Cardio Before or After Weights? The Answer Might Surprise You

The order of your cardio and strength training workouts probably doesn't matter as much as you think. According to exercise experts, there's such a minimal physiological difference that it mostly comes down to personal preference and your specific fitness goals.

What Does the Science Actually Say?

"The simple answer is it probably doesn't matter," says Luke Carlson, founder and CEO of Discover Strength. "There might be some mechanistic rationale for why it should matter. But, in the studies, we just don't ever see it matter." This finding challenges the common gym wisdom that has sparked countless debates among fitness enthusiasts.

Alex Rothstein, exercise physiologist and coordinator of the Exercise Science program at New York Institute of Technology, agrees. "There's such a minimal difference that I wouldn't argue one versus the other is better," he explains.

When Should You Prioritize One Over the Other?

While the general rule is flexibility, there are specific situations where order might influence your performance. The key principle is simple: start with whatever matters most to your current goals.

If you're training for a specific event like a half marathon, leading with cardio makes sense. "If you do the strength first and then you move into the cardio, you're going to be fatigued from the strength and you're not going to be able to perform that running workout at the same level," Carlson explains. You'll compromise your ability to hit target paces during tempo runs or interval sessions.

The same logic applies in reverse for strength-focused goals. If you're working toward a personal record in lifting, tackle the weight room first to ensure you can perform at your peak capacity.

Why Experts Recommend Separating Your Workouts

Despite the flexibility in timing, both experts agree that splitting cardio and strength training into separate sessions is ideal when possible. The primary concern isn't about muscle building or cardiovascular gains—it's about injury prevention.

Exercise fatigue affects your entire body system, not just the specific muscles you've worked. Even seemingly unrelated activities impact your performance in unexpected ways:

• Nervous System Fatigue: Your central nervous system becomes taxed regardless of which muscles you've targeted, affecting coordination and focus
• Stabilization Compromise: Core and stabilizing muscles work during both cardio and strength training, even when they're not the primary focus
• Form Deterioration: "Fatigue only makes form worse," notes Rothstein. "You're never going to have better form, because you're more fatigued"

A recent 2025 study found that warming up before strength training had an insignificant impact on exercise performance, including strength and endurance measures. This research challenges the traditional belief that cardio serves as an effective warm-up for lifting.

What About Muscle Building Goals?

Here's some encouraging news for those worried about compromising their gains: doing cardio before lifting won't sabotage your muscle-building efforts. Current research shows that building muscle is more about training to failure than hitting a specific number of repetitions.

"If someone wants to use their cardio to feel like they have a sweat and they are warm moving into their strength training, that's fine, but I would never do it for that reason," says Carlson, noting the lack of scientific rationale for cardio as a strength training warm-up.