Older men and women make similar muscle gains relative to their body size from resistance training, a new Australian study shows.

Men might get bigger muscles, but lifting weights at the gym benefits women just as much, a new Australian study shows.

Older men and older women make similar gains relative to their body size when doing resistance training, the research suggests.

A team of researchers from the University of New South Wales looked at the results of 30 resistance training studies with over 1400 participants, and compared the results for men and women aged 50 and over who mostly had no prior resistance-training experience.

The men and women had similar changes in relative muscle size and upper body strength, but women had better improvements in relative lower body strength.

Relative changes are based on a percentage of a person's body size, whereas an absolute approach only looks at overall gains.

Men were more likely to gain absolute muscle size.

Resistance training helps people to feel stronger but also increases their stamina, flexibility and bone density.

The researchers hope their findings will influence trainers when designing exercise programs.

"It's important for trainers to understand that women benefit just as much as men in terms of relative improvement compared to their baseline," Dr Amanda Hagstrom, exercise science lecturer and senior author of the study, said in a statement.

To maximise training benefits, older men should consider doing higher intensity programs to improve absolute upper and lower body strength, Dr Hagstrom said.

"But older women might benefit from higher overall exercise volumes - that is, more weekly repetitions - to increase their relative and absolute lower body strength," she said.

Previous research has shown that younger men and women, aged between 18 and 50, can also achieve similar relative muscle size gains from strength training.