No you don’t. You can purchase the PowerLung Resistance Cells Set for the model with the next resistance level above your current model. Remember to keep your current Resistance Cells Set because you can still use them, too. Use your new, higher level Resistance Cells Set for your strength or power training program. Use your existing, lower level Resistance Cells Set for you endurance training program. Depending on how and why you are using your PowerLung model, you may also be able to use the lower level Resistance Cells Set as part of in-sport training.
Knowledge Base > FAQ > Using PowerLung > I’ve used my PowerLung model regularly and just don’t feel like I’m getting any resistance from it even at the maximum settings. Do I need to buy a different PowerLung model?