have you asked your client how he feels about his progress? As trainers, we are often very keyed into numbers on the chart, how much weight and how many reps lifted, and that is one way of doing things. But a client of 70 years of age often has goals different from that.
I am not suggesting ‘don’t bother about progress’ but you could, with your client, establish certain goals and measure against it. This could be any number of things: the ability to walk or run a certain distance for 30 minutes, or performing certain tasks of daily living that were difficult before like walking stairs. Older clients tend to look at progress often more along those lines.