A test you can do tonight

The 30-second chair stand is a simple test of leg strength and endurance, from the US Centers for Disease Control and Prevention.

Sit in the middle of a sturdy chair with no arms. Cross your arms over your chest. For 30 seconds, stand up fully and sit back down, as many times as you can. If you need your arms to get up, stop: that’s a score of zero. Have someone stand next to you.

If you are aged 65 to 69, a score below 11 for women, or below 12 for men, is below average.

Write your number down. If it is below average, that is a good signal to start building your leg strength now, and it is worth raising with an exercise physiologist or your doctor.

The World Health Organization’s guidelines include strength work on two or more days a week for every adult. Being active is a good start, but it isn’t the same as being strong.