The Goals of Training
What is strength and how do we train it?
WHAT IS STRENGTH?
There are several definitions for the term "Strength", all of which are very context dependent. During your placement at Rise, we will define strength as "an athlete's ability to produce peak force". Whilst this definition seems relatively intuitive, there are several key physiological complexities to further examine.
Firstly, it's important to discuss the spectrum of simple to complex strength movements, and how at either end of the spectrum a slightly different set of physiological determinants will influence an athlete's strength with these movements. For example, consider a "simple" strength exercise, such as a seated machine knee extension. In this movement, the athlete is locked in place with no stabilisation requirements, and with the quadriceps being the only relevant muscle group for the performance of this exercise. In this case, only two key determinants will influence the athlete's strength: the ability of the athlete's nervous system to recruit the quadriceps, and the ability of the quadriceps to produce force. This is true for all simple/isolated strength exercises, with the obvious practical application being that simple/isolated strength exercises will only train these two factors. Considering instead a "complex" strength exercise like a barbell lunge, the same two determinants from the knee extension are relevant (nervous system input to a muscle, and muscle force abilities), however these two determinants will be true for ALL of the prime movers of a barbell lunge (i.e. bilateral quads, front leg glute, back leg hip flexor, possibly even bilateral calves too!). Additionally, due to the "complex" nature of this exercise, the athlete now has to coordinate all of these muscles to produce peak force in synchronisation with each other. Compared to the leg extension, this "complex" movement requires not only isolated strength abilities, but also a relatively challenging coordination ability too! Hence simple/isolated strength movements will typically be determined by nervous system input to a muscle and muscle force capacities, whereas complex movements will typically be determined by a combination of these factors as well as coordinative abilities. This is the reason why you can very quickly "train" an athlete to be super strong with isolated movement patterns like a leg extension, however getting an athlete to squat/lunge/deadlift etc heavy takes time for them to learn the appropriate coordination strategies to do so. Additionally, this is one of the reasons as to why we prefer to train "movements not muscles", as by overloading movement patterns with relevant coordinative strategies to an athletes sport, we are likely to see greater transfer to that sport.
WHAT PHYSIOLOGICAL QUALITIES INFLUENCE MAXIMUM STRENGTH?
The video linked below will discuss this in significantly more detail, and with visuals to help guide learning, however as was discussed above their are two key groups of factors that influence strength: nervous system factors, and muscular-specific factors.
Briefly, the nervous system is responsible for coordinating the patterns of muscular activation. Our central nervous system is responsible for intramuscular coordination (i.e. how many fibres and what fibres are recruited within a specific muscle), and intermuscular coordination (i.e. what muscle groups are recruited together, what muscle groups are inhibited). Intramuscular coordination is influenced by coordinative abilities such as how smoothly or effectively a muscle can be recruited, but also by neuro-physiological qualities like rate-coding, which influence the number of fibres recruited. Intermuscular coordination can generally be thought of as a coordinative skill only.
From a muscular point of view, there are two key factors influencing strength output: muscle cross sectional area and muscle architectural characteristics. Generally speaking, a bigger muscle is a stronger muscle, however it is important to consider the physiological cross sectional area of a muscle rather than anatomical cross sectional area. If you're unsure of the difference between the two, then refer to the video below. Other architectural characteristics such as pennation angle and muscle fascicle length (which are inter-related) will also influence strength output. Each of these muscle-specific factors are trainable, however they may require more specific methods of training, which will be discussed in a later Module (Week 8- Specific Focus: Training Strength).
HOW IS STRENGTH DEVELOPED?
Sticking with general principles for this section (more complex principles coming in week 8), there are several key training requirements to develop maximum strength.
#1: Resistance must be high
To train peak force output, peak force output must be produced consistently. Hence heavy weights/high resistance must be used such that athletes are required to produce peak forces. To facilitate high intensities, low reps must be used (generally <5 reps). As an aside, avoid the "new coach trap" of thinking low reps = strength gains, this is not the case. The reality is high resistance = strength gains, and high resistance can only be achieved through low reps, hence it's not the low reps that is the stimulus but the high resistance! Training with less than 80-90% of your 1RM will have very minimal effects on strength, except in the case of beginners who are still developing movement coordination and will experience "beginner gains".
#2: Rest periods must be sufficiently long
"You can't be strong if you're tired". If athletes are getting insufficient rest, then they are unlikely to produce peak force, and therefore won't be stimulated maximally.
#3: Intent must be maximal
"Intent" refers to the athletes intent to overcome the resistance. If completing 5 reps at 100% of an athletes 5RM, it is possible for the athlete to submaximally lift the first 4 reps (i.e. not lifting at 100% speed/intent), however the 5th rep by definition must be lifted with maximal intent (as that's the point of failure!). In this case, it's likely that the 5th rep will have the greatest stimulus for peak force, whereas the first 4 reps will be less effective due to slightly submaximal intent/force production. Hence even if training strength, it is still super critical that an athlete is cued to lift the weight as quick as possible (provided it's safe to do so and the athlete has basic competency of the movement).
#4: Strength is specific
As has been described in detail, there is significant coordination demands associated with strength, particularly with more complex whole body movements. Hence the type of strength you are looking to develop (i.e. isolated vs complex strength) will dictate what sort of movement patterns should be utilised for strength training.
INSERT VIDEO TALKING THROUGH FLOW CHART/HIERARCHY CHART OF PHYSIOLOGICAL QUALITIES UNDERPINNING STRENGTH. CNS THINGS (RATE CODING, ...?), MUSCLE ARCHITECTURE, MUSCLE CROSS SECTIONAL AREA, INTRA MUSCULAR COORDINATION, INTER MUSCULAR COORDINATION