I don’t have ________, how should I modify?
Unfortunately, there is not a one-size-fits-all answer. However, while you work to bolster your available equipment, ask yourself or your training partners, “how long should the ________ take?” Once you know that information, you can determine if the goal stimulus is breathing, or muscle fatigue, or something else. With that information, you can work to mimic the stimulus. The primary keys here are: be flexible – it’s ok to do something slightly different. Create variance – change it up each time it comes up, and finally, go hard. The intensity is what creates the adaptation.