VO2 max is often referred to as a key marker of fitness. It’s the measure of the maximal amount of oxygen your cells can take in and use during exercise.
Because VO2 max is so closely tied to running performance, you might wonder if there are any other avenues—beyond VO2 max running workouts—to boosting your stats.
One method to consider: strength training. Lifting has a spot in many runners’ schedules, and you’ve probably heard about the plethora of benefits of picking up weights. So it’s logical to ask whether your time spent lifting will also nudge your cardio fitness ceiling higher.
To get the details, we consulted an exercise physiologist to explain the link between strength and your VO2 max. What we found may surprise you.
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How Strength Training Affects VO2 Max
“Historically, people think about strength training as bodybuilding—big, heavily weighted compound motions,” says Kate Baird, CSCS, running and metabolic testing coordinator and exercise physiologist at the Hospital for Special Surgery in New York City. But strength training can also include lighter-weight circuit-based sessions.
When it comes to physiological changes in the body, those distinctions matter.
If we’re talking about traditional lifting—heavy weights, explosive movements, and substantial rest between sets—the effects on VO2 max are quite limited, largely because of how the heart adapts to this type of strength training, Baird says.
During high-intensity aerobic-focused exercises like running, the heart undergoes what’s known as eccentric remodeling, explains Baird. The chambers—specifically the left ventricle—expand and become more stretchy, allowing them to fill with more blood. This leads to an increase in stroke volume or how much blood the heart pumps out with each beat. “This is important because we know that the number-one thing that leads to an increase in VO2 max is an increase in stroke volume,” Baird continues.
Heavy strength training stresses the cardiovascular system differently. Blood pressure and heart rate elevate under short, intense bursts of effort, but the heart adapts concentrically. The heart gets better at handling sudden, heavy workloads while still pumping blood efficiently. This type of adaptation doesn’t substantially increase stroke volume though, and therefore doesn’t significantly affect VO2 max, Baird says.
However, when it comes to more aerobic-focused strength-building strategies—the lighter weights, higher reps, shorter rest periods approach—there is some room for VO2 max improvement.
If a sedentary person starts doing 30 minutes of continuous circuit-style strength training three times per week, “they’re absolutely going to see their VO2 max change within a couple of months,” Baird says. But, that’s largely because they’re going from doing nothing to just doing something. This type of person has no fitness foundation, so virtually any activity at all would elevate their VO2 max level. For example, a 2013 study shows that in order to see significant VO2 max gains from resistance training, a subject’s starting VO2 max must be lower than the average for their age group.
Runners won’t necessarily see the same increase. “If you take a runner and give them a strength program and that’s the only thing that’s different [from their normal running routine], it is very unlikely that they are going to improve their VO2 max by adding this,” Baird explains.
In other words, if you’re already exercising your aerobic system with VO2 max workouts and regular mileage, your heart is already adapting in the ways that influence VO2 max. “You have to work really hard to move [VO2 max] up when you are well trained,” Baird says. “That’s why everyone isn’t walking around with a VO2 max of 70.”
Improved capillary density, oxygen delivery, and oxygen extraction at the muscle (your muscle’s ability to efficiently use the oxygen delivered to it) also boost VO2 max, but these adaptations don’t shift dramatically by adding a few days of lifting to an established running routine, Baird says. “For really fit people, the only [VO2 max booster] that’s really going to get better, at a certain point, is stroke volume,” explains Baird. And, as previously mentioned, increasing stroke volume requires high-intensity aerobic work.
The bottom line: Strength training isn’t a shortcut to a higher VO2 max, especially for established runners, but it can definitely help those who are just starting an exercise routine. What’s important to remember, though: The benefits of strength training lie in other fitness metrics, making it crucial for runners to keep on their schedules.
Why Strength Training Still Matters for Run Performance
“If you put a nice engine in a crappy car, you’re not going to get very far,” Baird says.
Strength training builds the musculoskeletal frame that supports your strong aerobic engine. It helps address biomechanical inefficiencies and shores up weak links that can lead to injury. Leave strength training out of the picture, and you expose yourself to injury risk and the inability to access your full endurance potential.
What’s more: Research shows that strength training boosts running economy, which is how efficiently your body uses oxygen at a given running speed, and it’s arguably more important than VO2 max for long-distance race performance.
Heavy lifting also improves short-term force generation, which is perfect for the demands of fast running. And plyometric training leads to greater energy storage and more springiness, boosting running efficiency overall.
So, while strength training may not significantly boost your oxygen-processing ceiling, it can elevate your oxygen-usage efficiency while helping you stay strong and injury-proof throughout your training. And in the long run, that combination can lead you to your next PR.
Matt Rudisill is an Associate Service Editor with the Hearst Enthusiast Group. A Nittany Lion through-and-through, Matt graduated from PSU in 2022 with a degree in journalism and worked in communications for the university’s athletic department for the past three years as the main contact and photographer for its nationally-ranked cross country and track & field teams. Matt was also heavily involved in communications efforts for the Penn State football team’s 2024 College Football Playoff run as well as the Nittany Lion men’s basketball team’s 2023 NCAA Tournament appearance. In his role with Hearst’s Enthusiast Group, Matt contributes to both Runner’s World and Bicycling magazines, creating service content to benefit runners and cyclists of all ages. When he’s not out jogging, Matt can be found tweeting bad takes about the Phillies or watching movies.
