Cardio acutely increases output and blood pressure, which forces the body to adapt leading to a lower resting heart rate and cardiac hypertrophy.

Nystoriak MA, Bhatnagar A. Cardiovascular Effects and Benefits of Exercise. Front Cardiovasc Med. 2018 Sep 28;5:135. doi: 10.3389/fcvm.2018.00135. PMID: 30324108; PMCID: PMC6172294.