Strength Specialist Reveals 2 Simple Reasons Your VO2 Max Isn't Improving
If it feels like your VO2 max won't improve no matter how hard you push, it's time to look at the bigger picture. VO2 max, which measures the maximum amount of oxygen your body can utilize during intense exercise, naturally trends downward with age. But what often gets fully blamed on aging really boils down to a gap in the right kind of training stimulus and inconsistent recovery habits.
"As we age, it's normal to see changes in things like cardiovascular output, muscle mass, strength, and mobility," says Scott Brown, vice president of fitness at Orangetheory. "But the body remains highly adaptable. We see this every day across Orangetheory. When you apply a structured, balanced, and progressive stimulus across multiple energy systems, you can significantly slow that decline and, in many cases, continue to improve VO2 max well into your 40s, 50s, 60s, and beyond."
And if training is the stimulus, recovery is where the adaptation happens. The focus, Brown says, should be on repeatable quality, enough intensity to challenge your aerobic threshold, paired with enough recovery to show up again and make progress. After 40, such balance becomes a non-negotiable. Read on to learn how you can address both sides of the coin and, in turn, improve your VO2 max.
Why Isn't My VO2 Max Increasing?
Training Imbalances
Some guys are total cardio junkies, while others live and day by heavy lifts and completely avoid cardio. But if your goal is to improve VO2 max, the biggest gains tend to happen when you combine the two into your weekly workout routine.
Regular cardio is important for building your aerobic base, and interval training should almost always be part of that plan. Intervals provide a time-efficient way to stress the cardiovascular system, and research has found that even relatively short HIIT protocols can improve VO2 max. Consider adding structured interval training two to four times a week for best results.
And though VO2 max is primarily driven by aerobic training, strength training still plays a meaningful support role. Research has even found that in older adults, resistance training alone can produce modest improvements in VO2 maxand other related fitness outcomes.
"Strength training also improves the ability to generate and sustain force, which can make your aerobic work more effective," Brown explains. "You're simply able to hold better mechanics and higher work outputs with less 'energy leaks.'"
Poor Recovery
You may have been able to get away with skimping on recovery efforts as a young buck, but that won't fly these days. Giving your body adequate recovery time plays a major role in improving your VO2 max and building overall performance capacity. A solid rule of thumb is that you should finish most weeks feeling like you could do one more session, not like you need a whole week off, according to Brown.
"Sleep is more critical than I see people give it credit, because it's when your body restores tissue, recalibrates the nervous system, and supports the hormonal environment that helps you respond to training," Brown says. "When sleep is short or inconsistent, performance drops and hard efforts often feel harder and become less productive."
Prioritize high-quality sleep, rest days, and low-impact exercise like walking on a consistent basis.
Related: Personal Trainer Reveals the Weekly Workout Split Proven to Boost VO2 Max for Men Over 40
This story was originally published by Men's Journal on Apr 29, 2026, where it first appeared in the Health & Fitness section. Add Men's Journal as a Preferred Source by clicking here.
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This story was originally published April 29, 2026 at 4:08 PM.