Can weight training protect against type 2 diabetes better than running?

In a quiet Virginia laboratory, scientists set mice an unusual task: to earn their food, they had to lift a lid.

What started as an unconventional experiment involving miniature “mouse gyms” has raised an important question for people: might weight training offer better protection against type 2 diabetes than running and other forms of cardio exercise?

Why blood sugar matters to scientists

Blood sugar, also called blood glucose, provides energy for our cells. It largely comes from food, particularly carbohydrates. After digestion, glucose enters the bloodstream, but it needs the hormone insulin to get into cells, where it is used as fuel.

If this carefully balanced process stops working properly, blood sugar may remain too high for too long. In healthy adults, fasting blood sugar is generally between around 0.70 and 1.10 grams per litre of blood. Levels above this range signal hyperglycaemia, which can eventually lead to type 2 diabetes if it continues.

With type 2 diabetes, the body either fails to make enough insulin or its cells no longer respond to insulin effectively, a condition called insulin resistance. Carrying excess weight, being inactive and genetic factors can all increase the likelihood of this happening.

Exercise is one of the most reliable tools doctors use to improve blood sugar control and reduce diabetes risk.

Cardio activities including walking, running and cycling have traditionally received most of the attention. They use calories, benefit the heart and improve insulin sensitivity. However, strength training has also been building a compelling case, and a new study in mice indicates that it may warrant much greater focus.

The first “weightlifting” mice

Creating a rodent model for strength training

Researchers from Virginia Tech, working with the University of Virginia, wanted to investigate a deceptively straightforward question: when resistance training is compared with endurance training, which produces greater improvements in blood sugar control?

To find out, the scientists developed what they call the first mouse model of weightlifting. Rather than using a running wheel, the mice lived in cages with their food beneath a weighted lid. Whenever a mouse wanted to eat, it needed to push the lid upwards against resistance that the researchers could progressively increase.

The arrangement replicated progressive resistance training in people, in which weights are raised over time to continue challenging the muscles. In practice, the mice became miniature powerlifters.

A separate group made up the “endurance” team. These mice could use a running wheel, allowing voluntary cardio-style activity comparable to jogging or steady cycling in humans.

In addition to the exercising groups, the researchers monitored two sedentary groups: one fed a standard diet and another given a high-fat diet designed to reflect a lifestyle linked to weight gain and metabolic problems.

Eight weeks, four groups and striking findings

Measures tracked by the researchers

Over eight weeks, the team assessed several health measures in the mice:

• Body weight and total body composition
• The quantity and distribution of body fat, including abdominal fat
• Strength and physical performance
• Heart and muscle function
• Blood sugar regulation and insulin response

They focused especially on the ability of the animals’ muscles to respond to insulin. More effective insulin signalling in muscle tissue generally enables the body to remove glucose from the bloodstream more efficiently, helping to maintain blood sugar within a healthier range.

Weight training outperforms running for blood sugar

Each form of exercise produced obvious benefits. Relative to inactive mice, both the running and weightlifting groups had lower levels of abdominal and subcutaneous fat, alongside improved blood sugar control.

The surprise came when the researchers compared the two active groups: resistance training matched or outperformed running on key markers of glucose regulation.

The team reported that the mice using the strength-training set-up experienced particularly strong improvements in insulin signalling within skeletal muscle. This appeared to result in more efficient blood sugar control, indicating that resistance exercise could have antidiabetic effects that are at least as powerful as, and potentially stronger than, endurance exercise on its own.

Published on 30 October 2025 in the Journal of Sport and Health Science, the findings add to the growing case for placing strength training alongside cardio, rather than below it, in guidance on preventing diabetes.

What this may mean for type 2 diabetes

This was a mouse study rather than a human one, so its results cannot be directly applied to people. Nevertheless, the changes observed in the animals’ muscle cells appear highly relevant to human disease.

According to International Diabetes Federation estimates, type 2 diabetes affects approximately one in nine adults globally. Many people who are at risk are already told to “be more active”, but that advice is often not specific.

By showing how resistance training changes insulin-related pathways in muscle, the study hints at new drug targets and clearer exercise prescriptions.

If researchers can identify the precise molecular changes that take place in trained muscle, pharmaceutical teams may be able to create medicines that reproduce some of these effects. Meanwhile, healthcare professionals may be more confident in recommending strength work not merely as an extra, but as a central element of prevention and management plans.

Cardio vs weights: is there really a choice?

For anyone considering the practical implications, the research does not suggest that running has no value. On the contrary, endurance-trained mice also reduced body fat and gained better blood sugar control. Cardiovascular exercise further benefits heart function, lung capacity and mental health.

Instead, the findings indicate that weight training offers a distinct advantage, particularly through the way it reshapes muscle tissue and increases insulin sensitivity.

Type of exercise	Main focus	Key benefits for blood sugar
Endurance (running, cycling)	Heart, lungs, calorie burn	Improves insulin sensitivity and helps reduce body fat
Resistance (weights, bands, bodyweight)	Muscle strength, power, mass	Enhances insulin signalling in muscle and increases glucose uptake

In everyday life, the strongest outcomes often come from combining the two exercise types. Brief runs or brisk walks to support heart health, together with two or three weekly strength sessions for muscle and metabolic control, can form a powerful combination.

What strength training can involve for ordinary people

Strength training need not involve a daunting weights area or heavy barbells. Its basic principle is straightforward: muscles need to work against resistance in order to adapt.

That resistance can come from:

• Your own body weight, such as squats, push-ups, lunges and planks
• Resistance bands used at home
• Dumbbells or kettlebells, whether in a gym or living room
• Machines that support the movement for beginners

For somebody worried about blood sugar, a standard starting approach could be full-body strength sessions on two non-consecutive days each week. A session might include 6–8 exercises for the major muscle groups, using one to three sets of 8–12 repetitions according to fitness level.

As strength develops, the resistance can be raised over time, much like the mice that lifted increasingly heavy lids to access their food.

Key terms for understanding the science

Several scientific concepts are central to this research. Knowing what they mean makes the mouse findings more meaningful in day-to-day terms.

• Insulin sensitivity: the extent to which the body’s cells respond efficiently to insulin. Greater sensitivity means cells require less insulin to take up the same amount of glucose.
• Insulin resistance: a condition in which cells do not respond to insulin’s signal. The pancreas must release more insulin to control blood sugar, and this pressure can contribute to type 2 diabetes over time.
• Skeletal muscle: muscles connected to the bones that make movement possible. They serve as a major glucose “sink”, taking glucose from the blood both during activity and as they adapt to training.

By altering the way skeletal muscle deals with insulin and glucose, strength training effectively improves one of the body’s key systems for controlling rises and falls in blood sugar.

Where the research could go next

This mouse model creates opportunities for further research. Scientists can now alter diet, training volume or particular genes to establish which combinations deliver the largest improvements in blood sugar control. They can also assess potential medicines alongside exercise to determine whether the effects are cumulative or overlapping.

For those with prediabetes or a strong family history of type 2 diabetes, this evidence reinforces a clear practical message: gaining and retaining muscle is not only about looks or strength. It may become a fundamental part of safeguarding long-term metabolic health, one exercise session at a time.