Conditioning for Sport Performance◆ ☕️☕️☕️ 17 min read
- Aerobic System Development
- Lactic System Development
- Alactic System Development
- General Programming Principles
Your body needs a constant supply of energy to keep you alive. To meet the energy demands, your body has energy systems.
Conditioning is a term that is often badly defined but it’s simply a measure of how well an athlete is able to meet the energy production demands of their sport.
In the simplest terms, your body uses two primary energy pathways. Aerobic that requires oxygen, and anaerobic that doesn’t require oxygen. Both of those systems generate ATP, adenosine triphosphate, which is the currency of intracellular energy transfer.
The environment encountered will determine which type of energy pathway is primarily used to meet the energy production demands.
The variables that affect the environment in terms of energy production demands are:
- Work-to-rest ratio.
Each energy system has a power and a capacity component.
The power component relates to the rate of energy production of the system. This implies how rapidly ATP is regenerated during the period of work. High rate of energy production means high power output, which indicates that the anaerobic system is the dominant energy supplier. Sport examples include weightlifting, powerlifting, and different explosive jump, sprint, and throw events in track and field.
The capacity component relates to the duration of energy production the system can maintain at a certain work level. This implies to economy and efficiency. Long durations of energy production mean aerobic energy system dominance. The extreme examples of this are marathon and triathlon.
Power and capacity are related to the force-fatigability relationship. This implies that as the maximum rate of energy production (power) increases, the maximum duration of energy production (capacity) decreases and vice versa. There is a trade-off between the duration of the activity and the amount of power you can exert.
Work-to-rest periods simply mean the difference in length between work and rest intervals. Higher peak power with longer rest periods indicates more anaerobic contribution, whereas shorter rest periods or longer work periods result in greater aerobic contribution.
All 3 of those factors will inform the prescription of training methods.
What is important to note is that the energy systems turn on and work at the same time, not in isolation, but the contribution of each system towards the total energy production will vary, as power, capacity, and work-to-rest period characteristics of the activity are manipulated.
Different energy systems vary in their capability to produce ATP and can manage that for different durations of time at different rates.
There are two anaerobic systems, the lactic (glycolysis) and alactic (phosphocreatine hydrolysis) systems. It is beyond the scope of this article to go into the underlying mechanisms of energy production for those systems. In the simplest terms, these systems are mainly used for short duration activities that require high power output as they don’t rely on oxygen, but they can only produce energy for a short period before fatigue sets in.
The aerobic system is way more efficient and capable of producing power for a much longer duration without fatiguing, but the power output will be lower. This is the system you predominantly rely on for energy production during rest and everyday activities.
The contribution of the aerobic energy system to energy production increases over time.
During all-out maximum effort high intensity activities, the crossover to aerobic dominance occurs in ~20-30s. In continuous efforts lasting longer than ~60-75s, the majority of energy is provided by the aerobic energy production.
During repeated activities, like intervals, each subsequent interval becomes more and more aerobic as the activity is repeated. This is why you continuously slow down with each repeat. As such, it shouldn’t come as a surprise that most team sports have a huge aerobic component to them, even if explosive movements are a crucial part of the activity.
Energy systems development determines the balance and trade-off between strength/power and endurance or the ability to maintain strength/power.
Different athletes are able to produce a different amount of power anaerobically versus aerobically. The difference is called the anaerobic speed/power reserve. It is the portion of your maximum speed/power that is not produced from your aerobic energy system. In other words, it is the difference between your absolute maximum speed/power output and the maximum speed/power you can produce aerobically at VO2max (maximum oxygen uptake).
The anaerobic speed/power reserve can help predict how fast you will fatigue. If the athlete has a larger component of energy coming from the aerobic system as opposed to the anaerobic, they will be able to maintain the speed or power output for longer. The more an athlete relies on anaerobic energy production, the faster they will fatigue.
Aerobic System Development #
The capacity to improve the aerobic system is greater than that of the anaerobic systems.
Training intensity is of relevance here. In general terms, high intensity training provides a stronger stimulus for the body, which means that initial training adaptations might happen quicker than with low intensity training. But consistently training at a high intensity will increase the probability of plateaus and overtraining.
Moderate and low intensity training produce less significant adaptations in the short run but will result in greater and longer lasting improvements in the long run. Therefore, aerobic training shouldn’t be overlooked.
Aerobic Power Intervals #
Aerobic power intervals are geared towards increasing the strength and contractile abilities of the cardiac muscle tissue through intense work. The overarching aim is to increase the amount of blood the heart can pump, which is achieved through how forcefully the heart can contract with each beat. This is also related to a corresponding increase in mitochondria, which improves the heart’s endurance at high heart rates. A stronger heart with more mitochondria is less likely to fatigue at higher intensities and is capable of delivering more oxygen.
- 60-180s at 100% VO2max
- 1-3-minute rest period (doing more repetitions might require slightly longer rest periods, or base your rest off of HR recovery to 120-130bpm)
- 4-15 repetitions
- 1-2 times per week
- Any high intensity exercise that maximally elevates the heart rate is relevant to use. Think sprinting and sport-specific high intensity drills
Aerobic Capacity Development #
Aerobic capacity development is what is often called the “steady-state” aerobic work. Again, the aim is to improve how much blood the heart can pump with each beat. The clueless high-intensity interval training (HIIT) wizards might argue that HIIT is more efficient than doing low intensity work. But aerobic capacity work develops the heart and the vascular network in a way that higher intensity intervals aren't able to.
Longer low intensity work aims to increase stroke volume (the volume of blood pumped with each beat), achieving that by increasing the size of the left ventricular cavity of the heart, as opposed to increasing the contractility of the heart like aerobic power intervals do. The mechanism for this is called eccentric cardiac hypertrophy, where the heart adapts by stretching, thus leading to a larger left ventricular cavity that is capable of pumping out more blood. Aerobic power intervals result in concentric cardiac hypertrophy, which leads to the thickening of the cardiac wall, but not necessarily to an increase in the cavity volume. As such, aerobic capacity work should precede aerobic power intervals, with the intervals building on and complementing the adaptations of the capacity training.
The adaptations associated with aerobic capacity work make it essential to maintain a lower heart rate during training. Heart rate in the range of 120-150bpm is usually recommended. Older, less fit individuals should aim for the lower end of this range, with younger healthier people aiming for the upper end. If the heart rate goes too high, the contractions become too fast to provide for an adequate eccentric overload stimulus.
Aerobic capacity work also develops the vascular network, increasing oxygen transport to the working muscles. To really increase capacity of the aerobic system, more training volume than a 20-minute HIIT session could provide is required. That is another reason why HIIT is just not comparable to aerobic capacity work. One does not replace the other. Both higher and lower intensity energy systems work is required.
- HR at 120-150bpm
- 20-90 minutes of work, can increase volume over time
- 1-3 sessions per week
- Any low intensity exercise is relevant as long as the HR is kept in the appropriate range. Think jogging, cycling, rowing
Lactic System Development #
The anaerobic lactic system is able to produce much higher rates of ATP than the aerobic system, but it cannot sustain it for long. Anaerobic work is what is often associated with fatigue and the burning sensation you might feel in your muscles after a brief work period at the absolute maximum intensity. One cause for this is thought to be the accumulation of byproducts associated with anaerobic energy production. I will deliberately not get into the discussion of what causes muscular fatigue, as this is a complex topic deserving of a separate article.
The anaerobic lactic system has less room for overall improvement when compared to the aerobic system. Additionally, lactic system adaptations will conflict with those of the aerobic system. As such, they can’t both be maximally developed at the same time. There will always be a trade-off between power and endurance.
Further to this, the adaptations of the lactic system tend to level off in ~4-6 weeks of training. This does not mean it's not a good investment to train it, but it should be emphasized during appropriate stages of training to get the maximum benefit.
Determining the relevance of the lactic system to your specific sport will provide insight into how much this system needs to be developed. For example, sports that require repeated-sprint ability, like field sports, rely mainly on alactic-aerobic energy system demands. As will be discussed below, the alactic system provides the immediate energy for the high intensity activity, while the aerobic system works on substrate recovery between the sprints.
In this case, the emphasis on glycolytic development can lead to sub-optimal aerobic conditioning, which will take away from the performance of the athlete, as the majority of the metabolic demands come from the alactic and aerobic systems. Unfortunately, both the European and American systems still to this day rely on running athletes into the ground. High-intensity is thought to be the name of the game and you have to consistently push through the pain in training to be a successful athlete. If you crumble, you were never good enough in the first place. In reality, this is far from the truth.
The key is an appropriate balance between the energy systems. One is not better than the other. Too much lactic development will lead to early exhaustion in a performance scenario. Too much aerobic work will result in the lack of power and explosiveness that is a requirement for many sports.
Lactic Power Intervals #
As the name suggests, this training method aims to increase how much power your lactic system can produce. An universal key to power development is maximal intent. The activity will have to be performed with 100% effort and intensity to improve the system’s maximum power generating abilities.
If sprints, jumps, or throws are chosen for this type of training, all of this will have to be done with maximal intent on every single repetition. If sport-specific drills are chosen, these will have to be done in a similar fashion.
This method stimulates increase in the enzymes involved in lactic metabolism, specifically phosphofructokinase (PFK) and phosphorylase.
- Maximum intensity intervals of 20-40s with maximal intent
- Up to 4 minutes of rest (can be active rest), or as long as necessary to perform at the highest power output again
- Can complete repetitions in sets, with up to 3 repetitions per set, for 2-4 sets per workout, with 8-15 minutes of rest between the sets to adequately recover
- If chosen to just do repetitions, the rest periods might have to be lengthened appropriately for each subsequent repetition to minimize fatigue accumulation
- If the repetitions are rushed and recovery is not adequate, the training adaptations will be sub-optimal
- 1-2 sessions per week
Lactic Capacity Intervals #
This is similar to lactic power, but the work and rest periods are manipulated to focus on increasing how long you can maintain lactic power instead of increasing your maximum power output.
The shift from power to capacity requires longer work intervals with shorter, incomplete, rest periods.
This method will train the body to buffer the mechanisms of muscular fatigue that are associated with the use of this energy system, prolonging the ability to continue producing ATP with the lactic system. Lactic capacity work also has the potential to increase glucose storage and utilization potential.
- Similar principles as for lactic power
- Maximum intensity intervals of 40-90s or up to 120s with maximal intent
- 1-2 minutes of rest (incomplete rest)
- 3 repetitions per set for 2-4 sets per workout can again be used, with 4-6 minutes of rest (can be active rest) between sets
- 1-2 sessions per week
- Aim for complete fatigue
Alactic System Development #
The anaerobic alactic system generates ATP at even higher rates than the lactic system. As such, it can also produce a level of overall fatigue. The alactic system, however, is limited to very short bursts of explosive power output, which also means that its contribution to muscular fatigue is a lot lower than that of the lactic system.
Between those short explosive bursts, the aerobic system works on the back-end to regenerate the necessary substrates and remove the metabolic waste products produced. Thus, the aerobic system interacts with the alactic system, dictating how much fatigue results from the use of the alactic system.
A variety of sports can call for situations in which immediate, maximally explosive actions are required in-between periods of lower intensity activity. For this to occur successfully, the alactic system has to be ready to provide ATP at an extremely high rate, or the explosiveness will not be reached.
Therefore, the aerobic system plays a crucial role in eliminating the waste products and regenerating the substrates required for the alactic system to generate explosive power. As such, a well-developed aerobic system is essential to make maximal use of the alactic energy system.
Considering all of this, the aim should be to maximize how much power the alactic system can produce while improving how fast the aerobic system can refuel the alactic system for repeated use.
Alactic energy system is the least trainable of the three energy systems. But there is still some capability of improving alactic power and capacity.
The power adaptations come from an increase in specific enzymes, like creatine kinase, which is responsible for accelerating the breakdown of phosphocreatine essential for alactic system function. The faster the chemical reactions can occur, the more power the system will be able to generate.
The capacity adaptations are largely dictated by how much ATP and phosphocreatine the muscles themselves can store. The more can be stored, the longer will this system run.
Since the alactic system provides energy for less time than the other 2 systems described above, the training methods utilize the shortest and most explosive periods of work out of the 3 systems. Again, maximal intent is key in both alactic power and capacity adaptations.
Alactic Power Intervals #
This method is aimed at increasing how fast the alactic system can produce ATP, by increasing the number of enzymes involved in its energy production. The more ATP it can produce, the more explosive potential you will have to work with.
If the athlete needs more explosiveness, it is important to realize that this type of training should go hand in hand with a thought-out and progressive resistance training plan focusing on all around strength and power.
- Maximum intensity intervals of 7-10s with maximal intent
- 2-5 minutes of rest or as long as necessary to perform at the highest power output again
- 5-6 repetitions per set for 1-2 sets per session, with 8-15 minutes of rest (can be active rest) between sets to ensure adequate recovery
- 1-3 sessions per week
- Any repetitive explosive exercise can be used, such as sprints, jumps, and max-effort sport-specific drills
Alactic Capacity Intervals #
This method aims to improve the capacity of the alactic system by increasing the amount of stored phosphocreatine. Whereas this might be one of the least trainable aspects of energy systems in general, the alactic capacity work helps to develop the beneficial rapid aerobic recovery, so this type of training is still relevant.
Again, to train capacity, the system has to be taken to its energy production limits. To achieve this, the work periods are lengthened, while the rest periods are shortened.
- Maximum intensity intervals of 10-15s with maximal intent
- 20-90s of rest (incomplete rest, can be active)
- 10-12 repetitions per set for 2-3 sets, with 8-10 minutes of rest (can be active rest) between sets
- 1-3 sessions per week
- Any repetitive explosive exercise can be used, such as sprints, jumps, and max-effort sport-specific drills
General Programming Principles #
Before you start implementing the outlined training methods, it makes sense to establish a baseline to be able to track your progress.
Some of the ways to measure and track your aerobic fitness include resting heart rate, heart rate recovery, or something like a classic 12-minute Cooper test.
Getting your resting heart rate lower reflects that your heart has become more efficient in its function. This is also reflected by an improvement in heart rate recovery, which implies to the rate of decline in heart rate after the end of exercise. Acceleration in heart rate recovery reflects improved aerobic fitness. In terms of the Cooper test, it’s just an easy test to see how far you can run in 12 minutes. If the distance improves, your aerobic fitness has improved. Plain and simple.
Assessing anaerobic fitness is in many ways even more straight forward. In case you’ve got access to some type of a power measuring tool, like on a stationary bike, you can easily test your power outputs over different lengths of maximal activity. You can do power output over 3-6s for alactic power, over 6-10s for alactic capacity, and over 30-40s for lactic power, just to provide some examples.
Having systems in place to assess your progress is crucial to establish the effectiveness of your training approach.
In terms of general training principles, you should always have a long-term plan for energy system development that accounts for the phases of the competitive season of the specific sport.
One way, suggested by Joel Jamieson, to periodize conditioning training is by splitting the year into 4 distinguishable phases of general (base) development, specific development, pre-competitive, and competitive.
General Development #
This phase is focused on building a base. General development might emphasize aerobic capacity and subsequent complementary aerobic power work. The movements chosen aren’t concerned with replicating the sport’s skill. The focus is on general training means to achieve central adaptive changes.
Specific Development #
Specific development phase moves towards sport specificity. The movements chosen start to incorporate the same muscle groups as the sport. The majority of energy production work comes from the energy systems dominant in the specific sport and in line with the demands of the sport.
The pre-competitive phase is concerned with increasing specific work capacity to prepare the body for the upcoming competitive season. The individual skills of the sport become primary exercises used in training.
The competitive phase focuses on using the sport itself as primary training means. Focus is set on competition specificity, with non-specific work only used as accessory training.
Within each of those phases, the high/low training model could be used. This approach is based on the concept that high intensity and low intensity training days are alternated. For example, you could have a high intensity training day on Monday, low intensity on Tuesday, and back to high intensity on Wednesday and so on depending on how many training days per week you choose to have.
According to this training model and in relation to what has been described above, all the high intensity interval work would be done on the high days, whereas aerobic capacity work is suitable for the low days.
The high/low training model is a considerable option for sports that require concurrent development of several different characteristics. The way the high and low intensity work is alternated minimizes the need for specific deload training weeks, as when programmed properly, the accumulation of fatigue is reduced considerably in comparison to a periodization plan that might have consecutive high intensity training days.
Generally, not much time should be spent at the moderate intensity level, as the middle ground often leads to high levels of fatigue without much improvement in actual conditioning. If this type of work is to be included in the high/low training model, this work should be done on the high intensity days due to the amount of fatigue it induces.
This is further emphasized by the above discussion on how the aerobic and alactic systems interact, and how the adaptations of the lactic system can stall within 4-6 weeks of training and shouldn’t be used extensively throughout the annual plan, but rather at strategically determined points in the plan, as lactic development still plays a crucial part in most sports.
Obviously, these ideas are still very general and informed decisions need to be made based on individual athletes and the specific demands of their respective sports.
There are many other training strategies to be discussed in relation to energy systems development, but the article is already extensive as it is. The above explained methods are a good starting point to organize your conditioning training and will set you up for success in the long run.
The majority of what has been discussed above has been taken from Joel Jamieson, who has extensive knowledge in the conditioning field. In case you want to dig deeper on the concepts, familiarize yourself with his content.
Alternatively, you could look at the work of some of the old legends in the field. The presented ideas are nothing new or revolutionary. The likes of Yuri Verkhoshansky, Vladimir Issurin, and Charlie Francis have described the same concepts decades ago.