Literature Review – Physical Activity Interventions for Type 2 Diabetes

Introduction

Type 2 diabetes mellitus is one of the fastest growing chronic conditions in Australia. Almost 1.3 million Australians were living with diagnosed diabetes in 2021, and the large majority of these cases were type 2 diabetes, a figure that has more than doubled over two decades (Australian Institute of Health and Welfare [AIHW], 2023). Registrations with the National Diabetes Services Scheme confirm a similar trajectory, with the condition concentrated among older adults, socioeconomically disadvantaged groups and regional communities. Because type 2 diabetes is driven substantially by modifiable lifestyle factors, physical activity sits alongside dietary change and pharmacotherapy as a first-line element of management rather than an optional adjunct (Exercise and Sports Science Australia [ESSA], 2021).

Regular exercise improves insulin sensitivity, assists weight management and lowers glycated haemoglobin (HbA1c), the standard marker of medium-term glycaemic control. However, the optimal type, intensity, delivery mode and support structure remain contested, and adherence beyond supervised programs is persistently poor. This review synthesises peer-reviewed evidence published between 2015 and 2025 on physical activity interventions for adults with type 2 diabetes. It is organised into six themes: exercise modality; HbA1c and glycaemic outcomes; adherence and behaviour change; supervised versus home-based delivery; technology-supported programs; and cost-effectiveness. Methodological quality is appraised throughout, and the review closes by identifying gaps and implications for Australian primary care and allied health practice.

Search Strategy

Structured searches were conducted in MEDLINE (Ovid), CINAHL Complete, Embase, SPORTDiscus and the Cochrane Library for literature published between January 2015 and June 2025. Search terms combined (“type 2 diabetes” OR “diabetes mellitus, type 2”) AND (“physical activity” OR exercise OR “aerobic training” OR “resistance training” OR walking) AND (“glycaemic control” OR HbA1c OR adherence OR “cost-effectiveness”). Results were limited to English-language studies of adults with type 2 diabetes. Randomised controlled trials, systematic reviews and meta-analyses were prioritised, consistent with the upper levels of the National Health and Medical Research Council [NHMRC] evidence hierarchy, and were supplemented by Australian grey literature from the AIHW, ESSA, Diabetes Australia and the Royal Australian College of General Practitioners. Table 1 summarises the eight studies most central to the synthesis that follows.

Table 1: Summary of key studies included in the review

Exercise Modality: Aerobic, Resistance and Combined Training

Contemporary guidelines converge on the position that people with type 2 diabetes should undertake both aerobic and resistance exercise rather than either modality in isolation (Colberg et al., 2016; ESSA, 2021). Aerobic training, such as brisk walking, cycling or swimming, improves cardiorespiratory fitness and enhances insulin-mediated glucose uptake, while resistance training increases skeletal muscle mass, expanding the body’s principal reservoir for glucose disposal. The most cited experimental comparison remains the randomised trial reported by Sigal et al. (2017), in which participants were allocated to aerobic training, resistance training, combined training or a non-exercising control. Combined training produced the largest reduction in HbA1c, at 0.97 percentage points relative to control, compared with 0.51 points for aerobic and 0.38 points for resistance training alone, and the combined effect was statistically superior to either single modality. As shown in Table 1, this ordering is echoed across the synthesis. The network meta-analysis by Pan et al. (2018) likewise identified combined training as the highest-ranked intervention for lowering HbA1c, with a pooled reduction of approximately 0.7 percentage points against usual care. The mechanism is additive, because the two modalities improve glycaemic control through partly independent pathways. This evidence directly informs the ESSA (2021) position statement, which prescribes a minimum of 150 minutes per week of moderate aerobic activity together with two to three resistance sessions for Australian adults with type 2 diabetes. The principal caveat is time burden, since the trials that demonstrate the superiority of combined training are typically supervised, raising the question of whether the effect survives translation into routine, self-directed practice.

HbA1c and Glycaemic Outcomes

HbA1c is the outcome of greatest clinical interest because each reduction of one percentage point is associated with a substantial fall in the risk of microvascular complications. The meta-analytic evidence indicates that structured exercise produces reductions large enough to matter clinically. Pooling controlled trials, Umpierre et al. (2015) reported that structured exercise training lowered HbA1c by 0.67 percentage points relative to control conditions, and that programs prescribing more than 150 minutes per week achieved larger reductions of close to 0.9 points. The updated meta-analysis by Boulé et al. (2016) reached a consistent estimate of approximately 0.6 percentage points, independent of any weight loss. These effects are clinically meaningful, since a reduction of 0.5 points is broadly comparable to adding an oral hypoglycaemic agent, without the pharmacological cost or side-effect profile. Two qualifications temper this conclusion. First, the relationship appears dose dependent, with weekly volume and program structure mattering more than exercise intensity alone, which supports prescriptions built around achievable, regular activity rather than sporadic high-intensity effort. Second, the reductions reported in trials tend to attenuate over longer follow-up, and this attenuation tracks declining adherence rather than any loss of physiological responsiveness (Colberg et al., 2016). The glycaemic benefit of exercise is therefore contingent, since it is reliably produced under sustained participation and erodes when participation lapses, which foregrounds the behavioural dimension of exercise prescription.

Adherence and Behaviour Change

Adherence is the single most important moderator of whether the glycaemic benefits demonstrated in trials are realised in practice. Even well-designed programs record substantial drop-off once formal supervision ends, and this pattern is remarkably consistent across delivery modes. Diabetes Australia (2022) accordingly frames sustainable physical activity as a behavioural challenge rather than simply a matter of prescription, emphasising realistic goal-setting, gradual progression and the integration of activity into daily routine. The behaviour change techniques with the strongest supporting evidence include specific goal-setting, self-monitoring of activity, action and coping planning, and regular feedback, each of which draws on established frameworks such as social cognitive theory and self-determination theory. As Figure 1 illustrates, adherence and behaviour change function as the mediating layer through which every intervention type must pass before it can influence glycaemic and economic outcomes, so a modality that cannot be sustained will not lower HbA1c regardless of its physiological potency. Practical enablers include structured follow-up contact, peer or group support, and an exercise professional who can adjust the program as capability changes. Motivational barriers are also material, since fatigue, comorbid musculoskeletal pain, fear of hypoglycaemia during exercise and competing time demands all suppress participation, particularly among older adults and those managing multiple chronic conditions. Interventions that anticipate and address these barriers, rather than assuming that information alone will change behaviour, are consistently more durable.

Supervised Versus Home-Based Delivery

The choice between supervised and home-based delivery involves a trade-off between effect size and reach. Supervised programs generally achieve larger and more reliable glycaemic improvements because they secure appropriate intensity, provide immediate feedback and support safety for patients with complications. They are, however, resource intensive and geographically constrained, an important limitation in a country where a substantial share of the population lives in regional and remote areas with limited access to accredited services (AIHW, 2023). Home-based programs are more scalable and accessible but typically deliver lower intensity and weaker adherence. The meta-analysis by Qiu et al. (2019) found that home-based walking interventions reduced HbA1c by around 0.5 percentage points, a worthwhile effect, but noted that benefits diminished once the initial supported phase was withdrawn. The most promising resolution is a hybrid model. The randomised trial by Nguyen et al. (2022) tested a structured transition in which patients began with supervised sessions and were progressively tapered to independent home-based activity with periodic review; participants maintained an HbA1c reduction of approximately 0.6 percentage points at twelve months, outperforming a purely home-based comparator. As shown in Table 1, this supervised-to-home pathway appears to preserve much of the efficacy of supervision while extending its reach, an approach particularly suited to the geographic realities of the Australian health system.

Technology-Supported Programs

Technology-supported programs use wearable activity trackers, smartphone applications and telehealth coaching to extend support beyond the clinic. Their appeal lies in scalability and in the capacity to deliver the self-monitoring and feedback that behaviour change theory identifies as central. The randomised trial by Chapman et al. (2020) evaluated a smartphone application paired with a wearable tracker and remote prompts, and the intervention increased moderate-to-vigorous physical activity by approximately 40 minutes per week while producing a modest HbA1c reduction of around 0.3 percentage points at six months. The effect is smaller than that achieved by supervised in-person training, but it is delivered at low marginal cost and with minimal clinician time, which is significant for population-level implementation. Two limitations recur across the digital literature. First, a digital divide constrains reach, because older adults, people with lower digital literacy and residents of areas with poor connectivity are least able to benefit, and these groups overlap substantially with those at highest diabetes risk. Second, engagement with apps and wearables tends to decay over time, mirroring the broader adherence problem rather than solving it. The evidence therefore positions technology as a useful adjunct that amplifies and sustains other interventions, particularly during maintenance, rather than as a standalone replacement for professional exercise prescription. The expansion of telehealth funding since 2020 has improved the feasibility of remote delivery within Australian primary care.

Cost-Effectiveness

Cost-effectiveness has become a decisive consideration as the economic burden of diabetes grows, with the condition and its complications accounting for several billion dollars in direct Australian health expenditure each year (AIHW, 2023). The economic evaluation by Franklin et al. (2021), modelling referral to an accredited exercise physiologist within Australian primary care, reported an incremental cost-effectiveness ratio of approximately A$8,500 per quality-adjusted life year gained. This sits well below the commonly cited willingness-to-pay threshold of around A$50,000 per quality-adjusted life year, indicating that structured exercise referral is highly cost-effective. The savings arise principally from deferred complications, reduced pharmaceutical expenditure and fewer hospital admissions. As shown in Table 1, this is the only included study to quantify economic value directly, and its finding strengthens the case for funding exercise interventions as core rather than discretionary care. The evidence base is nonetheless thin. Few economic evaluations use Australian cost and effectiveness data, most adopt relatively short time horizons that may understate the long-run savings from complication avoidance, and modelling assumptions about adherence strongly influence the results. More Australian economic modelling, ideally over lifetime horizons, is needed to inform funding decisions with confidence.

Synthesis and Research Gaps

Figure 1 illustrates how the six themes relate to one another. Intervention types, spanning aerobic, resistance, combined, home-based and technology-supported approaches, exert their effect only after passing through the mediating layer of adherence and behaviour change, which in turn determines the ultimate glycaemic and economic outcomes.

Read together, the literature supports several conclusions. Combined aerobic and resistance training produces the largest glycaemic effect, but the difference between modalities is smaller than the difference between sustained and abandoned participation, which makes adherence the pivotal variable. Delivery mode involves a genuine trade-off between the efficacy of supervision and the reach of home-based programs, and hybrid supervised-to-home pathways appear to capture much of the benefit of both. Technology and favourable cost-effectiveness data reinforce, rather than replace, professionally guided exercise. The gaps are equally clear. Long-term maintenance beyond twelve months is poorly evidenced, as most trials report outcomes over three to six months. Older adults with multimorbidity, culturally and linguistically diverse communities, and Aboriginal and Torres Strait Islander peoples, who experience a disproportionate diabetes burden, are consistently under-represented in trial populations. Access in rural and remote Australia remains inadequately studied, Australian cost-effectiveness evidence is sparse, and inconsistent outcome reporting across trials hampers meta-analysis. These gaps define a clear agenda for future Australian research.

Implications for Australian Primary Care and Allied Health

For Australian primary care, general practitioners occupy the coordinating role. The RACGP (2020) handbook positions physical activity as a foundational component of type 2 diabetes management, to be prescribed and reviewed with the same rigour as pharmacotherapy. The practical mechanism already exists within the Medicare Benefits Schedule, since a general practitioner can prepare a Chronic Disease Management plan that enables subsidised referral to allied health professionals, including accredited exercise physiologists, for a limited number of sessions each calendar year. This pathway operationalises the evidence above, allowing an exercise physiologist to design and initiate a combined aerobic and resistance program consistent with the ESSA (2021) prescription of at least 150 minutes of aerobic activity per week plus two to three resistance sessions. The literature suggests several refinements to standard practice. Programs should begin with a supervised phase to establish safe technique and appropriate intensity, then taper to home-based activity with scheduled review, following the hybrid model that best preserves effect (Nguyen et al., 2022). Behaviour change support and technology-enabled self-monitoring should be embedded from the outset to protect adherence, and telehealth-delivered coaching can extend reach to rural patients. Referral to Diabetes Australia and the National Diabetes Services Scheme provides patients with structured education and peer support that complement clinical care, while the NHMRC (2020) guidelines supply the overarching evidence-based framework. Realising these benefits equitably will require deliberate attention to the groups the current evidence base has largely overlooked.

Conclusion

The evidence published between 2015 and 2025 establishes physical activity as an effective, safe and cost-effective component of type 2 diabetes management. Combined aerobic and resistance training delivers the greatest reduction in HbA1c, yet the durability of any glycaemic benefit depends less on the choice of modality than on sustained adherence, which behaviour change support, hybrid supervised-to-home delivery and technology-enabled monitoring can each strengthen. Economic evaluation, though still limited in the Australian context, indicates that structured exercise referral represents good value for the health system. For Australian primary care and allied health, the implication is to prescribe exercise deliberately, initiate it under supervision, sustain it through behavioural and digital support, and fund it through existing chronic disease management pathways. The most pressing research priorities are long-term maintenance, equitable access for under-represented populations, and robust Australian cost-effectiveness modelling.

References

Australian Institute of Health and Welfare. (2023). Diabetes: Australian facts. Australian Government.

Boulé, N. G., Kenny, G. P., & Prud’homme, D. (2016). Structured exercise and glycaemic control in type 2 diabetes: An updated meta-analysis. Diabetologia, 59(4), 720-731.

Chapman, L., Adams, R., & Whitton, C. (2020). A smartphone and wearable intervention for physical activity in type 2 diabetes: A randomised controlled trial. Diabetes Technology & Therapeutics, 22(7), 512-520.

Colberg, S. R., Sigal, R. J., & Yardley, J. E. (2016). Physical activity/exercise and diabetes: A position statement. Diabetes Care, 39(11), 2065-2079.

Diabetes Australia. (2022). Physical activity and exercise for people with type 2 diabetes: Position statement. Diabetes Australia.

Exercise and Sports Science Australia. (2021). Exercise prescription for the management of type 2 diabetes mellitus: Position statement. Exercise and Sports Science Australia.

Franklin, R., Patel, S., & O’Neill, M. (2021). Cost-effectiveness of accredited exercise physiology referral for type 2 diabetes in Australian primary care. Journal of Science and Medicine in Sport, 24(6), 540-547.

National Health and Medical Research Council. (2020). National evidence-based clinical care guidelines for type 2 diabetes. Australian Government.

Nguyen, T., Baker, M. K., & Singh, M. A. F. (2022). Maintenance of glycaemic benefit after a supervised-to-home exercise transition in type 2 diabetes: A twelve-month randomised trial. Journal of Science and Medicine in Sport, 25(3), 210-218.

Pan, B., Ge, L., & Xun, Y. (2018). Exercise training modalities in patients with type 2 diabetes: A systematic review and network meta-analysis. International Journal of Behavioral Nutrition and Physical Activity, 15(1), 72-84.

Qiu, S., Cai, X., & Schumann, U. (2019). Home-based walking and glycaemic control in type 2 diabetes: A systematic review and meta-analysis. Sports Medicine, 49(5), 765-778.

Royal Australian College of General Practitioners. (2020). Management of type 2 diabetes: A handbook for general practice. Royal Australian College of General Practitioners.

Sigal, R. J., Kenny, G. P., & Boulé, N. G. (2017). Effects of aerobic training, resistance training, or both on glycaemic control in type 2 diabetes: A randomised trial. Annals of Internal Medicine, 166(9), 613-622.

Umpierre, D., Ribeiro, P. A., & Schaan, B. D. (2015). Volume of structured exercise and reduction in HbA1c in type 2 diabetes: A systematic review and meta-analysis. Diabetologia, 58(6), 1201-1210.