Observations From Assessing Advanced Crossfit Athletes
How an athlete solves the problems imposed by whole-body exercise (i.e. regulating blood pressure, supplying O2 to the brain/ heart/ priority muscle groups, dealing with changes in intra-abdominal pressure and subsequent blood flow) is a large determiner in Crossfit performance.
Some athletes have better ways of solving this than others, but make no mistake - everyone has a limit.
Over the past few years i've conducted physiological assessments on dozens of Crossfit athletes ranging from recreational competitors to top games competitors. Some things i've learned over this time are...
1. Mitochondrial density and cardiac output do not always develop in tandem with one another. This can pan out in one of two ways. Some athletes present with great cardiac output, but a poor ability to utilize oxygen in the working muscle at a fast enough rate. On the flip side, we also have athletes who have excellent local muscular endurance, but couldn't deliver enough blood and O2 to the working muscle if their life depends on it (in some ways, it does...). Often times the former come from endurance or field sport backgrounds like soccer/ lacrose and the later come from sports like hockey, football, or they just love to hit the weights and skipped cardio for a decade or two
2. A lot of 'bubble' level games/ sanctional athletes have great mitochondrial/ capillary, but really lack strong delivery or cardiac output. In these athletes, blood pressure limits blood flow until the brain is 'comfortable' with the situation. The result ? A lot of 'pumping out' or 'blowing up' in workouts that involve alternation of muscle groups. This makes me question if these athletes should really be doing a lot of repeat sprint work, high end strength training, or 'anaerobic' work. Aren't we just making the problem much worse ? (This would be akin to trying to save more money, but simultaneously increasing your spending rate)
3. A lot of high level athletes in the sport present with stellar delivery capabilities, great mitochondrial / capillary density, but a lagging respiratory system. Oxygen supply in the muscle will lag during gas exchange at the highest intensities or under heavy fatigue. Maybe that's why these athletes don't benefit (and get worse) from the hypoxic breath work (wim hoff, power speed endurance, etc) that has gained so much traction in the CF realm over the past few years
4.Elite Crossfit athletes have excellent cariac output, a well developed respiratory system, high levels of sport-specific strength, high mitochondrial/ capillary density, and optimal sympathetic drive. This results in steady tHB levels/blood flow trends even during mixed work. These athletes turn mixed work into cyclical work inside the muscle. Literally.
We may not be able to change an athletes genetics, but we can certainly augment what they have if we know what we're dealing with. My approach:
(1) Address the funadmentals. Movement quality, breathing mechanics/ volume (movement specific), pre-position, coordination
(2) Address physiological limitations as best we can
(3) tackle sport specific limitations next. This ordering ensures we take care of structure before function
(4) address specific movement 'capacity' issues.