A research team from the School of Public Health at the LKS Faculty of Medicine, the University of Hong Kong (HKUMed), has found that brisk interval walking performed once a week can significantly improve body fat reduction and cardiorespiratory fitness in adults with central obesity, comparable to exercising three times a week – the traditional recommendation for exercise frequency. The study provides strong scientific evidence supporting the therapeutic use of once-weekly brisk interval walking as a convenient exercise approach for adults with central obesity, particularly for those with time constraints. The findings were published in Nature Communications.
A practical, evidence-based exercise approach to combat excess adiposity
Obesity is a common chronic condition characterised by excessive fat accumulation that impairs health. Excess adiposity, particularly when deposited centrally around the abdomen, is linked to negative health outcomes, including cardiovascular disease, metabolic disorders, and increased mortality risk. While regular exercise provides comprehensive health benefits and is integral to obesity management, sustained physical activity remains insufficient, especially for individuals with obesity.
Interval training involves alternating periods of vigorous exercise with lower-intensity active recovery exercise. It is an effective, time-efficient approach for reducing total body and visceral adiposity compared to traditional continuous moderate-intensity training. However, standard exercise guidelines typically recommend interval training three days per week, which may not be practical for individuals with time constraints and limited access to exercise facilities. While previous studies found that the ‘weekend warrior’ exercise pattern, which condenses weekly exercise into one to two days, to have positive effects, there has been limited scientific evidence on the efficacy of interval training performed in this pattern.
Professor Parco Siu Ming-fai, Professor and Head of Division of Kinesiology at the School of Public Health, HKUMed, emphasised the importance of validating whether once-weekly interval training can be as effective as the traditional thrice-weekly regimen, thus offering a practical, evidence-based alternative.
Less frequent, similar efficacy
Between September 2021 and September 2024, HKUMed researchers conducted a rigorous trial in Hong Kong involving 315 Chinese adults aged 18 or older who were overweight and had central obesity. The participants were randomly assigned to one of three groups: a once-weekly interval training group, a thrice-weekly interval training group or a control group.
The control group attended a 2.5-hour health education session every two weeks over a four-month period. The interval training groups performed a total of 75 minutes of interval training per week, either in a single session or divided into three sessions. The participants’ body fat mass was measured using dual-energy X-ray absorptiometry at three assessment points: before the intervention (baseline), at 16 weeks (post-intervention), and at 32 weeks (four-month post-intervention follow-up).
The trial results revealed that at the 16-week assessment, both the once-weekly and thrice-weekly interval training programmes similarly reduced excess adiposity, as measured by total body fat mass, fat percentage and waist circumference, and improved cardiorespiratory fitness compared to the control group.
‘While thrice-weekly interval training remains a commonly recommended approach for the therapeutic management of excess adiposity, our findings show that once-weekly interval training offers similar benefits and represents a practical exercise strategy,’ said Professor Siu. ‘For many adults with central obesity who struggle to balance work, study, family and other commitments, time constraints are a primary barrier to exercising multiple days per week.’
‘Instead of relying solely on high-frequency exercise prescriptions, once-weekly interval training can be considered a feasible and effective alternative,’ added Professor Siu.
KUMed study finds that, with the same total workout time, weekly brisk interval walking improves fat loss and heart fitness in adults with obesity, comparable to exercising three times a week – the traditional recommendation for exercise frequency.
Professor Parco Siu Ming-fai (centre) said that while thrice-weekly interval training is a commonly recommended approach for treating obesity, the study shows that once-weekly interval training with the same total workout time offers similar benefits and is an effective alternative for busy people.
With the rapid growth of Hong Kong’s logistics and delivery services, frontline movers and delivery workers have to cope with physically demanding labour over long periods of time. The United Nations University Hub on Humanitarian Innovation and Technology at Lingnan University (UNU Hub at Lingnan University), the first UNU Hub in Asia and jointly established by Lingnan University and the United Nations University (UNU), recently developed the “IntuCREW – Intelligent Power Assist System”, an AI-powered smart trolley solution that upgrades conventional handcarts into intelligent, power-assisted transport platforms. The system can reduce the pushing effort required to move loads of about 200 kilograms by up to 90 per cent, a force comparable to pushing a 20-kilogram load, significantly easing the physical strain on logistics and delivery workers.
The AI smart trolley integrates advanced Edge AI and haptic sensing technology, enabling the trolley to collect data and process calculations instantly without requiring an internet connection. By detecting the user’s pushing force and direction, the built-in electric drive acts as a mechanical power assist, automatically providing corresponding support. Users need only push, and the system immediately increases the force to move heavy loads forward.
Experimental testing has shown that the AI smart trolley can lessen pushing effort by up to 90 per cent, even on slopes, around corners, and in narrow passageways, while maintaining smooth and stable movement, largely overcoming the difficulties of transporting heavy goods. Built on the design concept of “the greater the pushing force, the greater the reduction in effort”, the system can further reduce the required pushing force by approximately 96.4 per cent when users push the trolley uphill on a 15-degree slope. In addition, the system is equipped with a safety braking mechanism that activates immediately when the handle is released, reducing the risk of the trolley surging forward or sliding backward.
Prof Albert Ko, Founding Director of the UNU Hub at Lingnan University, said that the concept behind the AI smart trolley derives from another Lingnan University innovation originally designed for conventional wheelchairs, the “CREW Intelligent Wheelchair Control System”. Through AI algorithm enhancement and increased load-bearing capability, the technology has evolved into the “IntuCREW – Intelligent Power Assist System” for industrial and logistics applications, representing a cross-sector breakthrough, and extending technology initially designed to assist elderly mobility and relieve caregivers’ physical burden to commercial and industrial use.
Prof Ko said, “Hong Kong has a massive logistics and retail delivery market, where labour costs and physically intensive work have always been major industry challenges. The breakthrough of this technology lies in combining artificial intelligence with haptic sensing technology to create an AI-powered assistive system capable of understanding human pushing behaviour and providing instant power assistance. This addresses pain points in logistics and delivery work by considerably reducing the physical exertion necessary, while improving efficiency and safety. The system has strong potential for application in warehouse management, delivery logistics, hotel services, and retail restocking, and not only demonstrates the wider possibilities of AI technology across different sectors and user groups, but also the considerable opportunities for commercialisation.”
The AI smart trolley has now entered its field-testing stage in Hong Kong, where self-employed delivery workers, warehouse operators, and logistics practitioners, have been recruited, and the project team is collecting usage data and feedback from different working environments to optimise the design and AI algorithms, while also seeking collaboration with logistics and technology companies for commercialisation and large-scale application.
Mr Yim, a self-employed logistics worker participating in the trial, said that using the AI smart trolley when transporting heavy goods during long working hours greatly relieves the strain on his waist and arms reducing fatigue, and improving work sustainability.
Prof Ko added that the AI smart trolley reflects the Hub’s human-centred technology approach, integrating artificial intelligence, engineering design, and social needs to develop practical innovation solutions. The Hub has already developed a number of award-winning humanitarian technology projects, including the mini air purifier designed to improve the living conditions of low-income families, and infant incubators for remote regions. The UNU Hub at Lingnan University will continue to promote research and development in humanitarian innovation and technology, and to explore the practical potential of AI in society, with the aim of improving the working and living conditions of different communities through technology.
The UNU Hub at Lingnan University has developed an AI smart trolley capable of reducing pushing force by up to 90 per cent
The AI smart trolley significantly eases the physical burden on logistics and delivery workers
Prof Albert Ko, Founding Director of the UNU Hub at Lingnan University
Mr Yim, a self-employed logistics worker participating in the trial, using the AI smart trolley
The AI smart trolley in operation
