I would just start off with the Airofit Pro. That is what I started off with. I saw the benefits from the Airofit Pro and did a lot more research on Respiratory

I would just start off with the Airofit Pro. That is what I started off with. I saw the benefits from the Airofit Pro and did a lot more research on Respiratory Muscle Training before going to the IDIAG P100. Of course, I use both the Airofit Pro and the IDIAG P100, every single day, although for a different set of purposes. But, you should absolutely start off with the Airofit Pro, before even considering the IDIAG P100. IDIAG (the company that makes the IDIAG P100) just raised the price on their device, likely in the past couple of weeks. I got it for around 650 EUR. I cannot believe that they just about doubled the price. I found that out about a couple of days ago, and it really disappointed me, even though it truly is a remarkable device. There is an older model of this device, that is on sale and specifically does isocapnic hyperpnea (see: https://www.spirotiger.net/en/products/spirotiger-go https://www.spirotiger.net/en/products/spirotiger-go). You can also find used ones online. Besides being unfit and needing to lose weight, I also have health conditions that worsen my exercise tolerance. I use the IDIAG P100 to increase my exercise tolerance, and it helps me, tremendously. There are studies to prove the significant increase in endurance, if you search for "isocapnic hyperpnea", "isocapnic hyperpnoea", "normocapnic hyperpnea", or "normocapnic hyperpnoea", on like Google Scholar, for example. You can also try searching for "SpiroTiger" or "Spiro Tiger" (an older model to the successor IDIAG P100) on like Google Scholar to verify. A byproduct of using the device is that it really calms me down for the rest of the day, when I use it in the morning. I sometimes also do Respiratory Muscle Endurance Training (RMET) about 2 hours before I go to sleep and I sleep a lot more restfully and my sleep quality has improved, because I am calmer. It also helps me wind down at night. I agree with you that it is extremely steep for an initial ask. The device came out in 2020, also. I would wait for more reviews. This technology is used more in Switzerland and Germany, so you may want to keep this in mind when searching for reviews. You may need to use Google Translate when scoping out info online. But, I would absolutely wait. The Airofit Pro definitely makes you more aware of your breathing, basically all the time. I started off with that before going to the IDIAG P100. When I benefited from the Airofit Pro, I decided to do more research into Respiratory Muscle Training and I learned about RMET (and isocapnic hyperpnea), and I figured out that it would be a good idea to augment my training with that, as I had already been getting great results with the Airofit Pro. But, isocapnic hyperpnea has helped me the most, overall.