Strength continuum: One of the key concepts of S&C
The strength continuum is a concept to classify the exercise based on the Force/Velocity curve.
The F/V curve is the relationship between force and velocity as displayed below in the graph. An increase in force will enhance a decrease in velocity, and vice versa.
If we link the first post on strength training
we can define that exercises performed at slower velocity e.g Maximal strength exercises (compound movements, powerlifting etc..) allow to form more cross bridges = and develop more force.
On the other hand, exercises performed at high velocities will produce less force.
Ultimately, the goal in the majority of sports (Depending on the type of movement) will be to shift the curve to the right and allow the athlete to produce more power, let’s break it down now every part of the F/V curve.
1#Maximal strength
Maximal strength represents the maximal force production. Here we can have isometric contractions, where the muscle generates force without changing length. In isometric contractions, the muscle can produce its maximal force output because it's not impeded by the speed of contraction.
It also refers to the maximum amount of force a muscle or group of muscles can generate in a single maximal effort. It's typically measured by how much weight one can lift for a single repetition in exercises like squats, deadlifts, or bench presses. We can define maximal strength between 90-100% of 1RM.
As we’ve seen in the first post, through motor unit recruitment, rate coding, synchronisation, and central nervous system adaptations, the nervous system coordinates muscle activity to generate the highest possible levels of force.
The force-velocity curve for maximal strength provides important insights into the relationship between force production and movement velocity, which is crucial for understanding muscle performance during resistance training exercises.
In a practical context, the number of repetitions will be low (1-5) and recovery among sets will be high > 3’ as you will need to give to your body and nervous system to recover before the other sets.
2#Strength-speed
It refers to the ability to rapidly generate force against a resistance in a short period of time. It involves the capacity to exert high levels of force at moderate to high velocities and on the F/V curve it will be between 80-90% of 1RM.
The strength-speed is fundamental for sports that require explosive power and quick force production, such as sprinting, jumping, throwing, and various athletic movements.
A perfect example of strength-speed will be Olympic lifts and their variation performed above 80% of 1RM.
It also enhances the development of fast-twitch muscle fibres, which are primarily responsible for generating explosive force.
3#Power
Moving down to the curve we find the power = F x V.
The force-velocity curve demonstrates that power output is highest at intermediate velocities. In this zone, the muscle generates a balance between force and velocity, resulting in maximal power production. This optimal zone goes between 30% to 80% of an individual's one-repetition maximum (1RM) for a given exercise.
A good example of those can be all the variations of Olympic lifts such as high pull from the floor, hang power clean, throw, bench press and so on.
Rest among sets will be 2-3’, the barbell should be moved intentionally fast, and sets will be 3-4 x 3-5 repetitions.
4#Speed-strength
The optimal zone on the speed-strength curve typically falls at velocities between 30 and 60% of 1RM.
Therefore, the muscle can produce high velocities of movement while still exerting considerable force. Exercises in the speed-strength range enhance rapid force production and explosive movements.
Exercises example for speed-strength will refer to plyometrics movements as well as hurdles, jumps and loaded jumps.
Rest among exercises will be 1-2’, sets will be around 3 and repetitions up to 6.
5#Speed
Coming at the end of the curve we can find speed or velocity.
It refers to the maximum velocity for a given movement that an individual is able to produce.
The % of 1RM in this case will be up to 30% and exercises will fall under the category of sprinting, hopping and fast plyometrics.
We should have clear in mind that speed can be trained if there is a good amount/quality of work of the previous components of the F/V curve.
#Conclusion
Every sport is different and requires a variety of movements, so understanding the value of the F/V curve is essential for an S&C coach.
Assessing and testing the athlete is fundamental to establishing what type of zone of F/V curve will need to train in order to shift the curve to the right and therefore produce more power. This is the reason why “Individualization” is key to improving performance, as individuals have different training needs even if they practice the same sport.
The strength continuum provides a structure for progressing individuals through different phases of training as they develop their strength capacities.
Working on all zones of the F/V curve allows individuals to develop a variety of athleticism qualities, in fact, every point on the strength continuum contributes to overall athletic performance in different ways. Maximal strength is essential for overcoming resistance and generating force, power is crucial for explosive movements, and speed-strength enhances quickness and agility. By developing all aspects of strength along the continuum, athletes can optimise their performance potential.
And you? Have you ever considered all of these aspects of physical preparation? Let me know in the comments or feel free to message me.
See you next week!
Vitality Vortex