I consider myself to be fit - I swim four times a week and do 18 holes of golf most weekends, which for 65 isn't bad - but I'm losing the mobility and strength in my hands. Even opening a jar is a problem.

Almost every action, from tying a shoelace to driving a car, depends on the strength and agility of our hands, wrists and forearms. Yet we expose them to constant physical stress that can damage nerves, tendons, muscles and soft tissues, and may lead to repetitive strain injury or carpal tunnel syndrome. Add to that our growing reliance on push-button appliances, and a loss in grip strength and dexterity is a potential problem for us all, regardless of age.

Simple exercises such as buttoning and unbuttoning a shirt with one hand, playing jacks and opening a tight-fitting lid are good ways to check dexterity and strength, and target the wrist flexors and small muscles of the fingers and hands.

Finger push-ups improve finger and wrist strength. With fingers spread and elbows bent, press your hands firmly together, touching the pads of the fingertips and the palm. Use the tension between the fingertips to arch the fingers out so only the pads touch. Hold the tension as you open. Repeat 15 to 20 times daily. After a week, you can expect to open jars more easily and have a stronger grip.

Try simple ball squeezes,too. Hold a squishy ball firmly in your palm, squeeze and release tension 10 to 15 times. Regular practice will take some of the workload off the wrist extensors, the muscles most likely to be affected by repetitive strain.

· Joanna Hall is a fitness expert (joannahall.com).

· Send your exercise questions to Weekend, 119 Farringdon Road, London EC1R 3ER (weekend@theguardian.com).