timothy. (2018). Muscular Bases and Mechanisms of Variable Resistance Training Efficacy. International Journal of Sports Science & Coaching. 13. 1177-1188. 10.1177/1747954118810240.