All good answers. I would only add that you can suggest to your client that he/she focus on how his/her energy level throughout the day compares now with what it used to be. Also have him/her check their wardrobe. Have their been any changes in clothing sizes? It can be a strong motivator.
It depends on my cleints goals. If they are training for weight loss we do a weekly weigh in and I measure their waist every 6 weeks.
If it’s for strength I keep track of what they started with and where they are today.
I’ll remind them that when we started they could only do 6 pushups, as they are completing their 20th one.
For my bootcampers, they gauge themselves on how much “easier’ our hill climbs are or how much “easier” it is to breathe!
I also use a lot of the same assessments as those mentioned above. But I also take photos of all my clients when they start. A front on shot and a profile shot. Not only does this provide me additional info. regarding alignment, but after 90 days, I take another set of photos and then send them to the client, side by side with their reassessment results. A photo doesn’t lie and most of my clients are surprised by the changes. They see themselves in the mirror everyday, so they often don’t see how far they’ve come.
For weight management I prefer body measurements with measuring tape because body fat can be difficult and uncomfortable to measure with calipers especially if the clients skin is very tight and the skinfold does not pull away from the muscle and bone. Other methods are less accurate or more expensive.