Written by Stefan Ianev (Clean Health Research & Development Specialist)
What is relative strength?
Relative strength refers to the ability to produce maximal force relative to your bodyweight. This differs from absolute strength which is the ability to produce maximum force irrespective of body weight.
As an example, suppose you had two individuals as follows:
Individual A
Body Weight – 100kg
Max Squat – 180kg
Individual B
Body Weight – 80kg
Max Squat – 160kg
In terms of absolute strength, individual A is stronger than individual B on the squat because they can lift more weight, i.e. 180kg vs 160kg.
However, in terms of relative strength, individual B is stronger because they can squat twice their bodyweight whereas individual A can only squat 1.8 times their bodyweight.
Relative strength vs absolute strength, what’s better?
In most sports, relative strength is more desirable that absolute strength, not only for athletes who are bound to competing in a weight class, but also for athletes that need to displace their own bodyweight. That includes all sports with running and jumping.
Consider this for a moment, if two athletes both had equal power in their legs, the lighter athlete would be able to displace their body further when running and jumping because they need to overcome less resistance. The heavier athlete would need to produce more force to displace their body weight the same distance as the lighter athlete.
In addition, the heavier athlete would need to absorb greater landing forces, which would put more stress on their joints. Even from a drop height of 60 cm as an example, ground reaction forces of 2.38 to 4.91 times body weight have been reported (1).
Also, excess muscle hypertrophy changes the pennation angle of the muscle fibers which reduces the velocity of contraction. Therefore, excess hypertrophy can slow athletes down, irrespective of the extra weight they need to displace. If you notice sprinters today are a lot leaner and less muscular than sprinters from a couple of decades ago.
So how does an athlete go about attaining relative strength? How does training for relative strength differ from training for absolute strength?
The primary difference is in the intensity and volume. When training for absolute strength you can train across a broader range of intensities and repetition ranges. Typically, when training for absolute strength you would use between 80-100% of your 1RM for 1 to 8 reps per set. This will allow you to maximize strength by increasing hypertrophy and improving neurological efficiency.
When training for relative strength, you would use between 85-100% of you 1RM for 1 to 5 reps per set. This will allow you to improve neurological efficiency and as well as improving structural adaptations such as increased tendon stiffness, while limiting muscle hypertrophy.
By improved neurological efficiency we mean:
- Increased motor unit recruitment
- Increased motor unit synchronization
- Increased motor unit firing frequency (rate coding)
In terms of muscle hypertrophy, a higher volume of work in terms of the total number of reps approaching failure may be required in order to expose the muscles to mechanical loading for a sufficient duration. Studies have shown that hypertrophy is similar for sets of anywhere from 6 to 25 reps on a per set basis (2). However, it appears that for sets of 5 reps or less, more total sets need to be performed to achieve the same hypertrophic effect (2,3).
This suggest that for increasing relative strength, athletes should perform fewer than 5 reps per set, limit the total sets per muscle group to 5 sets or less, and avoid training to failure. This will help ensure that athletes obtain the desired neurological adaptations and structural adaptations of the tendons, without accumulating too much volume to increase hypertrophy.
Equally, if not more important, athletes training for relative strength should maintain their caloric intake slightly below maintenance to avoid putting on bodyweight, because even at a lower volume, there is going to be some hypertrophy taking place when training with near maximal loads.
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References
- Niu W, Feng T, Jiang C, Zhang M. Peak vertical ground reaction force during two-leg landing: a systematic review and mathematical modeling [published correction appears in Biomed Res Int. 2015;2015:941923]. Biomed Res Int. 2014;2014:126860. doi:10.1155/2014/126860
- Schoenfeld BJ, Grgic J, Ogborn D, Krieger JW. Strength and Hypertrophy Adaptations Between Low- vs. High-Load Resistance Training: A Systematic Review and Meta-analysis. J Strength Cond Res. 2017 Dec;31(12):3508-3523. doi: 10.1519/JSC.0000000000002200. PMID: 28834797.
- Schoenfeld BJ, Ratamess NA, Peterson MD, Contreras B, Sonmez GT, Alvar BA. Effects of different volume-equated resistance training loading strategies on muscular adaptations in well-trained men. J Strength Cond Res. 2014 Oct;28(10):2909-18. doi: 10.1519/JSC.0000000000000480. PMID: 24714538.
