Surprise! You might not be as fit as you think …

Fitness goes way beyond muscle and fat. Just because you run marathons or do Crossfit, doesn't mean that injury, sleep, or other bottlenecks won't get in the way of optimal fitness (if they haven’t already, that is).

Our evidence-based analysis features 19 unique references to scientific papers.

Written by Kamal Patel
Last Updated:

Think you’re fit? While you might be correct, you might also be missing something important.

Let’s look at two common examples, and then see if you can improve your fitness levels and body composition without sweating more.

1. I’m the definition of fitness … I’m a Crossfitter/marathoner/etc!

It’s difficult to tease apart the fitness impacts of something like marathon running or CrossFit through a scientific study.

You can’t just randomize a hundred people to run a three marathons a year, and a hundred others to run no marathons. Adherence in the marathon group would be … low.

When it comes to CrossFit, it almost certainly improves many aspects of fitness, and is even more likely to foster motivation and a sense of community.[1]

Marathoners are a healthy bunch, by and large. Long-term marathon running is associated with less coronary plaque in both men[2] and women.[3] Running in general seems to provide cardiovascular benefits, increasing in magnitude the more years you run.[4]

So what’s the holdup with marathon-running and CrossFit? It’s that ol’ Examine refrain: mind your dosage.

Marathon runners with higher training level have more chronic knee lesions than marathon runners with lower training level.[5] Case reports occasionally pop up of rhabdomyolysis (rapid and dangerous muscle breakdown from overly strenuous activity) after CrossFit.[6] 

Long-term marathon running can increase the risk of heart tissue fibrosis,[7] although the evidence is still mixed as to how harmful this is for most runners.[8] There’s also a small but non-negligible risk of death from actually running a marathon, especially in older males,[9] a group in which cardiac-arrest rates during marathons have been increasing over the past few years.[10]

Looking fit and exercising a lot doesn't necessarily mean you're fit. In some proportion of those cases, overall fitness (via injuries and possible mortality risk) can be worsened.

2. Well, my cholesterol is really low, so …

Cardiovascular fitness is a cornerstone of overall fitness. And since low LDL is a predictor of lower heart disease risk,[11] you might feel pretty proud of your super low LDL.

There’s a couple problems here though. The LDL that’s reported by your doctor (LDL-C) doesn’t always align with the number of LDL particles floating around (LDL-P), and LDL-P is a better predictor of heart disease.[12] 

But more importantly, very low cholesterol has been associated with higher risk of heart disease in a few different studies.[13][14][15] 

This is a very complex topic though; if you want to learn more, check out our comprehensive post on saturated fat research.

If you passed your basic cholesterol screening with flying colors, then ... that still doesn't mean you're fit.

Want to optimize your body and your fitness levels? You don’t need to sweat it!

What do these two examples above have in common? They look at fitness through narrow lenses. Fitness is not just about working up a big sweat. It doesn’t mean having insta-worthy abs or exercising two hours a day.

Fitness is a mix of several components:

  • Optimal cardiovascular function

  • Joints that don’t cause you pain

  • Enough muscle and low enough fat to meet your goals

  • Good hormonal balance

  • Sufficient daily sleep to support all of the above

A lot of people think that you need to exercise more and more if you want better fitness and a better body. Not true!

The most common bottlenecks to optimal fitness are rarely a lack of training time, but more often things like persistent sleep issues[16][17] or chronic joint pain.[18][19] 

As the evidence has built up over the past few years on ways to address these bottlenecks, we’ve slowly and methodically collected the studies and analyzed them. More than 300 studies later, we combined everything together into a step-by-step blueprint:

  • Address common bottlenecks through targeted nutrition and supplementation

  • Tackle dieting psychology, an incredibly common stumbling block

  • Understand the recent evidence behind popular diets

  • Discover the answers to the most frequently-asked dieting questions we get

  • Address non-exercise movement (like your body positioning at work)

  • Find how best to track your progress and set realistic fitness goals

  • Keep your joints healthy, so you don’t get pain from getting more “fit”

If you’re that magical unicorn who sleeps perfectly, has perfect body composition and joint health, and is crushing it in every single facet of life, then … congratulations! But for all the regular humans out there, it may be worth checking out our most comprehensive product, the result of years of evidence-collection:

It’s the only guide out there that thoroughly covers the multiple factors impacting fitness, and also gives step-by-step directions based on the most recent scientific evidence.

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  1. ^ Claudino JG, et al. CrossFit Overview: Systematic Review and Meta-analysis. Sports Med Open. (2018)
  2. ^ Roberts WO, et al. Fifty Men, 3510 Marathons, Cardiac Risk Factors, and Coronary Artery Calcium Scores. Med Sci Sports Exerc. (2017)
  3. ^ Roberts WO, et al. Long-Term Marathon Running Is Associated with Low Coronary Plaque Formation in Women. Med Sci Sports Exerc. (2017)
  4. ^ Hespanhol Junior LC, et al. Meta-Analyses of the Effects of Habitual Running on Indices of Health in Physically Inactive Adults. Sports Med. (2015)
  5. ^ Schueller-Weidekamm C, et al. Incidence of chronic knee lesions in long-distance runners based on training level: findings at MRI. Eur J Radiol. (2006)
  6. ^ Meyer M, Sundaram S, Schafhalter-Zoppoth I. Exertional and CrossFit-Induced Rhabdomyolysis. Clin J Sport Med. (2018)
  7. ^ Patil HR, et al. Cardiovascular damage resulting from chronic excessive endurance exercise. Mo Med. (2012)
  8. ^ Pujadas S, et al. Myocardial remodelling and tissue characterisation by cardiovascular magnetic resonance (CMR) in endurance athletes. BMJ Open Sport Exerc Med. (2018)
  9. ^ Webner D, et al. Sudden cardiac arrest and death in United States marathons. Med Sci Sports Exerc. (2012)
  10. ^ Kim JH, et al. Cardiac arrest during long-distance running races. N Engl J Med. (2012)
  11. ^ Howard BV, et al. LDL cholesterol as a strong predictor of coronary heart disease in diabetic individuals with insulin resistance and low LDL: The Strong Heart Study. Arterioscler Thromb Vasc Biol. (2000)
  12. ^ Otvos JD, et al. Clinical implications of discordance between low-density lipoprotein cholesterol and particle number. J Clin Lipidol. (2011)
  13. ^ Nago N, et al. Low cholesterol is associated with mortality from stroke, heart disease, and cancer: the Jichi Medical School Cohort Study. J Epidemiol. (2011)
  14. ^ Bae JM, et al. Low cholesterol is associated with mortality from cardiovascular diseases: a dynamic cohort study in Korean adults. J Korean Med Sci. (2012)
  15. ^ Ravnskov U, et al. Lack of an association or an inverse association between low-density-lipoprotein cholesterol and mortality in the elderly: a systematic review. BMJ Open. (2016)
  16. ^ Mah CD, et al. The effects of sleep extension on the athletic performance of collegiate basketball players. Sleep. (2011)
  17. ^ VanHelder T, Radomski MW. Sleep deprivation and the effect on exercise performance. Sports Med. (1989)
  18. ^ Hsu CJ, et al. Fear of Reinjury in Athletes. Sports Health. (2017)
  19. ^ Sasaki E, et al. Nocturnal knee pain increases with the severity of knee osteoarthritis, disturbing patient sleep quality. Arthritis Care Res (Hoboken). (2014)