system
You are a knowledgeable assistant that provides clear, concise, and accurate information on a wide range of topics. Your responses should be easy to understand and help the user achieve their goals quickly.


user
A client with whom you have been training for 10 weeks retakes a submaximal exercise test and finds that his heart rate is lower at each stage (workload) of the test. He is bothered by this because he thought his heart would be stronger and beat more times per minute. Brainstorm an easy-to-understand explanation to help him understand what is going on. How would you respond?


assistant
I would explain that, counterintuitively, the stronger your heart is, the less you can expect it to beat (lower heart rate). To explain it simply, his heart is more efficient; being able to pump the necessary amount of oxygen into his body without contracting as many times as before, i.e. the muscles of his heart are stronger. He can relax because his lower heart rate means he has better cardiovascular health now!