If you want to design a safe and effective training program use the 2 essential rules listed below as guidance. Do your best to make them your priority and keep them in order. Remember, an injured athlete can't improve, or perform.
Through all my research I have not found an article that has done a better job than "Training the Energy Systems" by the late Dr. Fritz Hagerman. Dr. Hagerman was the exercise physiologist for the U.S. National team for about 30 years. I cannot begin to express my gratitude for his contributions to the sport of rowing. I've attached the document below since it has been rather difficult to find online. If you would like a copy sent to you in an email feel free to contact me.
I profiled a few key points that stood out to me, and that help to define my program, but please take the time to read the article for yourself. There is a treasure trove of information in these 8 pages. It took me about a year of research to learn all of this on my own. You will be saving yourself a lot of time by diving into this piece of work.