What is Strength & Conditioning Training About?


The general goal of strength & conditioning (S&C) training is to improve the physical attributes that affect successful performance in an athlete’s sport. While the technical and tactical skills are developed through long hours of specific practice in the athlete’s main sport, the physical attributes are built and improved upon through other training means in order to allow for more effective application of sport skills by the athlete. Using a simple analogy, strength and conditioning training aims towards building a more powerful engine for a skilled race driver to race with. 

It's the same driver in both pictures, but do you notice the difference?
In order for S&C training to be effective, it needs to produce specific measurable results that will positively affect sport performance, and it needs to implement the most efficient training methods to do so. Things here are pretty cut and dry. S&C training needs to:
  • increase max strength
  • increase explosive power prodution
  • increase the power capacity of the aerobic and anaerobic energy systems
  • address any deficits in the movement mechanics of the athlete
  • manage/help rehabilitate injuries
  • achieve the above in a safe, measurable and time-efficient fashion while taking into account the specific physiological demands of the sport (and, when it comes to team sports, the position) and personal attributes (strong/weak areas, training history, injury history, psychological makeup, developmental age, etc.) of the athlete

For effective S&C program planning and implementation, coaches need to be fully aware of these goals and have the necessary knowledge base to tackle them properly. The athlete should also be aware of the basic facts surrounding the fundamental S&C training goals in order to be able to assess whether the services an S&C training center or professional is offering are of the proper quality that can produce the desirable results in the athlete’s sport performance.

...now let’s take a closer look at each of those specific targets of S&C training:

Max Strength
Max strength is the maximum amount of force the athlete can produce in a specific movement
, regardless of time constrictions. For example, max strength in the squat is the highest amount of weight an athlete can successfully squat in the full range of motion for a single repetition. In sports where the athletes need to move their body through space (e.g. sports involving sprinting, jumping and changes of direction) and in sports with weight divisions (sports like martial arts and weightlifting), the specific variable that matters is max strength relative to the athlete’s bodyweight, otherwise referred to as “relative strength”. For example, the relative strength of an 80 kg athlete with a 120 kg squat is 1.5 times his bodyweight (1.5xBW). If that athlete were to improve to a 140 kg squat while gaining 5 kg of bodyweight, his relative strength would improve to 1.65xBW, which is advantageous. If, on the other hand, he were to improve to a 140 kg squat while gaining 15 kg of bodyweight, his relative strength would decline to 1.47xBW and that would be disadvantageous. It should be noted that, regardless of gains in relative strength, bodyweight gains should also be weighed against any possible impact the added body mass may have on the athlete’s endurance.

Heavy strength training can transfer towards increased power production and a higher vertical jump.
It needs to be noted that max strength production is independent of time (in the max squat example, it doesn’t matter how many seconds the lift is completed in) and for that reason max strength is not directly applicable to most sports, since in most sport situations force needs to be produced and applied within very short timeframes. From the moment muscle contraction is initiated it generally takes over 300-400 milliseconds for max force to be produced. In most sports movements, like accelerations, changes of direction, jumps, throws and martial arts movements (strikes and take-downs), only a fraction of that time (typically between 100-300 milliseconds) is available for force production and therefore only the force produced in that limited timeframe is what directly influences performance. Exceptions, where max strength is indeed directly relevant, are sports that include instances where strength is developed in longer timeframes, with examples like the iron cross in gymnastics, resisting a hold in grappling and the first strokes of a race in rowing.

Despite the fact that it doesn’t directly influence performance, max strength is an important training variable in athletic development. Through properly designed training, greater max strength will translate to greater explosive strength (greater force applied in the short timeframes that matter), because the greater the difference between explosive strength and max strength the easier it is to increase explosive strength. This difference between explosive and max strength is called the “explosive strength deficit” and it shows the percentage of max strength potential not used during the specific explosive action. When the explosive strength deficit is large, the athlete is “stronger than he is fast” and the most effective option would be to put a greater focus in explosive power development, whereas when the explosive strength deficit is small, the athlete is “faster than he is strong” and the better option would be to place a greater emphasis on max strength development. Max strength is mainly trained in a general way, using basic compound exercises that can be easily and safely loaded in an incremental fashion (squats, deadlifts and presses being the main core of basic strength training) and using heavy weights for low numbers of repetitions.

To return to the race car analogy, max strength is the size of the engine and, while a larger engine doesn’t automatically ensure greater horsepower, a larger engine will allow for greater power production if properly designed and applied.

Explosive Strength/Power

Power is the rate at which work is produced and is defined as the amount of work performed divided by the amount of time it took (P = dW / dt, where P = power, W = work and t = time). In explosive sports movements, power production depends on the amount of force the athlete can produce in the short timeframe for force application, commonly referred to as “explosive strength”, and it directly influences how quickly/explosively the movement is performed. For example, in the vertical jump, the greater the force the athlete can produce within the ~200-300 milliseconds of force application, the greater the power production and thus the higher the jump is going to be. Explosive strength is the “holy grail” of athletic preparation for dynamic sports as it directly influences all explosive movements (how fast the athlete can accelerate, decelerate and change directions, how high he can jump, how far he can throw an implement, etc.) and can make an athlete in dynamic sports a faster and more effective machine. In the initial analogy, explosive strength/power is the actual horsepower of the race car: assuming max strength determines the top speed the car can eventually reach (i.e. the max amount of force your body can produce independent of time), explosive strength/power would determine how fast the car can accelerate from 0-100 km/h (i.e. how much force/work can be produced in limited timeframes).

Track & field athletes exhibit awe-inspiring levels of explosive power, developed through years of performance-focused strength and power training.
While max strength is a more general and relatively more straight-forward parameter in terms of how it should be developed, explosive strength/power is much more dependent on the specific movements performed and a number of different physiological parameters need to be taken into account when designing the power development training program (whether the “weakest link” of the athlete is his max strength or his rate of force development, whether the particular sports movement requires explosive force production from a dead start or whether a stretch-shortening muscle action is involved, what the length of the timeframe for force application is in the particular movement, what the amount of load used is, what are the specific joint angles and ranges of motion, etc.). There is a vast array of different exercises that can be used to develop the athlete’s power production, including basic olympic lifts (e.g. power cleans and power snatches) for general hip extension power production, basic sprinting and jumping exercises, throwing exercises (e.g. med ball throws), various different plyometric exercises (e.g. bounds, hurdle work and depth jumps) and even basic strength exercises performed in an explosive manner (e.g. dynamic effort work with or without accommodating resistance modalities like resistance bands and chains). The job of a knowledgeable and experienced S&C coach is to create an effective power development program that factors in the specific physical condition of the athlete and the specific physiological and biomechanical demands of the athlete’s main sport.

Aerobic Power Capacity

The aerobic energy system can be described as the “default” energy system of the human body. It is the most energy-efficient energy system, burns energy substrates slowly and produces energy slowly (and can therefore produce low levels of power compared to the other energy systems) without creating any metabolic byproducts (and can therefore maintain a steady power output for very long periods of time). It is always turned “on”, which means that whether you are fully relaxed lying on your bed or engaging in high-intensity sports activities, the aerobic system produces power. Once the activity levels rise high enough that the muscle cells require more energy than what the aerobic energy system alone can produce, the anaerobic energy systems kick in to provide the additional energy required.

The value of increasing an athlete’s aerobic power capacity is twofold. On the one hand, the aerobic energy system provides “free clean energy”, meaning that it doesn’t significantly contribute to muscle fatigue (at least not when it comes dynamic sports; in very-long-duration endurance events this can obviously differ), as opposed to the anaerobic energy systems that contribute to fatigue via drop in muscle cell pH and/or substrate depletion. This means that, if the athlete can increase the power capacity of the aerobic system, the anaerobic systems will kick in later and will have to produce less power, resulting in delayed onset of fatigue. On the other hand, the aerobic system can act as sort of a “recharger” for the anaerobic ATP/PCr system, which can indirectly result in the athlete being able to engage in short bursts of very high power (e.g. short sprints and high jumps) more often and more effectively, and it may act as sort of a “cleanup crew” for the anaerobic glycolytic system “residues” (for more on this, have a look at this article), which can help with muscle pH level maintenance and indirectly result in a delayed onset of fatigue (more on the ATP/PCr and glycolytic systems in a bit).

The aerobic power capacity is dependent on a number of different physiological factors (cardiac stroke volume, muscle capillary density, mitochondrial size and density, myoglobin content and aerobic enzyme concentrations) and can therefore be developed via several different modalities (e.g. low-intensity steady-state, threshold, high-intensity steady-state and high-intensity intermittent training) of general or more sport-specific nature, that each target different specific adaptations. Effective S&C program design requires the coach to successfully diagnose the specific strengths and deficits of the athlete and take into consideration the specific aerobic energy system demands of the athlete’s main sport as well as the aerobic training stimuli the athlete already receives through training and competing in his/her main sport.

Aerobic power capacity can sort of be seen as the electrical power of a hybrid electric car (assuming the electrical power production system were entirely “free”, “clean” and virtually unlimited), that can provide a basic energy level entirely cost- and byproduct-free but can only produce up to a limited power level before the internal combustion engine needs to kick in.

The aerobic and anaerobic stimuli already received through main sport work need to be
factored in to the S&C program design.


Anaerobic Power Capacity

The anaerobic energy systems are the “higher power” energy systems of the body. They can provide energy to the muscle fibers faster, and can therefore produce a higher power output. There are two different anaerobic systems, a high-power/moderate-duration one (the glycolytic system) and a very-high-power/very-short-duration one (the ATP/PCr system). The glycolytic system is what provides energy as soon as the intensity levels get high enough that the aerobic system alone is unable to fully cover the energy demands, like in higher intensity running and repetitive jumps, and the ATP/ PCr system kicks in when maximal energy delivery is required for very explosive and very high intensity short bursts of activity, like a maximal jump, an all-out 40-meter sprint and a single squat repetition with maximal weight. The ATP/PCr system leaves no “residues” but is very short lasting (substrates will be depleted within 8-10 seconds of all-out activity and can take around 3-5 minutes to be nearly fully restored), while the glycolytic system can last for a lot longer but creates metabolic “byproducts” that lower the muscle pH and result in muscle fatigue.

The power of the very explosive ATP/PCr system depends mainly on neural and architectural parameters and is targeted through max strength and explosive strength and power work. The glycolytic system, which is an important factor in the endurance of athletes in most dynamic sports, is targeted through moderate and high intensity endurance work, like threshold, high-intensity steady-state, high-intensity intermittent and anaerobic power training. The duty of the S&C coach is to make a careful assessment of the fitness state of the athlete (e.g. the relative levels of development of the aerobic and anaerobic systems) and, taking into consideration the specific energy demands of the athlete’s main sport as well as the training stimuli received via their main sport work, determine the proper types and volumes of glycolytic system work.

Although there is no direct car analogy for the glycolytic system, it can sort of be seen as the gasoline in the hybrid car, that picks up the slack as soon as the electrical engine cannot fully power the speed/acceleration required but its quantity is limited and using it inefficiently may be counter-productive.

Movement Mechanics/Quality of Movement
Apart from the strictly quantifiable performance parameters mentioned above, the last main goal of S&C training is helping athletes develop proper movement mechanics and addressing any movement mechanics deficits. Correct mechanics are extremely important in athletic preparation because they increase the efficiency of movement and force transfer which can result in improved performance as well as reduced risk of injury (both when it comes to acute injuries, as well as injuries by overuse). Common fundamental movement mechanics issues can involve proper spinal alignment and proper pelvic position for safe and efficient force transfer from the lower (where the main generators of force are) to the upper body (through which force is applied in many athletic movements), proper knee-hip positioning and proper foot and ankle alignment during running/jumping/changes of direction, and proper scapular movement and shoulder stabilization during upper body force application (pulls, presses and throws), and should be a main priority of athletic preparation both in the younger ages (where fundamental motor patterns need to be gradually developed) as well as in the older ages (where any deficits need to be addressed). A careful and constant assessment of movement mechanics is required for high-quality athletic coaching throughout an athlete’s career, but the unfortunate fact is that, outside of certain sports that by their nature focus heavily on movement mechanics (e.g. gymnastics, olympic weightlifting and explosive track & field events), most sports coaches in most sports and across all levels of preparation are inattentive to movement quality in their athletes. Therefore, effective S&C training should aim to develop proper movement mechanics that will later transfer to a higher quality of movement and more efficient performance in the athlete’s main sport.

Good quality of movement is necessary for efficient performance on the field.
Effective S&C coaching requires constant attention to the athlete’s movement quality and experienced and knowledgeable coaches need to be able to readily discern gross motor pattern deficits in their athletes. A number of different factors can contribute to improper mechanics, from bad motor pattern imprinting and proprioception deficits (which are neurally-controlled procedures), to muscle strength and muscle length imbalances (e.g. imbalances between hamstring and quad strength, causing knee stabilization issues), to lacking joint range of motion due to shortened connective tissue structures (e.g. a tight/shortened posterior capsule in the shoulder joint, causing reduced overhead and internal rotation range of motion), to neural inhibitions and/or improper muscle activation patterns (e.g. glute inhibition, resulting in lumbar spine hyperextension during hip extension), to anatomical deviations (e.g. a greater Q angle in the knee or a fallen foot arch). The duty of the S&C coach is to maintain constant attention to the athlete’s quality of movement, diagnose any specific deficits and use specific training means to address them (proper training cues, gradual exercise progressions, targeted drills, specific assistance exercises, targeted stretching according to the main sport’s range of motion demands, etc.).

In the original analogy, one could say that proper movement mechanics is analogous to the mechanical maintenance (proper axis alignments, proper suspension system design, keeping the engine well-oiled, etc.) that is required for the race car to remain in top shape and effectively apply its engine power.

Injury Prevention/Injury Management

While “injury prevention work” appears to provide no enhancements in the athlete’s performance in his main sport, injury prevention is also one of the primary goals of S&C training, since it ultimately comes down to this simple concept: injured athletes perform bellow their peak potential (and seriously injured ones don't perform at all). Injuries are an unavoidable part of athletic activity (no amount of preparatory work will entirely eliminate injury risk in the case of a blind spot tackle), and S&C training should aim to reduce the risk of future injury as well as help manage and overcome existing injuries.

If the S&C program aiming at max strength, explosive strength/power, aerobic and anaerobic energy system, and proper movement pattern development, is properly designed and implemented according to the specific needs of the athlete and the demands of their main sport, injury risk reduction should by default be an indirect result of training. Due to the fact that, even under absolutely optimal circumstances, injury risk can never be entirely eliminated, injury management is also an inherent part of S&C training. An effective coach needs to possess good understanding of the basic science behind the myoskeletal injury healing processes as well as knowledge of the mechanisms of injury and healing timeframes for the injuries commonly encountered in the athlete’s main sport, and needs to be able to apply this knowledge in the athlete’s training.


Strength and conditioning training needs to have specific performance goals relating to the different physiological and biomechanical parameters that directly contribute to athletic performance. It needs to assess and factor in the specific fitness state of the athlete, his strengths and weaknesses in each parameter, his training history, his injury history and his individual biomechanical peculiarities, it needs to factor in the type and volume of stimuli already received through the athlete’s main sport work, and it needs to take into account the specific physiological and biomechanical demands of the athlete’s main sport. In order for strength and conditioning training to be effective, it needs to be designed and implemented in a way that it produces specific and quantifiable increases in the athlete’s max strength, explosive strength/power and aerobic and anaerobic power capacity, and result in specific improvements in his movement mechanics. Knowledge of the above is useful for coaches and athletes to make correct choices in their training.

Properly designed S&C training will help you build a more powerful athletic engine.