Health experts say that in order to gain any benefit from exercise people need to get in a sweat.
They say current guidelines from the World Health Organization (WHO) that say 30 minutes of gentle exercise each day is enough to sustain a minimum level of fitness, is misleading advice and could encourage people to do too little exercise.
The experts from the American College of Sports Medicine say in order to remain healthy people need to do at least 30 minutes of moderate exercise five days a week, or 20 minutes of vigorous exercise, such as jogging, three days a week.
The sports scientists are concerned that the official advice to do 30 minutes of gentle exercise each day is being misconstrued to include a mere stroll to the car.
They say there is confusion about what is the ideal amount and intensity of exercise to improve health.
Experts all agree that exercise is beneficial to the health and recent research by scientists at Queen's University, Belfast, found that walking for half an hour on just three days a week gave similar fitness and blood pressure benefits to walking for 30 minutes five times a week.
The sports scientists include experts on a high-level committee in the States who are considered to be world leaders in public health.
They have been involved in the development of new physical activity guidelines for U.S. citizens and their recommendations in 1995 were adopted by the WHO and by the UK government.
The team now stress that adults need to top up their routine activities, such as casual walking and housework, with structured exercise and the new advice includes the following guidelines for adults aged 18- 65 :-