"It's hard to fit in regular sessions around my job as a teacher. It's long hours and I prefer to just have a few per week instead of burning out." she said.

In good news for 'weekend warriors' like Ms Eustace, a new study is suggesting two exercise sessions a week is all that is needed to greatly reduce the risk of cardiovascular disease and cancer.

Four researchers studied exercise data from nearly 63,000 participants over 18 years. They found little difference in health outcomes between the weekend warriors and those who exercise regularly throughout the week.

For instance, the risk of premature death of any cause was 30 per cent lower in weekend warriors and 35 per cent lower in the regularly active. The risk of death by cardiovascular disease was reduced by the same amount (41 per cent while the risk of early death by cancer was 18 per cent and 21 per cent lower respectively.)

The study's lead author, Associate Professor Emmanuel Stamatakis, of the Charles Perkins Centre, suspects the various sports that the majority (94 per cent) of the weekend warriors participated in explains the results.

"The weekend warriors did so well because of increased vigorous physical activity," Professor Stamatakis said. "That's a possible explanation."

"The key message from our study is a little is better than nothing," says Professor Stamatakis of  the research published in the journal JAMA Internal Medicine. "It highlights that a little physical activity can go a long way."

That bodes well for Ms Eustice, who fears adding more to her workload may spoil the fun of exercise.

"Definitely - if I was to push out more sessions, I might end up exhausted and not wanting to go."

The World Health Organisation recommends that adults do at least 150 minutes per week of moderate-intensity activity, or at least 75 minutes per week of vigorous-intensity activity. Surpassing these guidelines leads to additional health benefits.

WHO also lists doing household chores, gardening, dancing, and brisk walking as moderate-intensity exercises while running, fast swimming, and fast cycling are listed as vigorous-intensity exercises.

This means you may not even have to go to the gym to meet your weekly fitness quota.

Professor Stamatakis does note however that they were looking at specific outcomes (premature death) and that the frequency of exercise is still important to other outcomes, like diabetes. Diabetics are advised to exercise at least three days a week and avoid more than two consecutive days without exercising.