Source credit: Medicine & Science in Sports & Exercise via PubMed. DOI: 10.1249/MSS.0000000000004066.
Short summary
A July 3 PubMed record for Medicine & Science in Sports & Exercise reports that higher cardiorespiratory fitness was associated with a slower five-year decline in cystatin C-based kidney-function estimates among adults who began the study with preserved kidney health.
The prospective cohort included 198 participants with a median age of 61.4 years, 74 percent of whom were women. Fitness was measured with gas-exchange analysis during a submaximal exercise test, while kidney function was checked annually for up to five years using both cystatin C-based and creatinine-based eGFR measures.
The signal was specific: higher cardiorespiratory fitness was linked with a slower decline in cystatin C-based eGFR and a lower risk of rapid kidney-function decline. The same association was not seen when creatinine-based eGFR was used, so this should be read as an observational aging-health finding rather than proof that cardio training prevents kidney disease.
Why it matters for lifters
Strength athletes often treat conditioning as optional, but kidney, cardiovascular, and metabolic health all affect long-term training capacity. This study supports a practical point: maintaining aerobic fitness may be part of staying trainable as you age, even if your main sport is lifting.
For lifters, the takeaway is not to replace progressive resistance training with endurance work. It is to keep enough regular conditioning in the week to support recovery, blood-pressure control, work capacity, and general health markers that matter over decades.
What to watch next
Future research needs to test whether improving cardiorespiratory fitness changes kidney-function trajectories, not just whether fitter people show better outcomes. It will also be useful to see whether similar patterns appear in younger strength athletes, people with hypertension, and people using high-protein diets under medical supervision.
Health disclaimer: This article is for informational purposes only and is not medical advice. If you have kidney disease, high blood pressure, diabetes, or concerns about exercise intensity, work with a qualified clinician before changing your training or nutrition plan.