A six-week pilot found the body mass index of overweight six-year-olds was reduced after just two 40-minute sessions a week using the equipment.
Children were supervised through a fitness programme using child-size treadmills, bikes, rowing machines, steppers and twisters.
Before the study the average BMI of the children was around 18.5 - between 17.4 and 19.7 is classed as overweight.
The average BMI was reduced to 17.9 after 6 weeks.
Two groups of children at St Dominic's Primary in Airdrie were assessed; 21 in P2 and 20 in P7.
The BMI of the 12-year-olds was within the healthy range before the pilot and did not change significantly.
The Micro Fitness equipment, which was launched by Cumbernauld businessman Steven Reynolds, 26, is now being used in 17 council areas across Scotland, including at Carmyle Primary and Craigholme Primary in Glasgow.
It comes as new research show Scots children are more likely than youngsters elsewhere in the UK to clock up the recommended minimum amount of daily physical activity.
However, only 52.5% of seven-year-olds in Scotland were achieving the basic target of one hour of moderate to vigorous physical activity each day.
Mr Reynolds said: "The cardio equipment allowed young children to engage in physical activity in a way they have never done before.
"The study provided some concrete results that highlighted the strong impact of the mobile gym experience on young children's physical activity levels and BMI.
"All the children were fully enthusiastic and motivated by the equipment and the programme and the uptake was strong for both girls and boys."
The study was carried out by the University of the West of Scotland with funding from the Sporting Chance initiative.
The firm can take up to two classes at a time and say programmes work best at 40-60 minute sessions.
Plans are now underway for a Micro Fitness Centre which will include a private gym for parents and a separate gym for children.