Everything You Ever Wanted To Know About Energy Zones !!!

Seasonal Design is based on stressing the body in various ways over time in a manner that prepares it for peak performance at the end of the season. In order to do this effectively, one needs to know what energy systems are used to fuel the body and how much, and when, to stress them to achieve the best results. Before you can talk about season design, you need to understand the energy systems, how they work and how to stress them within the context of a swim training session.

This article’s goal is to fully explain the five energy zone systems we use for seasonal design. It is my hope that it will give you a real insight into the specific purpose of each zone and how we create sets to target them. I will post the scientific version of each in the descriptions as well as a real world version as well. Parents, it might be good for you to read this as well so we are all on the same page moving forward. 

Grab your beverage of choice and three, two, one ... GO !!!

ENERGY ZONE DESCRIPTIONS

• Ib 
• Scientific Version - Aerobic (Lipid Exchange Level)

Oxygen intake level is less than 50% from maximal. Lactate concentration in blood around 0.6 – 2 mmol/L

• Real World Version - “Long & Strong”

Your heart rate will be low (12-13 depending on the athlete, their training level, etc). Sets designed here should be an hour or longer of work. Generally, you want longer sets with shorter rest. This does not have to be non stop, but if there is too much rest, you will not get the adaptation you want here. Using the advice above, you are better off with timed sets such as a 400 IM with 15 seconds rest followed by 8 x 75s (2 of each stroke) with 15 - 20 seconds rest. You could add a kick set as well. The point here is that the total amount of work is over one hour. Be creative, just remember not to take too much rest and keep the total work at least one hour...and remember the total time of the set will be over an hour due to rest so keep that in mind when designing yours. Sixty minutes plus of work.

• Ia
• Scientific Version - Aerobic Sub-zone of initial acidose.

Oxygen intake level is 50-60% to maximal. Lactate concentration in Blood 2-4 mmol/L.

• Real World Version - “Hard, But Makeable”

Your heart rate will be slightly elevated to around 140 (+/- D.O.E.) These sets should be thirty to sixty minutes of work. Again, varying them is the key while using short rest. Nonstop T30 swims are also good to use in this energy zone, but the swimmers will not enjoy that over time (some may). Any combination of kicks, pulls or swims work well here. 32 x 100s holding1:00 with 15 seconds rest free (depending on your goal times of course) then alternate stroke on an appropriate work:rest ratio is a good sample set. Another good strategy is starting with thirty two sendoffs and adding a couple per week. This is especially helpful if you do the same set on the same day of the week (parametrics). Keeping everything the same and adjusting one parameter (in this case reps) is a great way for the body to adapt to stimuli.More on Parametrics in another article.

• II
• Scientific Version - Quasi aerobic

Level of Oxygen Demand (RO2 ) is less than maximal oxygen consumption (VO2 max ), however is higher than working distance consumption, which may reach 70-80% to maximal. Lactate concentration in Blood > 4 mmol/L

• Real World Version - “Uncomfortable”

Your heart rate will be 150-160 (+/- D.O.E.) These sets should contain between fifteen and thirty minutes in length. These are hard sets. We still do not want a lot of rest in these sets, but you could start off the season with a little more and tighten it up as you progress. 32 x 50 on 45 seconds alternating 2 x free, 2 x no free is a good example of a set in this zone. You could start out with 20 seconds rest the first week and tighten to 10 seconds by week three.

• IIIb
• Scientific Version - Mixed Aerobic-Anaerobic

Sub-zone of aerobic toleration. Oxygen Consumption level –90-95% to its maximum, Oxygen Debt 60-65% to its maximum values

• Real World Version - As Fast As You Can HOLD aka "AFAYCH”

Your heart rate will be 170 - 180 (+/- D.O.E.), Your sets will be seven to fifteen minutes of hard work. These sets are kind of like holding the back end of your two hundred time. To hold your 200 time, even the back end, for fifteen minutes is Herculean to say the least. Swims that mimic combinations of 25s, 50s, 75s and 100s would work well here. For example, swimming the following set 12 times would be a good zone IIIb set: 1 x 25 on :20 1 x 50 on 40 1 x 25 on 30 to total the time threshold in the zone is a good way to offer swimmers a set in this zone (gain, times and hold times are individualized)  Again the possibilities are endless. The trick here is to stay in zone. If you are under the effort level, you really dont have much of a set as it doesn’t meet the time limits of a lower zone or the effort level of this one. Hopefully, you are starting to see how this all works.

• IIIa
• Scientific Version - Mixed Aerobic-Anaerobic

Sub-zone of maximal Oxygen Consumption. Oxygen debt 70-80% to its maximum values.

• Real World Version - “AFAYCH”

Zones IIIa & IIIb are the real secret sauce to being in shape. The difference, just like in every other energy zone except for Zone II (no sub-zone) is duration and intensity. The “a” versions are shorter and higher intensity than the “b” version of the same energy zone. In this case, think front end 200 speed. For IIIa, sets are three to seven minutes of actual work. Total set time, obviously, will be longer. Sets such as 12 x 50 holding 30 seconds swim on 45 seconds  AFAYCH, for example, work well (your times and sendoffs will vary based on your goal times). Again, you can start at the lower end of the time limits for the sets and work up gradually over time. Zone III sets, a or b, begin in the middle of the season after we have built up our bodies to a point where they can sustain them. If they are overused, especially too early in the season, it can lead to plateaus, injuries and failed seasons. These sets should be introduced after a month or so of steady training. More on that in another post. 

• IVb
• Scientific Version - Glycolytic – Anaerobic

Sub-zone of lactate toleration. Time of all-out one time exercise effort – 100-180 seconds.

• Real World Version - “ As Fast As You Can Go!”

These are all out efforts. In the real world, we are not as concerned with heart rate as we are with speed. Since these are fast swims, it would be better to focus on stroke rate or tempo. Knowing your tempo for different races can be helpful. Using a stopwatch while you are watching a recording of your races (especially tapered) is a good way to find your stroke rate (one complete swim cycle). Pairing that information up with a tempo trainer is even better. Sets should be designed to have bouts last between forty and one hundred seconds of work.  2 - 4 x 50s on 2:30  is a good example of a zone IVb set. You could also cut the time in half and double the reps. Again, kick, pull, swim or any combination can be used. Resist the temptation to do a recovery swim between rest here (unless you are new to this strategy). This strategy will help the body better learn how to deal with the byproduct of work. These sets come later in the season when we begin to realize the gains we have made to date.

• IVa
• Scientific Version - Glycolytic – Anaerobic

Sub-zone of maximal Glycolytic Power. Oxygen debt and concentration of lactate blood are reaching its maximum values.

• Real World Version - “As Fast As You Can Go”

The focus is on speed and power while holding technique. These sets come later in the season, like IVb. They are powerful when used by someone who has built up to this all season long. Like zone III. zone IV can place major demands on a human body and must be used appropriately and by athletes’ whose bodies are ready for it. Sets here are comprised of forty to one hundred seconds in total work time. 2 - 5 x 20 seconds ALL OUT with 4 minutes rest works well here.

• Vb
• Scientific Version - Glycolytic 
• Real World Version - As Fast As You Can Go”

Once you get to zone IV and above, it’s all about holding the fastest speed you can over an ever decreasing duration. In this zone we are talking about twelve to forty seconds of work 2 - 4 x 10 seconds all out with 3 - 4 minutes rest is a good example of how to create a set in this zone. In the real world, the non tethered world, you would also be gauging dive entry, underwaters, breakout distance & speed. For this post, it’s all about tempo.

• Va
• Scientific Version - Alactic (Creatin-phosphate)
• Real World Version - All Out 15s - 25s

Sets such as “Tombstone to Streamline” flag to flag Hypoxic kicking come to mind when I think of this zone. 8 to 12 x 25s ALL OUT on 1:15 would be a real world example for this zone. To mimic that 8 - 12 x 10 to 12 seconds ALL OUT on 1:30 would be a good replacement. Keep it real. Everything in these higher zones should be as fast as possible to maximize your gains. 

I know, There is a lot to process.

I like to think of each energy system as a tool. Each one does a specific job. If you only have a hammer, every problem looks like a nail. Too many times, coaches think in three gears, Smooth, medium and all out. Don’t get me wrong. There is no one right way. People have been successful using their own systems. For me, I am gambling adverse. I like to know the outcome before it happens. 

I have been using this system for over twenty years with much success. The best athletes I have worked with all knew the pacing and feel of each individual energy system down to the tenth of a second

One last thing. I love design seasons, but I love designing developmental paths even more. It’s rewarding to invest sixteen weeks with a group of athletes and see great results. It is even more rewarding taking ten or more years with a person and help give them developmentally appropriate seasons that culminate in a fantastic career.  The swimmers and their families become my family over that time frame; hence why I coined the term “Swamily” many, many years ago. 

If you have any questions, just let me know. I love helping swimmers and their families understand why we do what we do...it makes the process so much better.

See you at the pool - Rich