Prediabetes is the quiet warning zone between normal metabolism and full-blown type 2 diabetes. Characterised by fasting glucose between 5.6 and 6.9 mmol/L, impaired glucose tolerance, or glycated haemoglobin between 5.7% and 6.4%, it progresses to overt diabetes at a rate of roughly 5% to 10% per year. Yet that trajectory is not fixed: landmark lifestyle interventions have cut diabetes incidence by up to 58%. With an estimated 537 million adults worldwide now living with diabetes and projections reaching 783 million by 2045, finding accessible, sustainable forms of exercise for the prediabetic population has become a global priority.

The trial, conducted at the Health Management Center of Wuxi Hospital of Traditional Chinese Medicine in Jiangsu Province between July and December 2024, enrolled 62 community-dwelling adults aged 45 and older. Participants were randomly assigned in equal measure to one of three groups: a control group receiving standard lifestyle counselling, a Traditional Chinese Exercise group practising Baduanjin, and a Kuanle Equipment Exercise group using purpose-built resistance and aerobic machines. The researchers measured fasting plasma glucose, two-hour oral glucose tolerance, HbA1c and serum 25-hydroxyvitamin D3 at baseline and again at week twelve, using validated laboratory methods with tight quality control.

The Baduanjin protocol was faithfully classical: three 45-minute supervised sessions per week, each comprising a warm-up, thirty minutes covering three cycles of the eight standardised movements, and a cool-down. The equipment group matched the frequency and duration but followed a circuit of leg press, chest press, rowing and stationary cycling at 60% to 70% of heart rate reserve, supervised by ACSM-certified specialists. Adherence was defined as completing at least 80% of the 36 scheduled sessions, and remarkably, all 62 participants finished the study with complete data, a 100% retention rate the authors attribute to monthly phone follow-ups, weekly reminders and flexible scheduling.

The metabolic results were unambiguous. Both exercise groups showed significant improvements over control in every primary glycaemic measure after adjustment for baseline values. Fasting glucose fell from 6.4 to 5.8 mmol/L in the Baduanjin group and from 6.6 to 5.6 mmol/L in the equipment group, while the control group barely moved. Two-hour glucose tolerance improved by 14.6% in the traditional exercise group and 21.2% in the equipment group. HbA1c, the three-month average of blood sugar, dropped from 6.0% to 5.6% with Baduanjin and from 6.2% to 5.4% with machines, whereas controls saw only a trivial decline.

Crucially, however, the direct head-to-head comparison between the two exercise modalities did not reach statistical significance for any primary outcome, with p-values ranging from 0.071 to 0.089. The equipment group posted numerically larger mean changes, which is biologically plausible given its combination of aerobic and resistance training, but the authors are careful to frame this as descriptive and hypothesis-generating rather than proof of superiority. The trial was also underpowered: recruitment constraints limited enrollment to 62 participants instead of the planned 90, leaving the study able to detect only large effects in direct comparisons.

The vitamin D findings may prove the most talked-about result. Every single participant entered the study deficient, with a mean baseline 25(OH)D3 of roughly 21.5 nmol/L, far below the 50 nmol/L sufficiency threshold. After twelve weeks, levels surged by 60.6% in the Baduanjin group and 81.9% in the equipment group, while controls rose only marginally. Because all exercise sessions were conducted indoors, differential sunlight exposure cannot explain the increase. The authors speculate that exercise-induced metabolic adaptations, such as reduced sequestration of vitamin D in adipose tissue as fat mass declined, or altered hepatic hydroxylation, may be responsible, though they emphasise these mechanisms remain speculative without direct assays.

An exploratory correlation analysis added a tantalising but cautious footnote: across the full cohort, within-person increases in 25(OH)D3 were inversely associated with changes in two-hour glucose tolerance after adjustment for age, sex, baseline BMI and treatment group, but not with fasting glucose, HbA1c or triglycerides. The researchers stress that these secondary analyses, based on a small sample, cannot establish vitamin D as a mediator of the glycaemic benefits. Notably, even after substantial gains, mean vitamin D concentrations in both exercise groups remained below sufficiency, suggesting that exercise alone cannot replace supplementation, particularly in winter or for those with limited sun exposure.

Beyond glucose and vitamin D, both interventions improved body composition and blood lipids. Triglycerides fell by 15% with Baduanjin and 20% with equipment exercise, LDL cholesterol dropped by roughly 10% to 14%, and skeletal muscle mass increased in both groups, while BMI and body fat percentage declined significantly compared with control. Safety was excellent: only minor, transient musculoskeletal complaints occurred, resolving within a week, and no hypoglycaemic events were recorded during the entire study period.

The trial carries important caveats. Nearly 89% of participants were female, limiting generalisability to men; dietary vitamin D intake, clothing coverage, sunscreen use and seasonal variation were not systematically measured during a study spanning July to December; the trial was single-centre and not prospectively registered in a public registry; and the duration of prediabetes was not recorded. Still, the practical message stands: for middle-aged and older adults hovering on the edge of diabetes, a culturally familiar, low-impact practice like Baduanjin offers measurable metabolic benefits comparable, within the limits of this study, to standardised gym-based training. Larger, longer, prospectively registered trials that track sunlight and dietary vitamin D will be needed to confirm whether the vitamin D surge is a genuine exercise effect, and whether the numerical edge of machine-based training hardens into proven superiority.

Subject of Research: Effects of traditional Chinese exercise versus equipment-based exercise on glycaemic control and vitamin D levels in adults with prediabetes

Article Title: Comparison of Traditional Chinese Exercise and Equipment‐Based Exercise on Glycaemic Control and Vitamin D Levels in Middle‐Aged and Elderly Patients With Prediabetes: A Randomised Controlled Trial

Article References: Lingzhi, X., Chunhua, Z., Wu, L., Jiejin, D., & Yimin, Y. (2026). Comparison of Traditional Chinese Exercise and Equipment‐Based Exercise on Glycaemic Control and Vitamin D Levels in Middle‐Aged and Elderly Patients With Prediabetes: A Randomised Controlled Trial. Endocrinology, Diabetes & Metabolism, 9(5), Article e70326. https://doi.org/10.1002/edm2.70326

Image Credits: AI Generated

DOI: 10.1002/edm2.70326

Keywords: prediabetes, type 2 diabetes, Baduanjin, Qigong, exercise, vitamin D, HbA1c, glycaemic control, randomised controlled trial, insulin resistance, body composition, traditional Chinese exercise