After age 40, to combat the aging of muscles and tendons, physical exercise acts as an adaptation signal that must absolutely be supported by adequate nutritional intake (the fuel), otherwise you risk greatly limiting the benefits of your efforts.

noli's read

The idea that physical exercise is a 'signal' requiring nutrients to materialize is scientifically very robust, particularly after age 40. For muscles, dozens of randomized controlled trials (RCTs) and meta-analyses confirm the existence of a decrease in the efficiency of reconstruction signals with age, necessitating the consumption of more quality protein to trigger repair. Regarding tendons, the work of Dr. Keith Baar (combining expert opinion and clinical studies) demonstrates that movement associated with specific nutrients like collagen and vitamin C directly stimulates tissue regeneration. The assertion that one 'leaves adaptations on the table' without this nutrition is therefore entirely accurate for adults over 40 who train regularly. While the importance of an immediate post-workout nutritional window is sometimes slightly overestimated in the wellness community, overall nutritional intake remains a crucial limiting factor for physical longevity.

the sources

No named source held this one up — that absence is part of the verdict.