I've tried to stay off this for a while, but I really need to chime in here on the whole "lose fat, gain muscle" thing as it relates to athletic performance. It is an extremely myopic view of performance factors and a gross oversimplification of what is happening. It shows a strong bias towards the big for nothing, all show no go bodybuilding/aesthetics realm of understanding for pure hypertrophy and fat loss. Just as calorie excesses/deficits and cut/bulk cycles are bullsh*t in a vacuum, bigger=stronger and leaner=quicker is bullsh*t in a vacuum...especially when we start talking about how 3-5% bodyfat is good for athletes in a game largely determined by recovery. Their endocrine systems would be thrashed at that low a level without serious augmentation with a very short half life delivered via nearly daily injection (GH). This is exactly why you see nearly every player on the teams between 7 and 25 percent depending on position with the real superathletes like backers, backs, and ends being all right around 10%.
Got off topic there, but real world explosion and power are not generated solely by the amount of skeletal muscle one has. It's a far more complicated equation that uses the nervous system, core power, mobility, torque, triple extension, and force generation throughout range of the movement. That's why there's obese 5'9 Olympic lifters who can dunk and big for nothing bodybuilders that can't jump onto a 36" box. I'm also a gym rat and every four months I put myself through a hypertrophy phase when I don't have any grappling competitions on the horizon. I usually put on a few pounds of lean muscle in a 4 week mesophase and usually drop a tiny bit of fat while I'm at it. After that phase I am athletically a sack of garbage. Time under tension and single joint isolated contractions against resistance get you big really quick. They also make you a weak b*tch really quick because you down regulate all the pathways activated and conditioned by explosive movements, holistic body engagement, and all the hormones activated by progressive heavy load compound training. Your speed goes to sh*t, your strength goes to sh*t, your explosion goes to sh*t, your anaerobic capacity goes to sh*t, and most of all your recovery goes to sh*t if you are not making functional activations...but you will look like Channing Tatum
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I'm all for players becoming more functionally powerful, explosive, and agile but to continually say an athlete that you don't have a deep understanding of needs to add muscle or lose fat is a gross oversimplification. It's pretty safe to assume that NFL strength and conditioning coaches are world class at what they do and know their athletes very well. Players have playing weight ranges in their contracts for a reason and their goal is not to play at that weight at 2% bf with a spray tan.