I am a 64 year old Vermont physician who has been biking for years. As my interest in winter sports waned over the years, I turned to the Concept2 rowing machine for my winter exercise. I try to do 5000 meters a day while watching quality movies with cordless earphones. I hope to keep it up for years to come. I usually do it in the morning after my coffee and find that it energizes me for the whole day.