All sports and activities exist on a continuum, drawing more or less on the anaerobic and aerobic energy systems. Picture: SERGEY NIVENS/123RF
All sports and activities exist on a continuum, drawing more or less on the anaerobic and aerobic energy systems. Picture: SERGEY NIVENS/123RF

One definition of insanity is doing the same thing over and over again but expecting different results. This overused pop-culture quote, misattributed to Albert Einstein, holds a lot of truth for many people who spend hours, weeks and months exercising yet find they’re going nowhere slowly.

Think about this: have you ever seen a father who runs 10km every Saturday attempt to play a game of touch rugby with some of his son’s mates? More often than not, within five minutes he is crouched over his knees saying something along the lines of: “I’m getting too old for this nonsense.”

Or the fitness-fanatic mother who feels physically dead after a child’s jungle-gym party; or her oiled-up bodybuilding brother who can barely breathe after chasing an umbrella 30m down a windy beach?

We have three systems that produce the energy we need to perform exercises or partake in our favourite sport. Two are anaerobic, meaning they don’t require oxygen and they power short bursts of activity, and one is aerobic, meaning it requires oxygen and it powers longer-duration exercise.

The two parents and their bodybuilder brother may exercise regularly and feel they are “fit”. However, in all likelihood they have not been training across all energy systems sufficiently.

Nothing exists in isolation. There needs to be a solid base of aerobic fitness and muscle strength, after which some focused attention on specific systems can unleash a new level of desired performance for the sporting activity you love, or love to hate.

All sports and activities exist on a continuum, drawing more or less on the various energy systems. Some sports — such as rugby, boxing or other high-intensity, interval-type activity — will require high degrees of anaerobic proficiency built off a very strong aerobic fitness base. This is in contrast to marathon running, which will rely more heavily, though certainly not exclusively, on aerobic capacity.

So, what are these energy systems?

Chad le Clos of South Africa competes in the Men's 100m Butterfly heats during day six of the Gwangju 2019 FINA World Championships. PICTURE: MADDIE MEYER/GETTY IMAGES
Chad le Clos of South Africa competes in the Men's 100m Butterfly heats during day six of the Gwangju 2019 FINA World Championships. PICTURE: MADDIE MEYER/GETTY IMAGES

The anaerobic, phosphocreatine system uses adenosine triphosphate (ATP) — which is primarily stored in muscle cells — for energy and can operate in the absence of oxygen. It produces a high amount of maximal energy, quickly. Think a few seconds. Once the ATP stores are depleted, the tank needs to be refilled before you can go again.

The glycolytic or lactic acid system produces energy from muscle glycogen, which can happen with or without oxygen. Without oxygen, or with inadequate oxygen, a series of chemical reactions that produce ATP (for energy) produce a burning byproduct we have all experienced: lactic acid. This system fuels high-intensity training for up to a few minutes, after which, if you are like the author of this article, you roll around in agony.

As the name implies, the aerobic system operates in the presence of oxygen and generates energy through the breakdown of glucose and fatty acids. This system delivers energy for lower-intensity exercise over longer periods.

You use your various energy systems when training or competing. An online training resource for cyclists, Semi-Pro Cycling, says you can conduct an experiment on yourself to experience the interplay between the three systems. Imagine you are on your bicycle and decide to go for an all-out sprint.

While the times mentioned in their estimate are a broad indicator, they help explain the interplay between the energy systems. The first 10-15 seconds is fuelled almost entirely by the phosphocreatine system, producing a huge burst of power, but you tire very quickly, Semi-Pro Cycling says on a blog entry detailing the energy systems.

“After around 10 seconds the [phosphocreatine] system is completely exhausted and the lactic acid system starts to kick in. By 30 seconds, the lactate system has fully taken over but rapidly starts to fatigue as lactic acid accumulates. By 40 seconds, the aerobic system has begun to kick in as oxygen has made it to the working muscles and begins to assist with the aerobic contribution of energy production,” the article says.

If you cycled at a low intensity only, you would be drawing on your aerobic system. But in the real world, there are hills and varying degrees of intensity and so you see how the three systems support each other.

Mona Pretorius of SA competes in the women's 58kg group A weightlifting event at the JN Sports Complex at the Delhi 2010 Commonwealth Games. PICTURE: CAMERON SPENCER/GETTY IMAGES
Mona Pretorius of SA competes in the women's 58kg group A weightlifting event at the JN Sports Complex at the Delhi 2010 Commonwealth Games. PICTURE: CAMERON SPENCER/GETTY IMAGES

The good news is that you can focus your training to improve the efficiency of the various energy systems. If you have a low lactate threshold and are weak in the high-power output zone, there are training protocols that will improve your anaerobic performance. Improvements in energy system efficiency will depend on your neuromuscular system’s ability to withstand stress, tension and fatigue. It is about training smartly.

Neil Murphy, a sports scientist who has worked with the Golden Lions junior rugby and Vodacom Cup teams and finished a four-year stint at the Griquas as a sports scientist and scrum coach, says that there has to be a solid foundation.

A sports scientist at Jim Fouche High School, Murphy emphasises the importance of aerobic fitness and muscle strength before trying to improve the efficiency of the various energy systems.

“If there is no strength base, there can be no source from which to draw the power. You have to take into consideration the recruitment of muscle fibres. What will you be converting to speed for your high-intensity movement? That base has to be there.

“However, don’t think you can ignore cardiovascular exercise. You must have a set foundation of aerobic capacity to allow the other two energy systems to work properly. This is vital for the anaerobic systems, because what drives your recovery is your aerobic capacity.”

While serious competitors and their coaches know all of this, being aware of the different energy systems allows more casual or part-time athletes to understand how they are drawing energy and where they are lacking in terms of conditioning.

Rob Labuschagne, physical practice coach and GM of gym and exercise supplier MiFitness, says that to start with, all training should incorporate all three energy systems. “You would then alter your training protocol to use the specific system required in your sport so that you become more efficient in the production of energy and power specific to that sport.”

A balanced protocol of strength training, high-intensity training and endurance work will give you the best chance of burning excess calories and leaning down.
Ilana Bellotto

Ilana Bellotto, owner of The Fitness Niche, which is a women’s personal training and fitness company, says she often gets clients who have spent years focusing on one exercise type and have “hit a brick wall in their training”.

“Sometimes a new woman will join with fairly decent aerobic fitness but has done zero strength or higher-intensity training. Once we rectify this, the brick wall becomes a launch pad to another level of performance and results,” Bellotto says.

Labuschagne agrees, saying that even for non-athletes, the benefits of training across energy systems are well worth it. “A balanced protocol of strength training, high-intensity training and endurance work will give you the best chance of burning excess calories and leaning down.”

Ultimately, every sport or activity has its own specific parameters and requirements regarding strength, short-burst power intervals and longer duration output. Training specialists understand this and apply the principles in daily training programmes to maximise efficiency for the chosen activity.

In competitive sport, it ramps up a level. A glance at the training protocols of Murphy’s rugby-specific conditioning — targeting the performance zones critical to a rugby player — demonstrates the depth and focus that competitive training requires.

Rugby requires training across the various energy systems. According to Murphy, players must train their strength and power (the phosphocreatine system); their alactic capacity (the glycolysis system and lactic acid tolerance); and their aerobic power. This training happens in addition to their actual rugby skills and game drills.

Players in different positions have different roles, but all rugby players must be strong, quick and fit. A rugby player needs to be able to accelerate quickly from a standing (or lying) start, sprint with the ball and endure being tackled and slammed into the ground. Over and above these two requirements, the player is expected to do all this for 80 minutes.

The following summary will provide a glimpse of the type of energy systems training that would suit a rugby player:

SA ultramarathon runner Bongmusa Mthembu during in the Comrades Marathon. PICTURE: AMESH DEBIKY/GALLO IMAGES
SA ultramarathon runner Bongmusa Mthembu during in the Comrades Marathon. PICTURE: AMESH DEBIKY/GALLO IMAGES

To improve strength, their training will include squats, bench press, dead lift, pull-ups, sled drags and “strongman-type” exercises. To target power, their training will include jumps, sprints, medicine ball throws, and Olympic lifts and their variations.

They will typically do two to three sets of five repetitions at 70% to 90% of their one-rep max (the amount of weight they can use for one repetition). This will be done for two to three exercises, and be repeated two to three times a week.

To work on their alactic capacity, their training may include barbell complexes, kettlebell exercises, sports-specific drills, powerlifting moves and sprints. This training will typically be done at a high intensity of 10 minutes’ work, followed by five minutes’ rest, repeated a few times. Once or twice a week they may also do high-intensity training of 20 seconds or less followed by 20-60 seconds of jogging or skipping.

To improve their aerobic power they will do exercises that include boxing, body weight exercises, rowing, cycling, running, kettlebell exercises and skipping at medium intensity of two minutes on, with one minute’s rest, repeated six to 12 times, once or twice a week.

A cursory understanding of the basics around how you draw your energy could well be the difference between finally finishing the 947 in the time you have targeted and spinning your wheels aimlessly for another year.

As is evident, the three systems for generating energy exist on a continuum. The kind of training that a competitive rugby player needs to improve his aerobic power relevant to his sport is different from the focused training that would go into conditioning a marathon runner. A medium-intensity aerobic workout for an elite athlete may well feel like a high-intensity, all-out session for a casual trainer.

Understanding that we have these different energy systems allows us as fitness and sports enthusiasts to analyse the type of movements that our activity of choice draws on most. Once we have a solid foundation of mobility, strength and aerobic fitness in place, we can focus our training in the zones that would benefit us most.