As the title suggests, a big component of Strength and Conditioning is strength training. As a physical quality, strength plays a huge part in athletic performance. Strength underpins power (as discussed in last weeks article) and well strength. For many sports, the ability to produce power in a very short period of time is important. Ranging from cricket where the bowler needs to move the ball as fast as possible, to golf where there needs to be large amount of power in the club swing to increase the distance the ball travels. Looking into contact sports, you wanna be able to produce as much power if you are running into contact, or if you are the defender, you want to be able to apply as much force into the tackle to try and reduce the attackers momentum. Looking at strength, a scrum in Rugby union requires huge amount of strength and force production, with combined pack weights in professional Rugby Union exceeding 1.5 tonnes.
Strength is also hugely important for endurance sports. Stronger athletes are able to produce more power than weaker athlete’s, meaning their potential for locomotion, regardless of mode (Cycling, running, swimming etc), is greater. They will also have a better economy and will require less energy / effort for locomotion, meaning they can go harder for longer thus improving performance. Better economy is also aided by better posture / position, which is improved by strength training. Athlete’s can sustain a more economical position (E.g for runners this would be upright, not hunched over) for longer before fatigue sets
Finally, strength training is hugely important for injury prevention. Athlete’s who are stronger, are at less risk of sustaining an injury during play / competition. Adaptations elicited by strength training, cause an increase in strength in skeletal muscle, ligaments and tendons. Improving strength of the tissue around joints, helps to stabilise the joints thus making them more robust. For joints such as the shoulder, this is a huge benefit as it is one of the most “at risk” within the body. The increased strength in musculature and connective tissue also helps to dissipate / absorb and reapply forces safely during manoeuvres like sidestep cutting where there are large multiplanar forces in action.
If you have read this, or spent any time reading my posts or articles you’ll have seen me banging on about the importance of strength training for all populations. Athletic, gen pop, youth, masters & even OAPs can all benefit from strength training, but some of you may be wondering what strength training actually is. Yes, it is training to improve strength, but how do these adaptations occur? How strong do you need to be? Is there a downside to being strong? Lets have a look.
Is there a downside to being strong?
No, simply put there isn’t. People often get confused between physical size (I.e bulk) and strength. You do not need to be big, to be strong. Having more lean muscle mass can increase your strength potential (Discussed later) but it is not a necessity. There are some people who are pretty light, and seriously f*cking strong. Lightweight male and female weightlifters / powerlifters are prime examples of this. Regardless of the fact they are strength athletes. the point remains. But even looking at athlete’s outside of strength sports, some pretty lean and reasonably small framed athletes are throwing around some serious tin
What causes improvement in strength?
Improvements in strength can be from a combination of neural and structural / muscular architectural adaptations. Firstly we will look at neural as these adaptations occur first
Neural adaptations to strength training
Firstly, a brief overview on how a muscle contracts, it might appear a little heavy reading, but stick with it…
When a muscle contracts, a physiological mechanism known as the sliding filament theory occurs. For a muscle to contract in the first place, there needs to be an electrical signal which is referred to as an action potential (AP). This signal is sent from the Axon, to the neuromuscular junction (NMJ), which is found within a motor unit. A motor unit is comprised of several motor neurons, and the muscle fibres which they innervate. When the AP reaches the NMJ it causes a diffusion of Acetylcholine (Ach) across the NMJ. This causes a chemical reaction which releases calcium (Ca2+) to be released from from the endoplasmic reticulum (ER) , allowing muscle contraction through cross bridge formation, also known as the sliding filament theory.
The sliding filament theory is the physiological interaction between Actin and Myosin Myofilaments. Actin Myofilaments are made up of Actin molecules, and a Troponin / Tropomyosin complex which combined, form a helix structure. Myosin Myofilaments are composed of Myosin light chain, and Myosin Heavy chain molecules. Within the Myosin myofilaments, there are Myosin heads, which are responsible for binding to the Actin Molecule. However, The Troponin Molecule covers the Myosin binding site on the Actin Myofilament and must be removed for cross-bridge formation to occur. Myosin binding sites are uncovered when Ca2+ is released from the sarcoplasmic reticulum and binds to the Troponin molecules, allowing the Myosin head to attach to the binding site, allowing the formation of a cross-bridge.
This cross-bridge formation happens multiple times when a muscle contracts, irrespective of the task at hand. As I am typing this, 100’s of cross bridges are forming in my muscles, allowing me to type. When we exercise, the same thing happens on a greater scale, which is where motor units come in. Motor units follow what is referred to as Hennemans size principle. For day to day, low energy / effort tasks (Such as typing) small motor units are recruited. The more intense the task, the more motor units are recruited, following a small to large pattern (Hence the name size principle). In high force movements (E.g a 1rm squat) cross briges will continue to form until the muscle has gone through a full contraction (I.e completes the lift) or until failure. Failure will occur either from insufficient energy (Substrate depletion – more likely in a rep out set) or the indicidual is unable to produce enough force to overcome inertia. The inability to produce sufficient force to overcome inertia, could be from one of two things. Firstly, you may just not be strong enough to lift the damn weight in the first place. Secondly, fatigue may have set in which has hampered your ability to apply sufficient force, this could be from substrate depletion (previously mentioned) or metabolite accumulation.
I appreciate that the above is heavy on the physiology aspect, but it is important to understand it, otherwise you wouldn’t have a bloody clue what I will be talking about now. You may be wondering what that actually has to do with strength training?
When you participate in strength training, you increase neural drive. Consequentially, this improves your ability to recruit higher threshold motor units, which allows more force production. This also increases the number of cross bridges which can be created, again increasing the amount of total force which can be produced. Finally, it can improve a something known as “rate coding”. This is simply the rate at which motor units are recruited, and AP’s are discharged. Neural adaptations to strength training can occur in a number of sessions. Beginners to the gym experience huge neural adaptations, often referred to as beginner / noob gains where there appears to be a huge increase in strength. Strength training also increases motor unit synchronicity, where the body becomes more adapted to motor unit recruitment patterns in a specific way. This is another reason why it is best to stick with specific exercises for a reasonable length of time (Ideally until you just don’t get much more out of them) to build this synchronicity. Like most things, repetition is key
Structural / architectural adaptations
There are also adaptations which occur from a muscle structural / architectural standpoint from strength training. The majority of skeletal muscles are a specific type of musculature known as pennate muscles, referring to the pennate fibres in the muscle. These fibres are at an angle to the longitudinal axis to the muscle, and this angle is referred to as pennation angle. Through resistance training, the angle of pennation increases, which has been shown to increase force production.
Secondly, there are links between resistance training and muscle hypertrophy (Muscle size) I know, shocking right?. Hypertrophy can be a double-edged sword, and I will be discussing why in a later article. But as a general rule of thumb, a muscle with a larger cross-sectional area (CSA) has the potential to produce more force.
Initially, it was thought that muscular hypertrophy only really occurred in a certain range (60-75% of 1rm), and that working below this range improved muscular endurance, and working above this range worked on strength. There is some truth to this, however research has shown that muscular hypertrophy can be elicited in ranges as low as 30% 1rm, and as high as 85% of 1rm. This has changed our understanding of muscular hypertrophy & has had some implications for S&C when it comes to programme design. As I said, I will discuss hypertrophy, its mechanisms and implications of muscle growth for athlete’s in a later article, but when it comes to improving strength, increased muscle mass can help improve your strength. Prime examples of this lie within strength sports, where on average, as the weight class increases, both individual lifts and totals (Competition total of sum of weight lifted across competition lifts) increase.
How to improve strength
To improve strength, you need to be engaging in a from of resistance training. This can be barbell / dumbbell training and also bodyweight / calisthenic work. However, the latter will have a point of diminishing returns once you have mastered your bodyweight due to the progressive overload principle ( as written about here – https://www.stewartathleticdevelopment.com/post/what-drives-progression-the-key-to-understanding-and-implementing-progressive-overload). It is far easier to overload barbells / dumbbells than it is to overload your body, certainly whilst maintaining athleticism and a high power / weight ratio. When carrying out training, you want to be working at higher ends of the intensity scale (70-85% 1rm) for your working sets. Strength can be improved at higher intensities, but there becomes a skill element with maximal (Or very close to) loads, and carry a higher risk if things go long. Failing lifts can also have a very fatiguing effect, and you also don’t wanna risk failing from a safety perspective. As always, progressive overload is key, and deload (If you are unsure how to deload – check here https://www.stewartathleticdevelopment.com/post/a-beginners-guide-to-deloading-how-to-take-your-foot-off-the-gas-without-ruining-progression). Consistency and patience is key with strength (and all types of training), the gains will come over time!
Until next time, and as always
Stay safe, stay strong
Callum
