Conditioning

You should always look at the energy systems of the body when designing a proper conditioning program. What are the energy systems of the body? Well, there are three basic energy systems within the human body’s muscle cells, made to replenish adenosine triphosphate (ATP). Think of ATP as the energy source for many of the body’s essential processes. Muscle contraction, muscle growth, nerve impulse propagation, and cellular respiration to name a few.

The 3 Energy Systems

The three energy systems found in the human body are the phosphagen (ATP-PCr) system, the glycolytic system, and the oxidative (aerobic) system. The ATP-PCr system creates ATP primarily for short and high-intensity activities, like resistance training and sprinting. It is highly active at the start of any exercise though, regardless of the type or intensity of the exercise. Because the ATP-PCr system creates ATP for short and high-intensity activities, it is the main producer of ATP for about the first 0-10 seconds of exercise. After the first 0-10 seconds of exercise, the glycolytic system becomes the leading manufacturer of ATP. This system primarily works in the medium length and intensity activities, such as muscular endurance or longer intervals. Because of this, it really comes into play about 30 seconds into exercise and lasts about 2 minutes. After these two energy systems have been exhausted, the oxidative system comes into play. The oxidative system is the most efficient energy system in the body. It just takes the longest to come into play due to the need of oxygen to create ATP, whereas the first two energy systems do not need oxygen to create ATP. The oxidative system dominates in the longer and lower intensity exercises, such as running or even producing ATP at rest. It becomes the main source of ATP about 2 minutes into exercise and lasts from that time onward. All that being said, it is important to note that not just one energy system works at a time. Instead, all energy systems are always contributing to making energy for the essential functions of the body. One energy system just tends to be the highest producer of ATP, depending on where you are in your workout or what the demands of your activity are.

Evaluating Your Needs

Now that you have a better idea of what the energy systems of the body do, and when they kick in, you can look at your own needs and start to see what your own training program might require. If you’re an athlete, your needs may look very different than someone who is not an athlete, because your performance may depend more on a certain energy system than others. It may even look different from one athlete to another. Bottom line is that conditioning should be specific to your needs. For example, if you are an NFL player, the average play lasts for about 4 seconds and the average amount of rest between plays is about 40 seconds. Because of this, it makes most sense to train closest to these numbers, because this is what is needed when it comes to playing. If you’re not an athlete and you do not have specific energetic demands from a sport, your approach may be different. For example, you may be looking more at general health, or longevity, or both. If this is the case, you will want to have a more balanced approach to your conditioning methods. In this case, you will want to include aspects of each energy system. Throughout the course of the week your workouts may contain aspects of all three energy systems. You may include different interval training methods to target the ATP-PCr and glycolytic systems and then you might include zone 2 or long, slow distance cardio to target the oxidative energy system.

INterval Training

As mentioned above, a great way to target the ATP-PCr and glycolytic systems is through interval training. Interval training is simply a type of exercise where you alternate between periods of work (exercise) and rest. The benefits of interval training include increased maximal oxygen consumption (VO2 max) and enhanced anaerobic metabolism. You can do intervals at many different work to rest ratios, but some of my favorites are 10sec:20sec for 8 repetitions and 30sec:30sec for 10 repetitions. In both examples, the first number is the amount of work you are doing, and the second number is the amount of rest you are taking. The first interval option is great for targeting the ATP-PCr system and the second option is great for targeting the glycolytic system. Interval training can be great for other reasons as well though. Training around knee pain being one of them. Many athletes will avoid running due to knee issues or the fear that running will cause their knee(s) to hurt. Often though, long distance running is the cause of this, and interval training can be a good substitution. The idea being that the repetitive foot strikes and impact on the joints can be the cause of pain, and interval training, while also tough, is more difficult on the muscles and mind than on the joints. If doing your intervals through running is still problematic, you can substitute for my favorite way to do intervals, the Assault Airbike. Also known as a fan bike. There are a handful of reasons that it’s at the top of my list. First off, It is “dual-action”, so it more closely mimics the combined arm and leg action found in running. This combination of simultaneous arm and leg movements also produces a higher heart rate than if you were only pedaling. Second, dual-action, fan-based bikes also provide something called accommodating resistance. In simple terms, as you pedal harder, the resistance gets harder. Third, the Assault Bike can help us avoid overuse injuries that can be commonly found in things like running or jogging. As Mike Boyle says, it has minimal orthopedic cost on our bodies. Lastly, dual-action bikes provide the rider with plenty of real-time data. For example, rotations per minute, distance traveled, watts, calories, and time. These give us plenty of ways to track progress and create competition if wanted. One negative with intervals on a bike or when using a method other than running, is that you do not get the full hip range of motion (ROM) from it. This can be a negative if you are an athlete, because if intervals on a bike is your only form of conditioning, you miss out on things like full hip extension, which can be detrimental to your performance and can potentially make you more susceptible to injury.

Get started using intervals

A super easy method to get started with intervals is through the 2-mile time trial. I read about this in Mike Boyle’s book, Designing Strength Training Programs and Facilities, and I have found it to be a great approach to figuring out how to incorporate intervals. You want to incorporate this method first, because the numbers you will get, most importantly your average rotations per minute (RPMs), will be the base for the workouts that follow this test. To get started, hop on an Assault Airbike and ride at a pace that you can consistently maintain for 2-miles without burning out. You should make sure to record the time it takes to reach 2-miles, your average RPMs, your heart rate when you finish, your heart rate after 1 minute, and your heart rate after 2 minutes. A good time to aim for is about 5 minutes to complete the 2-miles. Athletes should aim to be under the 5-minute mark. To complete this test in 5 minutes or under, you will need to be moving between 63-64 RPMs on average. A good 1-minute heart rate recovery is about 25 BPM, and a good 2-minute heart rate recovery is about 50 BPM. That means if your heart rate at the end of 2-miles is 180 BPM, you should be around 155 BPM after 1-minute of rest, and around 130 BPM after 2-minutes of rest. From here we can use different work to rest (work:rest) ratios to target different energy systems. For example, 10:20 to target the ATP-PCr system, and 30:30 to target the glycolytic system. If you choose to use the 10:20 ratio, you should be using 120% of your average RPMs from the 2-mile test. So, if your average RPMs were 65, then your work or sprint periods should be done for 10 seconds at 78 RPMs. For 10:20, each set is 8 repetitions, and plan to do 2-3 sets. If you want to target the glycolytic system, you can use a 30:30 work to rest ratio. To do this, use 110% of your average RPMs from the 2-mile test. One set of 10 repetitions will do the trick for this ratio.

Long, slow distance & zone 2 training

Long, slow distance (LSD) training is probably what most people think of when they think of conditioning or cardio. This type of training is your more traditional, long, slow distance running, riding, or swimming. When we think of targeting the oxidative system, this is what we will use. Benefits derived from this type of training include enhanced cardiovascular and thermoregulatory function, improved mitochondrial energy production and oxidative capacity of skeletal muscle, and increase utilization of fat as a fuel. The NSCA says that LSD training refers to training at intensities around 70% of our maximal oxygen consumption abilities (VO2 max) or 80% of our maximal heart rate. An easy way to get an idea of what your max heart rate is, is 220-age. So, if I am 30 years old, my estimated max heart rate would be 190 BPM and my 80% max heart rate would be 152 BPM. This is not a super accurate way to measure max heart rate, but it will allow you to get somewhat close and get started quickly. We should be training in this range 1-2 times per week for about 30-120 minutes each session, according to the NSCA. LDS training is also referred to as “conversation” exercise, which brings me to zone 2 cardio. A type of conditioning that has become increasingly popular in recent years due to people like Dr. Peter Attia. Zone 2 cardio is defined by Dr. Attia as lactate levels being in the 1.7-1.9mmol range. This can be measured with a lactate meter if we want to be very precise. If this is not a method that you are interested or capable of using though, there is another easier method to make sure we are in zone 2. What you should do, is get started with your cardio and get to a point where you can carry out a conversation for a long period of time. Your pace should be slow enough so that you can carry out a conversation, but if you were going just a touch faster, you wouldn’t be able to keep the conversation going. It will not be as easy as having a conversation while relaxing, and you might be breathing a bit heavy and straining, but you can still maintain this conversation for hours if need. This is a good subjective measurement that puts us around the zone 2 range. LSD and zone 2 cardio both share this “conversation” pace characteristic and are very similar. Except by the NSCA’s definitions, LSD training may be a slightly higher intensity workout than zone 2. Dr. Attia recommends getting about 2 hours of zone 2 cardio per week to start. Split that up how you want, but I would recommend at least 30 minutes each time you do zone 2 cardio. One thing to note is to be careful of doing a lot of low and slow cardio if you are an athlete. You have technically have three types of muscle fibers in the body, but they break down into two categories, slow and fast twitch. If you do high amounts of zone 2 or low and slow cardio, it can convert your muscle fibers to become a higher percentage of slow twitch fibers. This can negatively impact performance if you are an athlete, because athletic performance is highly dependent on fast twitch muscle fibers.

Conclusion

Now that you have a better understanding of the energy systems, analyzing what your performance or life needs are, and how to incorporate different conditioning methods into your routine, you should have a good foundation to move forward with. Look at the three energy systems, figure out what your needs are, and then incorporate intervals, zone 2, or both types of conditioning into your routine. This should give you a very good and simple foundation to target your conditioning. If you have any questions, please don’t hesitate to reach out. I’m always happy to help however I can. My contact information can be found at the bottom of my websites home page.  

References:

Boyle, M. (2023). Designing Strength Training Programs and Facilities (2nd ed., pp. 149-159). On Target Publications.

Haff, G., & Triplett, T. (2016). Essential of Strength Training and Conditioning (4th ed., pp. 567-573). Human Kinetics.

[Peter Attia MD]. (2022, March 29). How to find your “Zone 2” without using a lactate meter [Video]. Youtube. https://www.youtube.com/watch?v=AoB2AMUq8Wg

[Peter Attia MD]. (2020, February 10). Exercising for Longevity: Peter on zone 2 and zone 5 training [Video]. Youtube. https://www.youtube.com/watch?v=Eb92hyaoGrU&t=1s