This blogpost will cover principles of aerobic training building off of the principles of exercise reviewed in a previous post (Blog #2, Principles of Exercise). Remember, those principles include specificity, variability, overload, progression, recovery, reversibility, and periodization. It’s a lot to remember, but the key is to reflect and review when your training program isn’t working how you would like it to. This applies to all aerobic activities.
Factors Affecting Aerobic Endurance Performance
The three main factors you should be aware of that affect performance are maximal aerobic capacity, lactate threshold, and exercise economy.
Maximal Aerobic Capacity (VO2 Max)
A high correlation exists between aerobic performance and VO2 max of an athlete. This is the ability of the athlete’s body to meet the energy demands of the activity they are performing with aerobic metabolism (using oxygen). The better their body is at staying at a steady state (minimizing fatigue of muscles and utilizing fat as fuel source), then the longer they can maintain the pace. So clearly being able to sustain a high pace for high amounts of time will lead to improved performance.
HIIT workouts, high intensity interval training, allow individuals to improve their VO2 Max. This will be discussed more in-depth in a future blog post.
Lactate Threshold
This is the highest percentage of someone’s VO2 max before they start accumulating lactate. Lactate is produced by muscles when they can’t produce enough energy using oxygen. The lactate is converted to lactic acid and results in muscles fatiguing + becoming less efficient. This happens at different percentages of VO2 max depending on the individual, and can be even more indicative of who will win a race.
The lactate threshold can be trained by performing exercise near the threshold as the body will adapt by being able to clear lactic acid more efficiently. The threshold is when these removal mechanisms are overwhelmed by the amount produced by the cells, which increases with intensity.
Exercise Economy
This is the amount of energy cost at a specific pace. So if two people are walking/running/biking/swimming at X velocity, but one is expending less energy, that is the person that has better exercise economy. This can be affected by training of technique and a variety of other factors depending on the activity type. This can be trained simply by practice and consistency.
Aerobic Training Design Principles
The 5 principles or aerobic exercise include exercise mode, training frequency, training intensity, duration of training, and progression. Here we will discuss how they apply to an aerobic training program.
Exercise Mode
This is the activity, for example: biking, swimming, running. You want to be specific to the goal of training so you can improve muscular strength in the specific muscles and improve exercise economy by improving efficiency/technique. Cross training is also important to avoid overuse injuries.
Frequency
This depends on the intensity and duration of exercises, the training status of the individual, and periodization. It takes a higher frequency to improve training status than it does to maintain training status. It is understood that training at least twice per week will help individuals increase their VO2 max. It also is important to allow for more recovery days and lower frequency with beginners. Recovery is critical to allow the body to adapt to a training stimulus and get the most bang for your buck out of each training session.
Intensity
Increasing intensity generally reduces duration of a workout, however its necessary to increase cardio and respiratory function with improved oxygen delivery to working muscles. It also helps increase muscle fiber recruitment and strengthen type II muscle fibers (the ones responsible for higher power output). VO2 max is the best way to measure intensity, but heart rate correlates closely to VO2 max percentage as you can see:
% VO2 Max | % Max Heart Rate |
50 | 66 |
60 | 74 |
75 | 85 |
85 | 92 |
100 | 100 |
Max heart rate can quickly and easily be estimated by subtracting age from 220. So if you are 25, your max heart rate is likely around 195 BPM.
Duration
Usually training above lactate threshold (around 85% VO2 max) will have a relatively short duration due to fatigue, around 20-30 minutes. Exercise at lower intensity around ~70% VO2 max can be sustained for several hours before fatigue is experienced! That intensity is different for a lot of people, so you can imagine an untrained person will achieve this level of intensity doing much less than an experienced aerobic athlete.
Progression
Progression can be made by increasing duration, intensity, and frequency; however, the main rule is to try limiting progression by 10% or less with at least one active rest day to allow the body to recover. That means if you ran 10 miles at a given intensity, try not to run more than 11 miles the next week at that same intensity. As we discussed before with periodization, you want to make sure you have an easier week every third or fourth week to allow your body to catch up when in a training program.
Types of Endurance Training
When you manipulate the above factors, you will be able to train within specific categories of aerobic training: Long slow distance, pace/tempo, interval, high intensity interval, and fartlek. The frequency I list for each type takes into account that you are resting and performing resistance training on the other days of the week! This is very important to remember for injury and overuse prevention.
Long Slow Distance
When I was training for my marathon, these were the ones I did not want to miss because they trained my aerobic capacity to increase duration of a certain intensity. You want to maintain ~70% of VO2 max (80% max heart rate) and train between 30-120 minutes or longer depending on the goal. These are best to perform 1-2x/wk.
Pace/Tempo
This is at the lactate threshold intensity (85% VO2 max or a little above 90% max HR) and should be sustained for 20-30 minutes. This helps you train for increasing your lactate threshold where the aerobic and anaerobic energy mechanisms are both working. This is generally race pace and important to regularly include for training programs. Good to perform 1-2x/wk as well.
Interval vs HIIT
These are runs close to max heart rate and VO2 max about 3-5 minutes in length with rest periods at the same length. This results in a work:rest ratio of 1:1 where you are pretty much walking or slowly jogging for the same duration you are maintaining the high speed. This is because you are above max heart rate and cannot sustain the pace aerobically. The muscles fatigue and you can no longer maintain the previous pace, so you rest in order to allow the body to do it again.
High intensity interval training is a little different in that you are running greater than VO2 max; you’re basically sprinting. This will tire you out more quickly and require more rest, so the work rest ratios are usually around 1:5 with sprints lasting 30-90 seconds and rest breaks 2.5-7.5 minutes in between each sprint. One of either type is a good frequency per week.
Fartlek
These runs last 20-60 minutes and include intensity between long slow distance and pace/tempo speeds. This is a combo of multiple components and can help reduce boredom with running only a certain speed while improving VO2 max, lactate threshold, and exercise economy. This is also best about once a week.
Important Considerations
To avoid injury, some terms to be familiar with include cross training, detraining, tapering, and resistance training.
Cross Training
You always want to be careful with starting a new training program because your body is not used to the stresses you are about to incur on it. Cross training allows you to continue improving or maintain your aerobic fitness by changing the exercise type. If you are a marathon runner, swimming every now and then will help reduce the amount of strain on specific parts of the body and let the running muscles recover while preventing the effects of detraining. This is also true if you are injured and can’t run but can still do something lower impact.
Detraining
Detraining happens very quickly when someone is unable to train for whatever reason. It is extremely important to keep this in mind when returning to aerobic exercise because you are much more likely to injure yourself if you try to jump right back into the same exercise level you were at previously. This is because your body is not adapted to perform at the same level anymore.
Tapering
This is a gradual decrease in exercise load including duration, frequency, and intensity leading up to an event. If you are training for a big run, you want to make sure your body is in the best condition possible for performance. Reducing the load on the body while maintaining your fitness is the goal of a taper. Tapering is usually 1-2 weeks before an event.
Resistance Training
Just like high intensity runs are important for muscle recruitment and strengthening of muscles (even for ultra endurance athletes), resistance training is important for strengthening and injury prevention for all endurance athletes. Performing a lot of cardio has been shown to impact the development of anaerobic strength and power, however resistance training does not harm aerobic capacity.
Resistance training can help improve running economy as muscles are more efficient through strength gains made with anaerobic training. It also helps muscles tolerate increased impact as training programs are progressed! It’s important to remember not to overload the muscles with resistance training as too much can also increase injury risk while the muscles are recovering. This is why physical therapists often analyze movement and help strengthen specific areas of the body via exercise prescription. Again, this helps the body better tolerate activity for reduced injury risk and improved recovery from injury.
Conclusion
How do you usually approach aerobic exercise and how can you use the above ideas to improve that approach? Have you been forgetting any of the types of endurance training? I’m happy to discuss and look forward to any questions you may have! Stay well!