We all know we're meant to be doing 150 minutes of moderate exercise, like walking, a week, but how many of us do strength training as well?

A new survey by DW Sports, 40% of people over 65 do no strength exercise at all, while just over half (56%) were doing the NHS recommended two sessions a week 'to work all the major muscles (legs, hips, back, abdomen, chest, shoulders and arms).’

Casey Hewitt, Trainer at high intensity studio, Speedflex: "As you age, your muscle mass naturally decreases, with a noticeable drop when you reach 50. It is always advised that older people continue to exercise for many health benefits, but research suggests that strength training in particular can have significant benefits on over 60’s health.

"Regularly working out in this way builds muscle and replenishes the muscle mass that steadily declines as we age. It also boosts bone density and aids the metabolism. Over time, this could reduce your chances of suffering with arthritis, as it supports the muscles around the joints, and diabetes, due to a boosted metabolism."

What are strength exercises?

The NHS lists the following as suitable strength exercises:

- Carrying or moving heavy loads, such as groceries
- Activities that involve stepping and jumping, such as dancing
- Heavy gardening, such as digging or shovelling
- Exercises that use your body weight for resistance, such as push-ups or sit-ups
- Yoga
- Lifting weights

Why should you be doing strength exercises?

The most important reason is to avoid musculoskeletal conditions, such as osteoarthritis and back pain, which are the leading causes of pain and disability in England, according to the Department for Health.

Britain’s oldest personal trainer, Dr Eddy Diget, 72, is an advocate of strength training for the older generation, especially for women: “In my opinion, females aged 50 plus are most vulnerable to musculoskeletal conditions. They lose calcium in their bones and their joints become dry through lack of ‘lubrication’ (myosin) as they get older. This can give rise to various bone (they become thin) and joint problems, as they do not have much muscle density.

“If they fall, they are more prone to break a bone, even more common is splintering of the bone, not unlike a glass breaking on a solid floor – it’s very hard to repair and this can have devastating effects on the individual and/or family.

“Because of this lack of muscle density, the joints become ‘sloppy’ as the ligaments and tendons lose their elasticity and the bones/joints become unstable as age progresses, just like the elastic in a bra will go first not ‘holding’ nor fitting correctly!

[Read more: Keep fit at any age: Best exercises to do in your 50s, 60s and 70s] 

“But regular strength exercise will keep the muscles tight and joints lubricated, improving posture, flexibility, fitness and health as it tightens these important elements within the body.

“Men, on the other hand, tend to already have muscle density, and because of this, they do have stronger muscles, ligaments and tendons to hold the bones in check and help their flexibility, minimalising the risk of broken bones if they fall. Also myosin, (joint/muscle lubrication) is constantly being generated, due to testosterone.

“Working with weights for both male or female, no matter what age causes muscles to contract and expand, and will go a long way in avoiding loss of calcium, posture, strength, balance and, joint or bone problems.”

Do you do strength exercises? Tell us in the comments box below