Everything You Ever Wanted To Know About Energy Zones & Swimming At Home

I Have A Home Pool. What Can I Do To Stay In Shape? 

I have heard that alot lately. I thought I would take the opportunity to answer that question while also fully explaining the five energy zone system we use for seasonal design. So even if you do not have a home pool, please read this post. It will give you a real insight into the specific purpose of each zone and how to 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. 

Please forgive the formatting craziness. Team Unify has some, ehem, special features.

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

Not all of us have access to a home pool. Even those who do are faced with the challenge of a smaller footprint than is needed for a breakout, let alone a good swim workout. How can you maximize your resource? Below are two products you can purchase to take advantage of your situation. There is no affiliate link or any kickback for me or the club. I just wanted you to have some real world thoughts and feedback on these products

  1. Get A Super Swim ( ) These devices are great. There are many ways to secure them and they are quite effective.The belt is comfortable and the height and angle of the pole makes for realistic swimming. I had one of these for my personal use at my home pool for years. The downside is the cost. The Super Swim runs around $250. Facing the potential length of the shutdown, it might prove to be a good investment. 

  2. Get A Swim Belt ( ) The swim belt comes in around thirty bucks. Obviously that’s way less expensive than the Super Swim. The system works, but it is not as efficient and versatile as a Super Swim. You can adjust the length so there is some ability to make adjustments. It’s a good, low cost alternative, especially for families hit hard by our current situation.

It’s one thing to have the equipment, it’s quite another to know what to do with it. I am not allowed to offer up specific workouts, but there is nothing wrong with me explaining seasonal planning strategies. Armed with that knowledge, you can choose what is best for your family.

As of this post, we are at the beginning of the season. We are targeting the accumulation of an aerobic base as well as strength gains. Both can be accomplished using the tools above. Before I get into specifics, let’s take a step back and review Energy Zones. In a future post, we will explore how they are used in seasonal design.


  • 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

    • R eal 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 devices above, you are better off with timed sets such as 8 x (1 minute of each stroke - nonstop) with 15 - 20 seconds rest after the 4 min “IM”, followed by a set of 8 x (30 kick, 30 seconds pull of each stroke) with 15-20 minutes rest between IMs. Notice 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. Any combination of kicks, pulls or swims work well here. 32 x 1:00 with 15 seconds rest alternate one minute of each stroke is a good sample set. Another good strategy is starting with thirty two and adding a couple per week. This is especially helpful is 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) isa great way for the body to adapt to stimuli.

  • II

    • Scientific Version - Quasi aerobicLevel of Oxygen Demand (RO2 ) is less that 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 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: 15 seconds Free, 5 seconds rest, 30 sec No Free, 10 seconds rest, 15 seconds Free, 15 seconds rest. 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 30 seconds swim, 15 seconds off AFAYCH work well. 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. We are not as concerned with heart rate as we are with speed. Since these are tethered 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 - 3 x 30 seconds all out with 2 minutes rest 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. 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 1:30 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 nearly 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. I hope we will use this downtime to go back to the basics, teach our swimmers and families the hows and whys of the program and return to the pool the better for it.  

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 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.    

All families have issues. Right now, our main issue is shared with the world. We will get through this. We will learn from this. We will get better from this shared experience.  

Thanks for making this far. Next up? Effective seasonal design strategies  

Be safe - Rich