Are You Fueling for Body Comp or Performance?

I had a fascinating and enlightening exchange with Claude AI about the misconceptions and inherent conflicts between fueling for a perceived ideal body composition (level of muscularity + leanness) versus fueling for athletic performance. It yielded a cohesive explanation of what I already knew, a few small surprises, and this super cool chart (above).

Of course, I could summarize our exchange. You could geek out on the clinical terminology and trace the sources I asked Claude to consult (hint – they’re the same ones I refer to regularly - see my list of references in my profile page on the website and the ones whose content I routinely share in the Facebook group).

But I think what may be more concise and practically useful for you is my providing some clarity and insight on the chart above that Claude provided. Then it will be a more meaningful guide for you. I’ll hit each focus segment, then get into more contextually important details.

Body Comp Focus

Goal: Get as lean and muscular (but mostly lean, for many 50+ hybrid athletes) as possible; willing to subordinate sports performance to get (and try to stay) there.

Myth: You can prioritize extreme leanness (under 15% body fat for men; under 20% for women) without consequentially and chronically jeopardizing sports performance capacity.

Reality: Extreme restrictions of either carbohydrates (CHO) or kcals (the first generally leads to the second, anyway) for an extended period usually erodes performance and causes muscle/strength loss that can be dramatic over time.

Take-home: Limit the severity of the restrictions, the duration, or both, and try to match acute energy needs (pre- and post-WO or event fueling requires more CHO and kcals). Avoid habitual over-restriction, which can cost you both muscle and PRs.

Performance Focus

Goal: Ensure adequate energy and form (macro split) for optimal sports performance.

Myth: Rapidly available, quickly converting energy sources before and during WOs and events is far more important than a chronic balance of macros (CHO, fat, and PRO) and a micronutrient-rich (generally lower in kcals and higher in fiber than other foods) diet.

Reality: Wild swings in CHO and kcal density that result in under-consuming PRO and fat will lead to performance stalls and plateaus. Suppressing PRO, fat, fiber, vitamins, and minerals can severely compromise recovery, which is the cradle of fitness capacity improvement.

Take-home: Accumulating adequate PRO, FAT, and micronutrients as a critical base and adjusting easily absorbed additional CHO incrementally to performance demands is the physiologically sensible fueling approach to preserve long-term performance capacity.

Evidence-Based Middle

Goal: Nail the sweet spot of fueling for performance and ideal body composition.

Myth: The aging athlete can perpetually maintain six-pack abs and optimal conditioning for obstacle course racing or preserve bodybuilder-level contest-level strength/muscle size and definition.

Reality: Realistic expectations regarding sustainable, healthy body fat levels allow older athletes the “headroom” to find their ideal performance energy balance, macro split, and nutrient-dense diet through the practice of evidence-based nutrition principles and continually fine-tuning for their own individual profile to see what works best for them.

Take-home: Paying more attention to how you feel repeatedly during, after, and between WOs is a more reasonable priority than obliterating the thin layer of belly fat that you didn't have in your twenties. The body fat percentage reference points I provided earlier (15% M, 20% F) are, per the National Strength and Conditioning Association, the average levels for 20 - 29 year old Division 1 NCAA athletes. So why are you trying to hit 9% (M) or 14% (F)? Eating an adequate, energy- and nutrient-dense diet is perhaps the most important foundational practice for we older athletes. And a healthy dose of body-acceptance goes a long way as well.