Cross Fit: Does it really achieve the results it claims? Part III: Does cross fit lessen athletic performance: endurance with strength & power

Article by Mark Wine

Cross fit’s premise is simple, perform as many reps and designated exercises as fast as possible. Performing or viewing a cross fit workout will provide you with the idea that cross fit participants utilize endurance training, which is a correct observation. The emphasis of cross fit is on muscular endurance (buffering hydrogen ions) and an overall cardiovascular output. Athlete’s involved with sports that require a higher VO2 max and/or improved muscle buffering capacity (MBC) show great benefit when performing muscular endurance and aerobic training. However, aerobic and muscular endurance training must utilize certain protocols / variables to ensure optimal increases in VO2 max, MBC, maximal oxygen uptake, while still being capable of increasing strength and power, which lead to the greatest gains in athletic performance. Cross fit, simply put, often neglect numerous variables / protocols.

One style of training that is advantageous, that cross fit does perform is Circuit Training. Circuit training is a method of training that requires high volume coupled with short rest periods of 30 seconds or less [1]. This style of training has shown to increase relative VO2 max. This is vital for anaerobic athletes who require elevated aerobic-endurance levels. The most widely accepted measure of cardio respiratory vigor is Maximal Oxygen Uptake, which is the greatest amount of oxygen that the body can utilize at the cellular level. The goal of aerobic athletes, and cross energy athletes is often to increase these levels through circuit style training.Circuit training should utilize functional movement patterns that are similar to movements of the sport. It is not necessary, nor is it beneficial, to re-create exact anatomically based movements. An analysis of the muscles activated during the sport / activity is needed first and foremost. Following this analysis is a re-creation of competition speeds and muscular recruitment during training. Muscular recruitment and movement are most advantageous when re-created during training to be similar to the sport. On the other hand, there is a high degree of cross over between exercises and movements utilized for multiple sports. A common mis-conception is that movements must anatomically look the exact same as the sport itself, this is not Functional Training. The variables of the program make the difference, which are the sets, reps, rest time, structure, and placement of the exercises. Having a goal in mind will provide you with a solid structure leading to optimal athletic performance. A plan with random exercises, just to get a high amount of work done, is undesirable and not a plan. Cross fit takes that extreme.Cross fit does not utilize a sport or athletic analysis to individualize or customize a program that has similar recruitment patterns to that of the sport itself. Cross fit believes in “one size fits all.”

Cross fit coaches utilize nearly all of the same movements for their participants; clean to press, snatch, kipping pull ups, kettle bell swings, and others… Although some of these movements (never kipping pull ups) can often be advantageous, utilizing them with a plan based upon sets, reps, rest time, and placement in a workout are essential for creating optimal and superior results. Cross fit often places exercises into a workout resulting in weight reduction and improper technique, while still expecting performance increases. Not only does this not increase performance, it often decreases performance, especially with previous athletically trained athletes. Another negative aspect is that this style of training and program structure, or lack-there-of, can lead to injury and periods of detraining.Training with larger muscles, or recruiting more than one muscle in a movement, is done through compound movements / lifts. This is often advantageous because oxygen demand increases during an acute bout of aerobic exercise [1]. Cross fit takes advantage of this by utilizing total body movements throughout the entirety of its workouts. This increases its MET (metabolic equivalent of tasks) levels, which is common when assessing the level of intensity of an exercise / workout. Higher levels of MET’s are associated with increased metabolic rates, heart rates, and an overall energy output. MET workouts often lead to decreased fat levels and improved body composition, resulting in athletic performance. Incorporating large muscular movements during repeated bouts of exercise will deplete energy stores, such as ATP and creatine phosphate, which results in an inability to perform the movement correctly, efficiently, and with optimal strength and power. Exhaustion, due to energy store depletion, leads to injury, improper muscular recruitment (zero athletic performance), a reduction in weight, a loss in strength and power, and an overall slower movement pattern. The body becomes adapted quickly and atrophies even quicker. This reduction in weight, which is often required when performing numerous bouts of intense reps, leads to a slower athlete, a less powerful athlete, a weaker athlete, a more injury prone athlete, a less capable athlete, and a less coordinated athlete (Cross Fit: Does it really achieve the results it claims? Part I). Finding a balance between endurance and strength is needed for every athlete.

Strength is a common misunderstood term. Fitness enthusiasts and athletes think of strength as slow and power as explosive / fast. This cannot be further from the truth. Strength and power reflect the ability of a muscle to exert force at any given speed [1]. A stronger athlete is often more powerful and vice-versa. Training for strength and power is a critical component for all athletics. Soccer athletes train for strength and power in order to increase sprint speed, agility, and quickness. Swimming athletes train for strength and power in order to increase their concentric contraction during each pull of their stroke and to increase the push off from the wall. Athletes in sports like these, along with many others, require a higher oxygen uptake and MBC. They have been shown to enhance athletic performance through strength training. Anaerobic exercise has proven to increase cross-sectional areas, neurological coordination, flexibility, aerobic capacity, motor performance, local muscular endurance, lean muscle tissue, metabolic rates / efficiency, and power. All of these side effects are significant, resulting in a more developed / better athlete. Cross fit does not provide the same benefits because it does not practice safe and efficient strength training.

Type II muscle fibers are fast twitch and Type I are slow twitch. Type I are more oxidative (aerobic) and type II are associated with strength and power (anaerobic). However, the common claim is that aerobic endurance training will change type II to type I. There is little evidence to support this claim [1]. Continually performing strength and power training, even coupled with aerobic-endurance training, will not only maintain type II fibers, but it increases type II fibers. One side effect of aerobic endurance training is a gradual change from type IIx fibers to type IIa fibers. Type IIa fibers are more functional then type IIx fibers. Type IIa fibers posses a greater oxidative capacity and are more advantageous when performing repeated bouts of exercise. Repeated bouts of movements are required in nearly all sports. Therefore, one can theorize that coupling aerobic muscular endurance training with anaerobic strength training will result in superior athletic performance. One exception to the rule is Olympic Power lifters. Olympic lifting athletes are made up of mainly IIx fibers. This is advantageous for the sport of Olympic lifting, but it often leads to a poorly trained athlete as a whole.

It is essential to engage in a program that utilizes strength and power training and aerobic endurance or local muscular endurance training. “Acute aerobic exercise results in increased cardiac output, stroke volume, heart rate, oxygen uptake, systolic blood pressure (pressure exerted against arterial walls as blood is forcefully ejected during ventricular contraction and combined with heart rate measures work of heart), and blood flow to active muscles and a decrease in diastolic blood pressure (estimate pressure against arterial walls when no blood is being forcefully ejected through the vessels)” [1-125]. Cross fit can aid in the ability of select athletes, generally beginner to amateur athletes, with an increased ability of muscular endurance for increased performance. However, there is a trade off. With cross fit’s minute gain in endurance, one can expect a loss in absolute strength and power, which will result in poor athletic performance, a reduction in speed, improper technique, minimal injury prevention training, a reduction in agility, lower back pain, and many other non-desirable side effects.For athletes who are involved in a sport or activity that require a high aerobic output and/or MBC, utilizing a proper strength and conditioning program will ensure optimal gains in athletic performance. Develop a program that balances between strength and power and muscular endurance / aerobic training. Here is an example:Day 1: Strength & Power – Lower BodyDay 2: Endurance / Circuit – Upper BodyDay 4 or 5: Endurance / Circuit – Lower BodyDay 5 or 6: Strength & Power – Upper BodyThis is nothing more than a sample weekly regimen. Provided that you give 100% effort, follow the plan, perform proper technique during exercise, place equal emphasis on all the training days, and observe all program variables, you can expect to become a superior athlete. An athlete who can dominate both aerobically and anaerobically, an elite hybrid athlete.SOURCESwww.functionalmusclefitness.com1. The Essentials of Strength Training and Conditioning (3rd edition).By, National Strength and Conditioning AssociationEditors: Thomas R. Baechle and Roger W. Earle©2008, 2000, 1994[113, 123, 125, 129]2. NASM Essentials of Personal Fitness Training (3rd edition)By, National Academy of Sports MedicineEditors: Michael A. Clark, Scott C. Lucett and Rodney J. Corn©20083. Strength Training Anatomy (3rd edition)By, Frederic Delavier©2010 by Editions Vigot