What do they do? More practical than dumbbells, wrist weights can be used to do exercises standing up (to strengthening your muscles), or they can be used whilst walking or running (to intensify your workout).
How do I choose the right ones? For maximum comfort and safety, check first of all that the material can be properly extended so you can adjust them properly. Like with dumbbells, you then need to choose which weight you want (from 250g to 1kg). Go for lighter ones: it's better to do a longer endurance workout than a short, intense one.
How often should I use them? The ballasts intensify the exercises you do to strengthen the upper body. More weight can lead to more strain on your body, so ays ensure that your back is kept straight. To give your muscles a break, don't do more than 2 to 3 sessions per week.
Reebok Wrist and Ankle Weights (2 x 0.5kg), £11.99