Want Better Blood Sugar? Science Says Pick Up The Weights
We know that both cardio and strength training are good for us, but when it comes to blood sugar balance and fat loss, one type of workout may pull ahead.
A new preclinical study1 found that resistance training was more effective than running at improving insulin sensitivity and reducing body fat, even when both types of exercise were performed consistently. In other words, if you’re lifting weights, you may be doing your metabolism a major favor.
Here’s what the researchers discovered and what it means for how you structure your workouts.
Running vs. weightlifting, head-to-head
To compare the two exercise types fairly, the research team had to get creative. They built what's essentially a mouse weightlifting gym.
In this setup, mice had to lift a small weighted lid to access food, creating a squat-like movement that mimicked resistance training. The researchers gradually increased the weight over several days, just like progressive strength training in humans. A second group had open access to a running wheel, representing endurance exercise. Both groups were fed a high-fat diet, which is commonly used to simulate obesity and insulin resistance in lab settings.
Over eight weeks, researchers tracked weight, fat distribution, and blood sugar control, along with muscle and heart function. By the end of the study, both exercise groups outperformed their sedentary peers—but the resistance-trained mice stood out.
They had significantly lower visceral and subcutaneous fat, better glucose tolerance, and greater insulin sensitivity—three key markers that determine diabetes risk and metabolic health.
Interestingly, these benefits weren’t simply due to building more muscle or improving athletic performance. The weight-trained mice showed unique changes at the molecular level that enhanced how their muscles responded to insulin.
Why strength training may give your metabolism an edge
While cardio improves heart health and endurance, resistance training triggers a cascade of metabolic adaptations that appear especially powerful for blood sugar regulation.
When you lift weights, your muscles use glucose for fuel, helping to pull excess sugar out of the bloodstream. Over time, this improves how effectively your cells respond to insulin—the hormone that helps shuttle glucose into cells for energy.
These findings align with human studies showing that people who engage in regular strength training have lower HbA1c levels (a long-term marker of blood sugar control), less abdominal fat, and better metabolic flexibility compared to those who rely on cardio alone.
Another advantage is that muscle tissue is metabolically active. The more lean mass you maintain, the more calories your body burns at rest, even when you’re not exercising. That means strength training not only helps balance blood sugar in the moment; it also supports a healthier metabolism long-term.
What this means for your workouts
The takeaway isn’t that you should ditch your morning run. Endurance exercise is still incredibly beneficial for cardiovascular health, mental clarity, and longevity. But if you’re looking to prevent or manage insulin resistance, support fat loss, or improve energy balance, adding regular resistance training to your routine could make a real difference.
Here’s how to get started or optimize what you’re already doing:
- Lift two to three times per week: Aim for full-body sessions that include compound movements, like squats, lunges, deadlifts, rows, and presses. These engage large muscle groups and create the biggest metabolic demand.
- Focus on progressive overload: Gradually increase the resistance, number of sets, or repetitions over time. That progressive challenge is what drives muscle adaptation and metabolic improvement.
- Mix modalities for balance: For most people, the ideal combination is a blend of resistance and endurance training. Cardio keeps your heart and mitochondria strong, while strength work builds the muscle that powers your metabolism.
- Prioritize recovery and protein: Muscle repair happens during rest—and it requires adequate protein. Aim for a high-quality source at each meal to support muscle growth and insulin sensitivity.
The takeaway
Both cardio and strength training have their place, but if your goal is to build resilience from the inside out, pick up the weights. Whether you’re squatting in your living room or pressing dumbbells at the gym, you’re not just building muscle; you’re improving insulin sensitivity, balancing blood sugar, and protecting your long-term health.
And while this study was conducted in mice, its findings align with human research showing that resistance exercise powerfully supports glucose regulation and long-term metabolic health.
