Why Most Boxers Are Conditioning the Wrong Way — And How to Fix It

For decades, boxing conditioning has been stuck in tradition. Long slow road runs, hours of Zone 2 cardio, and the belief that this is the best way to build endurance have been passed down from coach to fighter like an unbreakable rule. But here’s the truth: if you’re already a well-trained boxer, these methods might be giving you far less return than you think.

Most boxers follow a familiar pattern: plenty of steady-pace running out of camp, then ramping up the intensity with sprints and intervals closer to fight night. While this approach isn’t inherently “wrong,” new research and practical experience with fighters suggest there’s a more time-efficient way to get better results — and spend more time on the thing that really matters: boxing skills.

The common argument for all that low-intensity work is that it “builds an aerobic base.” That’s true — up to a point. But here’s the problem: in boxing, the bottleneck for endurance usually isn’t your heart and lungs (central adaptations), it’s your muscles’ ability to actually use the oxygen you deliver (peripheral adaptations).

Studies show that most trained boxers already have a solid VO₂ max — often in the 49–55 range — without touching the sky-high numbers of elite marathoners or cyclists. Yet, they can still perform at an incredibly high level. This means your central systems (heart and lungs) probably aren't the limiting factor. Instead, it’s mitochondrial efficiency and content within the muscles that matter most.

Yes, Zone 2 work can improve these mitochondrial adaptations — but it’s slow, time-consuming, and may not even work if you’re already well trained. A huge review of over 6,000 participants found that Sprint Interval Training (SIT) was nearly four times more efficient at producing mitochondrial adaptations than Zone 2 cardio. And in well-trained athletes (VO₂ max around 55), only SIT actually moved the needle.

In other words, if you’ve been consistently boxing three to four times a week for a couple of years, your body has already adapted to low-intensity work. Adding more of it is unlikely to create further gains — and might just pile on unnecessary fatigue.

Plus, much of your regular boxing training — pad work, technical sparring, drills, even shadowboxing — already provides plenty of submaximal aerobic stimulus. The key is recognising that all training contributes to your conditioning, not just dedicated “roadwork.”

So what’s the takeaway? If you’re a moderately to well-trained boxer, your conditioning focus should shift toward short, high-intensity methods like Sprint Interval Training or targeted High-Intensity Interval Training. These not only deliver faster, more meaningful adaptations but also free up valuable time to sharpen your skills in the ring.

I've dropped a full 2 part series over on YouTube where I break down the science behind these findings, show how to test your current conditioning level, and explain exactly how to implement these high-intensity strategies without burning out. You won’t want to miss it.

Watch them here