Building a training program part 3

        In part one of this series, we discussed the importance of a needs analysis in building a training program. In part two, we discussed exercise selection. Now, we will look at training frequency. Training frequency alludes to the number of times you train per week. Offhand look at your foundation of training, are you a beginner, intermediate or experienced in training. For full disclosure beginners have six months or less of training, intermediate is generally considered six to twelve months of training and advanced have been training for a year plus. This correlates to the number of times that is recommended to train. Beginners train 2-3 times a week, intermediate is 3-4 times a week and advanced is 4-7 times a week. These are general by the book recommendations. More often than not if you're training two to three times per week then total body training would be best while more advanced can incorporate more split training. This can be your "bro" split of chest, back, shoulders, legs, abs or back and biceps then chest and triceps then legs and shoulders. The only limit to splits is your imagination. Time of year factors into your decision making. Let's say you're playing a sport that is conducted in the winter. The summertime would be your off-season meaning increased training sessions the fall would be your "Pre-season" with slightly less training then during your "in-season" would entail one to three sessions during the week then the springtime would constitute your "post-season." which entails rest, recovery and rehabbing injuries. One aspect that is overlooked is deep diving the intensity of the workouts and building rest periods off those days. If Monday is an intense day, then Tuesday would be a lighter day to prevent CNS fatigue. 

    

             

Building a training program part two.

     In part one of this series, we explore the importance of a needs analysis when building a training plan. Even if you're not an athlete or participating in a sport a need analysis can be conducted to towards military training or physical events such as Spartan Races, 5K's, Tough Mudders. I'm a big advocate for physical events because 1) it gives you a goal to shoot for and 2) it ensures your accountable for your physical fitness. I consistently have to have physical goals to keep me on track. Being in the Army we have our physical tests twice a year; between those events I run in 5K's, participate in foot marches, or play a sport for fun. My worst progresses fitness wise is the month after the A.C.F.T for I don't have goal. Ok rant over back to the how to guide for building a plan.

    After the needs analysis the next step is picking your exercises. Now, many components can go into building a plan such as agility, change of direction, speed and plyometrics. For this post I'll focus more on the resistance training aspect. Lifts are generally broken down into four categories: 1. Core (which the word itself typically means abdominal training. In this case it means your core exercises that you're building your plan off. These are your presses, pulls, squats, hinges carry, etc. Basic movements that encompass multi-joint compound movements. 2. Acessories. Acessories are your isolation movements such as bicep curls, triceps curls, calve raises. Exercises that recruit smaller muscles. 3. Structural exercises load the spine either directly (squat, deadlift) or indirectly (power cleans, jerks). Any exercise that involves the stabilization of the of posture. 4. Power. Power exercises are performed quickly and are more often than not more sport specific.

    Selecting exercises within a training plan starts with an asterisk. If you're playing a sport, then your sport dictates which exercises to do. Basketball, football, baseball players utilize fast twitch muscle fibers thus training will be based around Olympic style lifts. Track and field athletes that participate in the 800m will be based around lunges, single leg deadlift (any exercise that is the locomotion of running). If you're not involved in a sport, then stay with the basic movements of push/pull/squats. Muscle balance is another key element that again has an asterisk. Hearing muscle balance typically refers to agonist (prime mover) and antagonist (muscle group located on the opposite side) think bicep and triceps. Instead of that balance think more of muscle ratio. Take the leg muscles for example. The quadricep has four muscles while the hamstring has two. So, the ratio would be 2:1 quad to hamstring exercises. Another factor is a recovery element placed somewhere in the training plan. Training intensely over and over may cause Central Nervous System (CNS) fatigue. Low intensity aerobic exercises balance the high intensity to maintain equilibrium. Additionally, low intensity would help remove metabolic wastes caused by high intensity exercise. Experience with technique plays a factor as well. An experienced lifter can perform higher amounts of Olympic lifts than an inexperienced lifter. Lastly, time allocated to weight room and availability of equipment are two aspects to consider. Some gyms do not have sleds (or an area to perform sled pushes and pulls). How much time do you have to lift? 45 min is vastly different then 90 min. 45 min would include more complex training and supersets to ensure the routine is covered while longer duration can include longer rest times with a focus on one lift at a time.       

Why a Needs Analysis is important for training.

       One of the first things you should do before training is to have a goal or more specifically a plan to obtain that goal. Note that I said training not working out. Training implies more of a focused approach in the gym and not a collection of exercises.... looking at you CrossFit. Most folks that have experience (for full disclosure a beginner is typically two months into training, intermediate is two to six months in and advanced are a year plus) in the weight room often play a sport on the side to supplement training or an event such as a Spartan Race. 

    In order to play that sport effectively training should reflect the metabolic demands of that sport. In the fitness world we called this the S.A.I.D principle. S.A.I.D. stands for Specific Adaptation to Imposed Demands. In 5th grade terms SAID implies the end result of your training period reflects your goal. Want to get bigger and stronger? then lift heavy weight. That is an oversimplification of the concept, but you get the idea. Football players do not continuously run for miles at a time during play, so why have them do two mile runs during training?

     In more practical terms think about basketball-lots of change of direction and jumping. Training is going to include plyometrics , sprinting, resistance training and change of direction drills. On a side note, change of direction is changing direction without knowing the predisposed destination. Typically, these drills include a mental stimulus that indicates where and how to change direction. Destination would include a coach pointing left or right as you approach the predetermined route. The how is how deep is that cut. Is it a 45-degree cut, 90 degrees or 180 degrees? Direction of cut requires different muscles and speed involved in the cut. A shallow cut can be performed rather quickly, while a 180-degree cut requires the body to slow down to a degree. Additionally, the legs have to be strong enough or quick enough to stop and push off with enough force as to not lose speed. For a full circled conversation plyometrics help with all of those details. See how detailed one aspect of training can get? Basketball is full of change of direction either playing offensively or defensively. Jumping can also be broken down into smaller details as well. Basketball rarely has a player conduct a running jump. Standing jumps and one-legged jumps would be better suited. Additionally, jumping in basketball requires hands to be up (think a block on the defensive side). Countermovement jumps that include arms up to the highest peak reached is more equivalent to the sport. Pogo jumps are another option since rarely a player has enough time to perform a complete countermovement jump within play. Strength training should also reflect the sport. Basketball is played upright, so lifts should be conducted upright. Exercises such as standing shoulder press, back/front squat should be used. Position also matters. In our basketball example a front court player would need to be "shiftier" than a backcourt player, so more change of direction drills is necessary. Back court players need to be a little thicker than front court players to have the strength to battle for rebounds and be physical in the paint.

    After considering sport and position movements. Testing can be conducted to see where you can improve to be better at that sport. Putting together a plan should follow these principles and these  In addition to resistance training basketball skills should be implemented to improve overall game play.

Banned substance's part three

    In previous installments of banned substances series, we have touched on Steroids and HGH. I covered the similarities and differences between both drugs that are more geared towards resistance training. Now, I'll flip the script and go with a drug that can enhance aerobic training: Blood doping or more specifically Erythropoietin or EPO for short. Much like steroids and HGH EPO does have medical benefits, however since this blog more focuses on athletic performance, we will look at that perspective. 

    Blood doping is artificially raising red blood cell production. Red blood cells carry a protein called hemoglobin that carries oxygen to working muscles. Having more oxygen increases the ability to exercise aerobically for longer and at higher intensity. It can be accomplished by blood transfusions and drugs. Blood transfusions can either be conducted autogous or homologous. Autogous is using your own blood to extract the red blood cells then inserting them back into your body. Homologous is using another person's blood (have to be same blood type) extracting the red blood cells then inserting them back in your body. EPO is the drug that stimulates red blood cells in the body. EPO is a naturally occurring element within the kidneys that does produce more red blood cells. Abusing the drug does indeed work (hence why athletes use the drug.... looking at your Lance Armstrong) It has been reported that through six weeks of treatment that aerobic capacity increased by 6%-8% and time to exhaustion increased by 17%. Some of the downfalls of taking EPO (besides that it is illegal) is that once EPO is injected the user cannot control red blood cell production which may cause the blood to thicken which in turn causes elevation in blood clotting, systolic blood pressure and in extreme cases stroke or death.

    

    To naturally increase red blood cell, count living or exercising in high altitude does the same thing. Elevation at 3900 feet causes immediate and long-term adaptations. The reduction of partial pressure of oxygen causes the body to work harder to perform the same exercise. Acute responses are increased cardiac output, increased heart rate. Longer or chronic adaptations through acclimatation (roughly 10-14 days) lead to lowered maximal heart rate, lowered cardiac output and decreased stroke volume. More red bloods cells are produced, capillary density of muscles is increased, and the mitochondria (key for Krebs cycle) are all increased. A rule of thumb for altitude is to "live high train low" meaning it is better to live at high altitude then train and lower levels of elevation so to train at higher intensities.         

Basic Understanding of Human Growth Hormone (HGH)

     In our current series of anabolic hormones, we deep dived testosterone and Steroids to complete our series we look into Human Growth Hormone. Often times we correlate HGH with Steroids and in a sense, they do the same thing. Both stimulate skeletal muscle growth and are quite effective when coupled with resistance training. Furthermore, both are naturally occurring elements within the body. Steroids are derived from sex hormones in males and females. HGH is secreted in the pituitary gland. Both are used medically, however since my specialty is in exercise, we will be deep diving that aspect. Much like Steroids, HGH is injected into larger muscle areas (on the other hand Steroids can be taken orally while HGH is not effective taken orally). HGH is also a banned substance when taken for athletic performance.

     Generally speaking, HGH differs from Steroids in that HGH stimulates bone growth and maintains blood glucose levels and increases the uptake blood glucose and amino acids.  Additional blood glucose and amino acids would stimulate protein synthesis naturally. Another significant difference is that HGH in terms of athletic performance is not studied to the degree of Steroids due to the ethical concerns. Intentionally giving an athlete HGH would not only grow muscle tissue, but bones as well which may lead to acromegaly (disfigure widening of bones, organs and metabolic abnormalities). Words only do this justice; pictures are more effective way to convey just how large a human can get. Below is a picture of former baseball player Barry Bonds. To the left is Bonds early in his career with the Pirates and the right is Bonds later in his career with the Giants. Bonds went from an all-around player that could run, steal bases to a slugger who completely stopped stealing bases.  

Testing for HGH is only found in blood tests. Urine tests are not effective in identifying HGH.
     

General understanding of Steroids

      If you have read my last post about testosterone then you know that I foreshadowed a deep dive into Steroids....to paraphrase Ben Affleck's Batman, "Well....here I am." For article's sake I'll be looking at the performance aspect of Steroids. There is a medical aspect, but your here to read about the performance side of "juicing" instead of the medical side.

     When referring to steroids within the context of this post then I am referring towards Anabolic Steroids. Anabolic is in this context is a discussion about the cellular "buildup" process. Steroids are man-made synthetic derivatives of the male sex hormone. In the 1930's the effects of Steroids were tested. Exercises scientist soon found out that steroids in itself is a very poor ergogenic aid. In order to make it effective chemical modifications had to be made. During the 1940's and 1960's German chemist created what the world now knows as Anabolic Steroids. At first, Steroids served as an aid to German Soldiers to increase aggression. (Which in a way....it was a success. Increased aggressive behavior is an indication of Steroid abuse (Roid rage anyone?). The perfect example would be the Rafel Palmeiro testimony during the height of the Steroid era in baseball pointing his finger and emphatically saying, "I have never used Steroids....period." For full circle of conversation Palmeiro did in fact take Steroids during his career. 

    For full disclosure-Steroids do work. Steroids increase testosterone levels by 2 to 3 folds higher. By increasing testorone levels the body. Coupled with resistance training it Stimulates protein synthesis which increase muscle mass, strength and body mass. Bottom line if you want to get bigger and stronger lift weights and take Steroids. Generally, speaking Steroid uses "stack." various types of Steroids either by orally taking them or injecting them in large muscle areas i.e. the buttocks. On average users stack at least 3 agents in 5–10-week cycles. Steroid users typically fall into two categories: performance enhancing and body dysmorphia. Performance enhancement would be your athletes trying to get bigger, stronger and faster. History has several examples of athletes uses drugs to get better. Just google baseball players or Olympic athletes taking drugs to enhance performance. Body dysmorphia is the belief that big guys are internally viewed as small.

    Negative aspects of Steroids are increased aggression (touched on that earlier). Acne, smaller testes (which lead to decreased sperm count and slowed natural production of testorone). To stimulate testosterone production naturally some users, take Human Chorionic Gonadotropin or HCG for short. HCG is derived from the placenta of pregnant women. After roughly four days of administration of HCG then testosterone levels can nearly double.

The most obvious negative aspect of Steroids is that it is illegal. Do not take them.                  

Everything you want to know about Testosterone

    If you have been in the gym more than a week then I have no doubt that you have heard some gym bro talking about testosterone. Testosterone is one of three primary anabolic (building process) hormones in the body along with growth hormone (same growth hormone that baseball players were taking back in the late 90's early 00's. Growth hormone comes naturally within the body as grows everything. Baseball players abused this drug hence why Barry Bonds head looks like a pumpkin) and IGF's. Growth hormone and IGF's will be discussed in later posts. Today's focus will be on testosterone.

    Hormones are secreted before, during and after resistance exercise through a theory called lock and key. Hormones would be the key and receptors would be the lock. Just like in a real example of locks and keys; a certain key fits a certain lock. The anticipation of resistance training alone releases a hormonal response. In terms of during and after exercise would depend on the flavor of training. Since this article is more based on resistance training, we will deep dive that aspect. Since hormones are released to maintain homeostasis throughout the body training using our resistance training model the objective would be to release certain hormones in order to repair and build muscle tissue. For full discloser, aerobic training tends to have a catabolic (tear down) effect then different effects are implemented on the body. Predominate aerobic exercises may require some resistance training to supplement the catabolic process.        

     Testosterone is mainly a male sex hormone derived from the testes. I say mainly male because females have testosterone in their sex organs, however it not mass produced as in males. To go on a quick tangent if you're a female and you do not lift heavy weights for fear that it will make you "bulky" is simply not true. You will build muscle with heavy resistance training (and good nutrition) but not to the degree that males will be due to testosterone factors. Women have 15-20-fold lower testosterone than men. Generally speaking, testosterone levels are the highest in the morning with the added asterisk that exercise will change these levels throughout the day. The book definition of testosterone is the primary hormone that interacts with muscle tissue and is the key component to stimulating anabolic functions. In more laymen's terms it helps build muscle. Testosterone helps build muscle directly and indirectly. Directly in the sense that it can promote growth hormone from the pituitary glands and indirectly by increasing the number of neurotransmitters and influence structural protein changes.

    

    Increases testosterone naturally occurs during heavy resistance training (85%-95% of 1RM) with large muscle groups (ie compound movements such as squats, bench, deadlift, power cleans) with multiple sets. One set of heavy squats does elevate testosterone levels but not to the degree that multiple sets do. Two or more years' experience in the weight room play a factor as well. Along with multiple sets and heavy weight short rest periods such as 30 seconds to 1 minute maximize testosterone levels. The rest periods may be counterproductive since lifting 90% of 1RM for multiple sets requires longer rest periods. The unnatural way of course is to take anabolic steroids. To lightly touch on steroids (deep dive coming.... we call that foreshadowing in the writing world). Anabolic steroids are a synthetic version of testosterone that unnaturally increases protein synthesis causing improvements in muscle size, body mass and strength.       

How to warm up effectively

    I am 100% guilty of not dedicating enough time for a warm-up. 9/10 I am in the gym early in the morning and have to hit timelines in order to start the day. I breeze over one of the more important aspects of training: The warmup. My "send it" philosophy comes back to bit me. Warming up prepares you physically and mentally for training and has been shown to improvement performance. Faster muscle contractions, rate of force development, reaction time, improvements in strength and power, increased oxygen (through the Bohr effect) and increased psychological preparedness are some of the positive effects of warming up. Negative aspects of warming up are_______. Yep, that's right. No negative effects exist from warming up. The physical side of warming up are fairly obvious-get the body moving, get the joints limber then attack the training. Mentally, Training generally at the same time elicits an adaptation from the autonomic nervous system to prepare for training. This is why many fitness enthusiasts speaking very highly of being consistent with training. It is not just the consistency of working out it is the consistency of mentally preparing yourself. Generally, speaking this oversimplification of get the body moving can be broken down into temperature and non-temperature related improvements. Temperature correlates to muscle temperature, core temperature, enhanced neural function. Non-Temperature is more associated with increased blood flow, elevation of oxygen consumption and post activation potentiation. These benefits are elicited from actively warming up. Yes, sitting in your car passively with the seat warmers on will warm up your muscles and core temperature but you're not getting the whole benefit. Its equivalent to eating a doughnut for breakfast-yea you had breakfast and its calories, but it does have severe limitations.

       The actual warm up typically consists of two phases: General and Specific. General warm up of slow aerobic activity lasts for approximately five minutes. General warm-ups fit into any activity. Walking/jogging, biking, elliptical are all good examples of a general warm up. The goal is to progressively warm up the body for exercise. More often than not light stretching is incorporated into the general warm up (after the initial five minutes of warming up). One note about stretching (especially static stretching) is that it is a mixed bag of research pertaining towards force production activities such as sprinting/jumping and reaction/movement time activities. If you're going to static stretch conduct it after completing those activities. Imagine taking a rubber band and stretching it out then attempting to shoot it as far as you can. That is what you are doing to your muscles statically stretching before force production activates.

    Specific warm is specific to that workout. For example, let's say I am benching. First, I would warm up with really light weight then gradually ease into more weight. The goal is to fulfil the R.A.M.P. protocol. R=Raise meaning to raise the level of temperature of the body and increase skill level. In our benching example start with a machine then progress into barbell benching. A=activate and M=Mobilize entails movement patterns and includes more dynamic movement that reflect upcoming training. Full and complete range of motion are key here. Dynamic movements involve multi-joints and can be time efficient. P=Potentiation. Potentiation refers more to skillful movements that typically involve activates that pertain towards sports specific activities. If I am about to play basketball, then potentiation would include layups using generic moves and speed then progressing into game like movements and sharp cutting.   

    Two key aspects about warming up is that after warming up you have approximately 15 min to conduct your activity. Anything over 15 min you start to lose the effects of warming up. Another is to differentiate between warming up for training which may entail short-, medium- and long-term planning to get overall develpment and competition warm up that acutely gets you ready for competition.      

How to apply plyometrics in training

     In part one of this plyometrics we went over the nerdy fitness knowledge of the exercise. In part two we will discuss how to apply this knowledge into training. Before getting into the meat portion of the article please know that plyometrics are designed to increase power, not an aerobic exercise. Multiple boxes jump with minimal rest creates a more aerobic exercise. 

    Any training program starts with a needs analysis. Plyometrics are no different. Consider your training history. Are you experienced in the weight room? are you a beginner? How much mass do you have? These factors play a significant role in designing a program. It is recommended that beginner stay in the 80-100 rep range (this is typically measured in individual foot touches, although throws and upper body plyometrics can be included). Intermediate (roughly between 6-12 months experience) has a rep range of 100-120. Advanced is typically from 120-140 touches. Keep in mind these are maximum effort exercises which place high stress on tendons, joints and muscles. Mass plays into more advanced plyometrics such as depth jumps. Depth jumps are when you stand on a box, step down then jump again. Box height of 30-32 inches is recommended. This is due to the increased stress on the tendons thus creating more amortization phase and defeated the purpose of the exercise. After four weeks of consistent plyometric training should lead to increased results.

    After figuring out your training status and rep ranges. Will upper body, lower body or truck exercises be implemented? Lower body plyometrics are more common with box jumps, hops and skips being the more typical exercises. Throws, catches and plyometric pushups are examples of upper body exercises. In part one I foreshadowed truck plyometrics. Truck plyometrics are difficult to perform since the stretch reflex may not be used throughout the exercise. The decreased movement pattern creates plyometric like movements just not true plyometrics.   

    Beginning a plyometric program is similar to starting a resistance training program. Start off small and use the progressive overload principle. Double leg hops, squat jumps and small box jumps are examples of exercises that have a low intensity while single leg hops or jumps are more progressive. Multiple jumps that are incorporated, changing directions or depth jumps are more advanced exercises. Time between exercises is a key component to ensure enough rest to fully maximize the potential of the exercise. A Work/Rest (W: R) of 1:5 to 1:10 is recommended. This means that jumps that take 10 seconds then your rest range is 50 seconds to 100 seconds.

    Landing surface is the last factor in applying plyometric exercises. A good surface has to possess adequate shock absorbing properties. Too rough of landing creates too much stress; too soft of surfaces (trampolines or thick exercise mats for example) create too long of amortization phase thus defeated the purpose Grass, suspended floor or a rubber mat are all good examples of ideal landing surface. A box should have some sort of grip surface to ensure slipping is not a concern. Many boxes either have non-slip properties or sand mixed in the paint to create a grip like surface. Slipping off a box that is 30 inches off the floor is bad news.

    The best way to implement plyometrics is to incorporate them into an overall program. For resistance training put the plyometrics first. This strategy is used to ensure the body is fresh and can be max effort into each movement.     

The most underrated beneficial exercise you're not doing.

    The most underrated, beneficial exercise that you're not doing is Plyometrics. Fitness nerdy definition of plyometrics is a quick, powerful movement using a pre-stretch or countermovement that involves the Stretch Shortening Cycle (SSC). A more practical definition is to produce maximum force in minimal time. The goal of this exercise is to produce power either through upper body or lower body exercises. Notice I did not say abdominal exercise. I'll get to that later after defining what happens in the body during this particular exercise. In fancy writers' terms we call this foreshadowing 

    Two aspects incorporate plyometrics The mechanical model and the Neurophysiological model. Mechanical model encompasses a rapid stretch immediately followed by concentric muscle action. Imagine compressing a spring then releasing said spring. Series elastic component (SEC) of a tendon is the compressing of the spring. Compressing that spring or SEC creates stored energy then releasing that spring or the contraction of a tendon causes a powerful result. Now, if that spring is slowly released the result is not as powerful. Same action applies to the mechanical model. Quickly squatting down then holding that position then jumping is not as effective as quickly as quick concentric action immediately followed by an eccentric phase. The delay in fitness terms is called amortization. Spending too much time in the amortization phase causing the concentric phase to not be as powerful since the stored energy dissipates and is lost as heat. Since the beginning action causes a stretch free of energy (free meaning it does not cost any ATP) energy is stored then used in the concentric movement. 

    Neurophysiological model is a bit more complicated. It involves a process called potentiation. Potentiation is the change in force velocity characteristics of a muscle's contractile components by a stretch. Throwing your arms down violently while performing a countermovement jump changes the force applied to the jump. To apply this in training perform a set of squats followed by a countermovement jump the leg muscles are trained to perform quicker and more powerful. This style of training is called complex training and is typically reserved for more advanced personal. During plyometrics the muscle spindles (proprioceptive or sensory organs that are sensitive to rate and magnitude of a stretch) are stimulated by rapid stretch causing reflexive muscle action which causes potentiation hence increasing the force of applied muscle.      

How to use the energy systems for training.

    You know what is cool and unique about the human body? Now matter how you exercise the body has a response for it. The heart, the lungs, the mind, etc vary in response to exercise. The Fuel system works the same way. No oxygen for fuel? Bet, we will use carbs. We out of carbs? No problem. We can throw fat and protein at the problem. We got oxygen. Cool now we can make more ATP. It is the epitome of the video of Jocko saying "Good" over and over.

 How does the body do this? Much like everything about the human body. It depends on what you're doing and how long you're doing it. In other words, it depends on Intensity and duration. 

    Short, quick, high intensity exercises such as sprinting, resistance training and plyometrics utilize a bioenergetics system called the Phosphagen system. The Phosphagen system provides ATP for roughly 5-10 seconds of work. The energy is derived from the hydrolysis of ATP and the breakdown of another high energy molecule called creatine phosphate (CP) or also known as phosphocreatine (PCr). If creatine sound familiar it is in fact the ergogenic aid creatine. If I may go on a tangent for a few sentences, creatine is the most widely studied supplement on the market and is totally safe to take. It should assist with increasing performance through the phosphagen system (as long as it is trained). Taking creatine and training aerobically has minimal effects. The body stores more creatine than ATP, however it burns quickly and is slower to replenish than ATP. In fact, the body stores roughly 80g to 100g of ATP at any given time while the body hold four to six times more creatine. Since the intent of the phosphagen system is short, quick, powerful bursts it takes time to recuperate the ATP and creatine usage. Ideally, you would want a 1:12 to 1:20 work rest ratio. Meaning that if I conduct broad jumps that take roughly 5 seconds then I would wait at least 60 seconds before my next set (5x12) or 1 min and 40 seconds (5x20). This is done because after a single bout 50%-60% of ATP is lost.

    Fast Glycolysis (FG) is another biological energy system that typically lasts 15-30 seconds per bout. Since FG lasts a bit longer than the phosphagen system another process is utilized. That process is called the Cori cycle. In order to replenish the FG system a work/rest cycle would be 1:3 to 1:5. A 30 second sprint for example would require 2 and a half minutes of rest (30x5). 

    Slow Glycolysis (SG)/oxidative starts off the same way as the Cori cycle with the exception of the direction of pyruvate. Instead of sarcoplasm (which then turns into lactate which turns back into glycogen. Think of a turbo in a car). SG utilizes the mitochondria and oxygen within a cell to form ATP. This is a longer process (costs two ATP) but yields larger amounts of ATP. In total the Krebs cycle produces 40 ATP. Since it takes 2 ATP for the Krebs cycle the net yield is 38 ATP. Typically, training the SG/oxidative system lands in the 1-3 min periods with work to rest ratios of 1:3-1:4. An example is a 400m run. Let's say it takes 2 minutes to cover 400m; a proper rest ratio would fall between 6 to 8 minutes. Now, the intensity of this training is much less then maxed out effort of the phosphagen system hence the shorter rest periods.

    Utilizing the oxidative system also uses the Krebs cycle with the addition of oxidation of carbohydrates, fat and in a pinch protein. Carbs are your best source of energy yielding macros as the body can readily use them instead of breaking down fats and proteins first then using the end result for the Krebs cycle. Any training over 3 min uses the oxidation process. The recommended work to rest ratios for this type of training is 1:1 to 1:3. For example, mile repeats conducted at 8 min mile pace requires a range of 8 min to 24 min. 

     During exercise not one energy system is used. It blends a variety of systems in order to ensure the body has enough fuel to sustain exercise. Intensity and duration dictate how much of each system is used. These systems can also be trained to be better. Training reflects increases in a particular energy system. Think about it. If I want to get better at a two-mile run, then I should train the Oxidative system into order to get better at a longer distance. Inversely, if I am attempting to get better at the 100m sprint then I should train the phosphagen system more.