I have just completed my first triathlon (only the novice distance so far). I have had spondylolisthesis for 20 years. It never gives me any problem with exercise, but it does with work. I am a midwife, and at present I'm recovering from lifting a woman who had fainted. I am currently only doing Pilates, walking daily and some swimming on doctor's orders, but I'm worried that I am going to lose my level of fitness.

Many people have spondylolisthesis, a condition in which one vertebra slips on another, and have no symptoms. Symptoms usually come from spinal nerves, which may be pinched as the vertebrae slip forward. The analogy I like to give is that your spine is like a stack of peanut butter sandwiches, the peanut butter representing the soft spinal discs which, when compressed, can press on nerve tissue, triggering pain. You're right to decrease your training, as rest relieves symptoms,so you are going to need a large dose of patience. It strikes me that you are results-driven, so redirecting your fitness objectives to follow a specific plan for health and disease protection may help. Many people view vigorous, intense exercise as their best investment for health; the evidence, however, supports the case for moderate exercise to improve overall health. Your body may lose its fitness, but it does not necessarily forget. Once your symptoms have improved, take comfort from the fact that with a progressive plan you will regain your fitness far quicker than an individual who has never exercised. This will become even easier if you invest in your health with your daily walking targets and back mobility classes. This is the time to adopt a whole-body approach to your fitness, and to complement this with stretching, balance and posture work. These will be your building blocks to a healthy and, in time, fitter body than right now.

· Joanna Hall is a fitness and exercise expert (joannahall.com). Send queries to: Weekend, 119 Farringdon Road, London EC1R 3ER (weekend@theguardian.com).