Part II: Does Cross Fit lessen athletic performance: lean muscle growth, fat loss

Article by Mark Wine CSCS ; NASM PT, CES, PES

Cross fit has numerous stories of body weight reduction. Is this reduction fat loss? Generally speaking sports require a certain body fat percentage, or lean mass versus fat mass. Fat reduction becomes essential in order to be successful. Sports like mixed martial arts (MMA), football, hockey, soccer, swimming, tennis, and so on… Because you need a significant amount of lean muscle, with lower body fat levels, should these athletes participate in cross fit? Sports like baseball, golf, or a football lineman can pack on a little extra weight, a little more fat, should they stay away from cross fit? Cross Fit moves at a high intensity pace for a long period of time. Experts in the field of fitness say that ‘in order to burn more fat you want less rest between exercise sets. Experts in the field claim ‘performing complex total body movements, instead of isolating one specific muscle, is preferred.’ This is true. Cross Fit performs complex movements with minimal rest periods, so this must mean Cross Fit is works? If only it were that simple. Cross Fit participants often lighten the load below 70% of their 1RM (one rep max). The best way to gain lean muscle mass is by increasing the weight, so your body doesn’t become adapted to the specific imposed demands placed upon it. Calorie expenditure increases, the resting metabolic rate (RMR) increases, and extended post exercise oxygen consumption (EPOC) is extended. RMR is your metabolic rate when you are no active, you are at complete rest. EPOC is the oxygen consumption post exercise, which aids in increasing your calorie expenditure. Lighter weight, or constantly performing the same exercises with the same weight, falls short in achieving these four results. However, can only using light weight increase fat loss? Does this mean you can’t expect gains in performance due to body weight reduction through Cross Fit? Intermediate to advanced athletes cannot expect optimal results from Cross Fit. If you are a beginner exercising or beginning Cross Fit for the first time then you can expect body weight reduction; fat loss; lean muscle growth; and your athleticism may improve. At the same time, if you engage in any new proper exercise program you can expect these results. The best best way to gain lean muscle and achieve optimal fat loss is through resistance training, with weight that makes you struggle. You want to pick up weight that makes you struggle to achieve the desired repetitions, usually around 6-12, with under 60-90 seconds of rest. Cross Fit is extremely limited in this regard because they do not use weight that fits to that repetition count; therefore, Cross Fit does not lead to maximal athletic performance. Lean mass (muscle) is produced by resistance training, so let us look further into Resistance Training. Resistance training can be anything from body weight training, suspension training, plyometric training, and/or weight lifting. Simply put, being physically active will build some lean muscle. However, not all methods of resistance training are equal. For example, only performing pushups as your whole workout method will stimulate muscle growth for a short while, if you have never trained before. However, once your body has adapted to this motion and weight, more resistance must be added on. We do this by using dumbbells, barbells, changing the pushup to suspension training pushups and other variations. This is one reason Cross Fit has weaknesses. Cross Fit’s rep speed, volume of reps, the energy depletion within your muscles (ATP / CP reduction), all result in an external stimulus weight reduction. Therefore, lean muscle mass will not be stimulated for optimal growth. Without this growth, strength and power gains are limited. Without strength & power gains, in fact, sometimes even a strength & power reduction, athletes can expect to become slower, weaker, more injury prone, and less athletically talented. As an athlete, the constant stimulation of new lean muscle growth is necessary; if nothing more, maintaining muscle is essential if you are in season. During Part I of Cross Fit: Does it really achieve the results it claims?, the correlation between strength and power was made. Power development is important to becoming a better athlete. The more lean mass, the higher power output. The higher the power output, the more explosive you are. The more explosive you are, the faster / quicker you are. Cross Fit performs the same structured workout routines, as well as the same exercises, on a continual basis. There are some variations here and there. Eventually the body becomes adapted and any results diminish. One exercise that Cross Fit performs over and over again is jumping pull ups, which stimulates nearly zero back muscle growth. Ask a Cross Fit participant to perform a Military pull up, which requires actual back strength. The majority cannot. A real life example; a female athlete, whom worked out at Functional Muscle Fitness LLC, received a Division I scholarship from a Pac-12 University. She developed her core and strength / power while training properly. She is involved with a sport that requires high amounts of muscular endurance and power. When she arrived at her university she was asked to perform a pull up test with the rest of her team. She performed 13 Military style Pull Ups. The other girls performed 20-30 Cross Fit pull ups. When the new Strength and Conditioning Coach asked the other girls to perform a correct pull up, a non Cross Fit pull up, the majority could not perform one. The athlete from Functional Muscle Fitness LLC is one of their top performers. This is just one of many examples of Cross Fit’s weaknesses. Sports that require a significant amount of muscular endurance to perform include MMA, soccer, swimming, tennis, hockey, and any other sport involving fast paced movements. Normally these movements are engaged for longer than 30 second of high intensity bouts, with minimal rest time. These sports could benefit from performing a workout similar to that of Cross Fit. However, like any other sport, these sports also require high power outputs. Therefore, training the Cross Fit way will result in a decrease in athletic performance, unless coupled with a proper Strength and Conditioning program. So how do you incorporate training for muscular endurance, without jeopardizing power gains? Functional Muscle Fitness LLC suggests a 2:2 day split for those sports, maybe even a 3:1 split; Two-Three days would be strength & power training, with one-two days for muscular endurance. Sports that require less mass and less muscular surface area can optimize strength & power growth through supersets. Supersets are coupling two or three exercises together; example, perform dmbl bench, followed by push up jumps. This will ensure more fat loss, with less mass gain. You can train for both muscular endurance and power gains this way. Besides, why not leave the specific sport endurance to playing the sport??? Is it not optimal to learn how to play the sport by playing the sport?

SOURCES1. 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

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©2008

3. Strength Training Anatomy (3rd edition)By, Frederic Delavier©2010 by Editions Vigot

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