•Encourage teens to keep one team sport, if possible.
•For teens not into team sports, swimming or athletics are good.
In your 20s
You are at your physical peak, with the fastest reaction times and highest VO2 max - the maximum rate at which the body can pump oxygen to muscles. After this peak, your VO2 max decreases by up to 1 per cent each year and your reaction time slows each year. Regular physical activity can slow this decline. Building lean muscle mass and bone density at this age helps you retain them in later years.
•Vary your training and keep it fun. Try tag rugby, rowing or boot camp.
•If you are a regular exerciser, get advice from an exercise professional to build "periodisation" into your training regime - such as intensity, volume and type of exercise - to optimise your performance and ensure you peak for a planned exercise event.
In your 30s
It is important you maintain cardiovascular fitness and strength to slow normal physical decline. If you have a sedentary job, make sure you maintain good posture and break up long periods of sitting by forcing activity into your day so you are moving every half an hour where possible.
•Work smart. Try high-intensity interval training, where bursts of high-intensity activity, up to 80 per cent of your maximum heart rate, such as sprinting and cycling, are broken up with lower-intensity exercise.
•For all women, and especially after childbirth, do pelvic floor exercises daily to help prevent incontinence.
•Diversify your exercise programme to keep it interesting. Try boot camp, spin class or yoga.
In your 40s
Most people start to put on weight. Resistance exercise is the best way to optimise calorie burning to counteract fat accumulation and reverse the loss of 3 to 8 per cent of muscle mass per decade. Ten weeks of resistance training could increase lean weight by 1.4kg, increase resting metabolic rate by 7 per cent and decrease fat weight by 1.8kg.
•Try kettlebells or start a weight-training programme in your gym.
•Take up running, if you don't already. You get more bang for your buck with running versus walking.
•Pilates can build core strength to protect against back pain, which often starts in this decade.
In your 50s
Aches and pains may crop up and chronic conditions, such as type 2 diabetes and cardiovascular disease, can manifest. As oestrogen declines in postmenopausal women, the risk of heart disease increases.
•Do strength training twice a week to maintain your muscle mass.
•Do weight-bearing exercises, such as walking. Walk fast enough that your breathing rate increases and you break a sweat.
•Try something different. Tai chi can be excellent for balance and relaxation.
In your 60s
Maintaining a high level of physical activity can help prevent cancers and reduces the risk of developing chronic conditions such as heart disease and type 2 diabetes.
•Try ballroom dancing or other dancing; it's a fun and sociable way to exercise.
•Incorporate strength and flexibility exercises twice a week. Aqua-aerobics develops strength using water as resistance.
•Maintain cardiovascular exercise, such as brisk walking.
70s and beyond
Exercise helps prevent frailty and falls, and is important for cognitive function. If you have a period of ill health, try to keep mobile, if possible as strength and fitness can decline rapidly.
•Walk and talk. Instead of inactive visits from family and friends, go for a walk together.
•Incorporate strength, balance and cardiovascular exercise. Get advice from a professional if you have several chronic conditions.
Julie Broderick is assistant professor, physiotherapy at Trinity College, Dublin.
This article is republished from The Conversation under a Creative Commons license. Read the original article.