Yes, we ship worldwide. Shipping costs are calculated at checkout based on your location. Domestic U.S. orders are processed within 2 business days and typically arrive within 5–7 business days. International orders can take 7–16 days depending on the destination and customs processing. You'll receive tracking information by email once your order ships.

Once your order ships, you'll receive a tracking number by email. Use that number to track your package directly through the carrier's website. If you haven't received tracking information within 3 business days of placing your order, contact us at info@o2trainer.com.

We use all major carriers, and local courier partners. You’ll be asked to select a delivery method during checkout.

Yes. For international orders, any customs duties, taxes, or import fees that apply upon delivery are the responsibility of the recipient. We have no control over these charges and cannot predict them in advance — they vary by country.

If your package is marked as delivered by the carrier but you haven't received it, please first check with neighbors and around your property. Unfortunately, we are not responsible for packages lost or stolen after being confirmed as delivered. We strongly recommend shipping to a secure address. For any concerns, contact us at info@o2trainer.com and we'll do our best to help.

We accept returns within 30 days of purchase. To be eligible, the item must be unused and in its original packaging. Items returned after 30 days, or that show signs of use, are not eligible for a refund.

Email us at info@o2trainer.com with your order number and reason for the return. We'll walk you through the process. Do not ship anything back without contacting us first.

Return shipping costs are the responsibility of the customer and are non-refundable. If you receive a refund, the cost of return shipping will be deducted from your refund amount.

Once we receive and inspect your return, we'll notify you by email whether your refund has been approved. Approved refunds are applied to your original payment method. Depending on your bank or card provider, it may take a few additional business days to appear on your statement.

We only replace items that are defective or damaged. If that's your situation, email us at info@o2trainer.com and we'll arrange an exchange for the same item. If you have a Lifetime Warranty, defective units are covered under that program.

No. Only regular-priced items are eligible for refunds. Sale items cannot be refunded.

The O2Trainer is an inspiratory muscle training (IMT) device that strengthens your diaphragm and intercostal muscles through controlled resistance breathing. It comes with 16 interchangeable resistance caps (ranging from 14mm to 1mm). You breathe in through the device, and the cap creates resistance that forces your breathing muscles to work harder — the same way lifting weights makes your arm muscles stronger. Over time, your lungs become more efficient and powerful.

Start with cap number 1 (14mm — the most open). If you're already an athlete with strong cardiovascular fitness, you can typically start around cap 3. Only move to the next cap when your current level feels easy during workouts. Never skip ahead — the progressive approach is what makes it safe and effective.

No — not when used correctly. This is a common misconception. Because your breathing muscles get stronger with each resistance level, your lungs pull the same amount of air through a smaller opening. You're working harder, not getting less oxygen. Always start at a comfortable resistance and progress gradually, and you will never deprive yourself of oxygen.

Yes. The O2Trainer is designed to be used at rest, walking, or during active workouts. It only restricts air intake (inhale), so you can fully exhale at all times. This allows it to be used during running, cycling, MMA training, and other high-intensity activities.

Yes, they work differently. High-altitude training reduces the amount of oxygen in the air, forcing your body to adapt — but it doesn't directly make your breathing muscles stronger. The O2Trainer uses progressive resistance to actively build those muscles. The two can complement each other, but they are not the same thing.

The O2Trainer is used by a wide range of people: competitive athletes (MMA fighters, runners, cyclists, swimmers) looking to improve endurance and VO2 max; people managing asthma, COPD, or other respiratory conditions; singers and wind instrument musicians who need diaphragm strength and breath control; and anyone who wants better energy, sleep, and stress management through stronger, more efficient breathing.

Yes. A clinical study involving 9 collegiate cross-country athletes was conducted by Dr. Frank B. Wyatt, EPc, Professor at Midwestern State University's Department of Athletic Training & Exercise Physiology. Every participant who used the O2Trainer increased their ventilatory muscle strength and improved the volume of air they could breathe per minute. Additional published medical research supporting inspiratory muscle training is available on our Science page.

Published research supports inspiratory muscle training for both conditions. For asthma, targeted breathing exercises can help manage symptoms and improve lung function over time. For COPD, IMT has been shown to reduce dynamic hyperinflation and improve exercise capacity. Bas Rutten himself has lived with asthma his entire life and developed the O2Trainer in part because of it. We always recommend consulting your physician before starting any new respiratory training program.

The O2Trainer is available with an optional Lifetime Warranty add-on for $19.99, purchased at checkout (or within 30 days of your device purchase). The warranty covers manufacturing defects and material failures under normal use conditions. It does not cover normal wear and tear, accidental damage, or products purchased from unauthorized third-party retailers.

Email info@o2trainer.com with your order number, clear photos of the issue, and a description of what happened. Wait for approval before sending anything back — unauthorized returns will not be processed.

You can reach our customer support team at info@o2trainer.com or by phone at (805) 657-3116. We typically respond within 1–2 business days.