The words “aerobic capacity” and “met con” get thrown around a fair bit, but what does it all mean? All this damn jargon can be a wee bit confusing. Put simply, aerobic capacity is a measure of the ability of the heart and lungs to get oxygen to the muscles. In a testing situation (Vo2max), it’s the maximum amount of work an individual can physically do. Period. Metabolic conditioning (aka met con) is a structure of work & rest (exercises, rest periods etc) designed to elicit a certain response from the body. Differing work to rest ratios will call upon different energy systems which will develop adaptations that are specific to the training stimulus.
When we exercise, we breakdown our food for energy through the use of exercise metabolism. This form of metabolism is fuelled by a number of different pathways/energy systems; intensity & duration of the task in question will determine which system is then used. The three main systems are as follows;
Anaerobic Alactic – high power/short duration. High velocity actions that require short bursts such as sprinting, such as Olympic lifting, maximal jump efforts and heavy lifting (1-3RM).
Anaerobic Lactic – moderate power/moderate duration. Slightly longer actions such as a 200-400m, pressing in football, a long rally in tennis.
The Aerobic System – low power/long duration. It supplies energy for all low and moderate intensity activity such as jogging, walking, sleeping & resting (stuff we do an awful lot).
Within a sporting context, certain parameters/metrics will be put in place to ensure specific targeting of the systems that are typical within the given sport. However, an athlete whose sport is predominantly anaerobic, such as ice hockey will inevitably focus a lot of their work on improving anaerobic abilities but also improving overall cardiovascular capacity.
Aerobic Output
Targeted aerobic training can not only lend a helping hand with overall cardiovascular output, and performance within a training context but also in other areas too. Strengthening the ability of the aerobic system can help improve stroke volume – the delivery of oxygen to the rest of the body during exertion. This will essentially improve the level at which you’re able to work at helping resist fatigue for longer. Targeted aerobic work also helps with recovery when working at higher intensities such as; refuelling in between intervals, lactate clearance, and improving the ability of the muscle cells that use oxygen to produce intracellular energy for muscular contractions - making it a stronghold in between heavy lifting sets. Lastly, aerobic work can assist with general recovery by improving the flow of oxygenated blood to muscle tissue. There is a whole myriad of factors that also contribute towards getting optimal recovery but implementing low intensity (55-60% max heart rate) aerobic can help.
How To Improve Your Capacity
This is where that 80/20 rule comes in again - 80% of your training should be performed at intensities just below lactate threshold - level at which lactate begins to accumulate above resting levels and clearance can no longer keep up with production. The remaining 20% comprised of working at onset of blood lactate - the level at which lactate begins to accumulate past lactate threshold - where the fun stuff happens! This can be pretty hard to monitor within a training context without the necessary equipment and a thorough understanding of one’s body. An easier way is through the use of heart rate zones. For optimal capacity work, sessions should be completed at a minimum of zone 2 (140-150) and should include repeated efforts in zone 3 (150-160), zone 4 (160-170) and zone 5 (>170). Use a work to rest ratio of 1:1 (for every second you work, you rest for 1).
High intensity training (HIT) is also a useful tool for improving aerobic capacity (when executed correctly). Intensity is key to the success here - too low, and you won’t target the correct system and get the necessary adaptation…too high, and may struggle to finish the workout. When trying to establish the right intensity, it needs to be a bit of kit/movement that you can execute proficiently, but more importantly in a fast manner.
In order to maximally activate your anaerobic alactic system, an all-out effort lasting up to 10 secs is required. Once this system is depleted, it needs to be replenished by either the lactic or aerobic system. As a result, a work to rest ratio of 1:4/5 should be utilised. So, for a 10 second effort, rest between 40 and 50 seconds. To activate your anaerobic lactic system, use a work to rest ratio of 1:3 (for every second you work, you rest for 3). Exercise duration should be 30 to 60 seconds, so recovery will be between 90 and 180 seconds. When trying to increase the intensity of a workout, increase duration but don’t meddle with the work to rest ratio. If the ratio goes below the stated amount, the chances are power output will be jeopardised causing the work to become more aerobic.
The rise of boutique gyms & classes over the years has seen an increase in the use of HIT, and all the wonderful marketing & buzzwords that go with it. Whilst HIT provides many benefits, it’s also extremely taxing on the body. The post exercise calorie expenditure is huge with this type of training making it an effective, and appealing tool for burning fat but when overused can unearth undesirable outcomes if the individual is predisposed to unmanageable doses e.g. metabolic & neural stress/fatigue, overuse injuries etc.
The effects that aerobic and anaerobic training have on the body vary greatly; aerobic development increases stroke volume, anaerobic decreases it. Aerobic training stimulates the parasympathetic (rest-and-digest) nervous system, anaerobic training stimulates the sympathetic (fight-or-flight) nervous system. Put simply, the adaptations you’re trying to achieve from each system are in direct competition with one another. A successful training program will tailor conditioning sessions to meet the needs of the individual/athlete, but also manipulate variables depending on concurrent training volumes & emphasis. If your aim is to get fitter and stronger, you want both training approaches to be complimenting one another, not clashing and blunting progress. If you’re constantly burning the candle at both ends plying the body with high training stresses (heavy resistance training, high intensity training etc) with little plan throughout the week/month, then the chances of burning out will be increased.
To sum, having a strong aerobic capacity can assist in a number of different ways. Use an array of intensities and durations to enhance development. Use HIT to compliment capacity growth but don’t solely rely on it. Establish the right intensity but don’t overdo it – sessions that are too long or intense may attenuate glycogen recovery and may impair strength development. Try alternating between high and low intensity volume training stressors to allow the mind and body to recover. Try implementing moderate intensity aerobic work on recovery days. Have a plan and stick to
