Disclaimer: The information in this article is general in nature and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor or other qualified health professional before starting any exercise programme or with any questions you may have regarding a medical condition.
Swimming can improve aerobic fitness while placing less load on knees and ankles than many land activities. Its benefits depend on how hard, often and safely you swim. It is exercise, not a treatment for joint pain, depression or injury.
Why swimming places less load on joints
Water supports your body, which reduces pressure on weight-bearing joints such as knees and ankles. Healthdirect describes swimming as a low-impact sport and a full-body resistance exercise. This combination can work your heart and muscles without repeated foot strikes.
Low impact does not mean injury-proof. Poor technique or a rapid increase in distance can irritate the shoulders. Healthdirect's shoulder advice is to learn sound stroke technique and build distance gradually.
The strongest fitness evidence
A 2017 systematic review found 29 eligible studies of non-elite swimmers. Compared with control groups, swimming improved maximal oxygen uptake, a standard measure of aerobic fitness. The results varied by population, and the authors called for more high-quality trials.
Another research review covered 62 randomised trials of swimming and other water-based training. Healthy adults improved strength, balance and aerobic fitness. The useful programmes generally lasted at least 12 weeks, with two or three sessions of 46 to 65 minutes each week.
That review did not test lap swimming alone. It cannot show that one stroke, pace or session length is best for everyone.
Mental wellbeing claims need care
The evidence for mental wellbeing is promising, but it is not settled. An evidence review of 18 trials reported improved mood and anxiety symptoms after aquatic exercise. The studies mixed swimming, aqua aerobics and different populations, and their results varied widely. The authors called for larger, higher-quality studies.
Swimming should not be presented as a treatment for PTSD or depression. It may be an enjoyable form of activity, but people needing mental health care should seek qualified support.
How swimming fits Australian activity targets
Current adult guidance recommends at least 30 minutes of moderate-to-vigorous activity on most days. It also recommends muscle-strengthening activities on two or more days each week. Mobility, balance and coordination activities are recommended on three or more days.
A swim can contribute to the aerobic target when it raises your breathing and heart rate. Healthdirect notes that swimming can become high-intensity exercise when you swim fast. Easy floating and technique practice may not reach that effort. Swimming also does not automatically cover every strength and balance target.
Progress by time, distance or effort instead of treating one calorie estimate as universal.
Starting when you are not confident in water
You do not need to begin with laps. ABC reporter Kate O'Halloran documented her adult lessons in Melbourne during 2025. Her first lesson focused on walking and floating, and she trained twice each week. Her experience shows why lessons can start with water confidence rather than distance.
Use KeepActive's venue search to find local pools, then ask whether adult lessons or beginner sessions are offered. If you cannot swim safely, choose a lifeguarded pool and learn with a qualified instructor.
Pool swimming and open water require different safety decisions. At beaches, Australian Government water safety advice says to swim between the red-and-yellow flags. Check signs, conditions and warnings, and do not swim alone. If conditions are unsafe, stay out of the water.
