Several times a week, I conduct in person classes which are performed at high intensity. In a CrossFit environment, people really get what this is meant to feel like. That 100% max out on the air bike that leaves your legs like jelly. The slam ball finisher which leaves you feeling your pulse in your eyes. The sprints… Oh, God, the sprints.
But in a mainstream gym environment, this is often very difficult to replicate. Especially if you’re used to exercising alone, you may not have ever felt that sort of physical effect before.
To some extent, I can control the intensity by selecting exercises which are low skill and so can be performed flat out without the risk of injury – that’s for the trainer to sort out, and that’s what I do. Exercises are chosen carefully, scaled appropriately and paired with other movements which will produce a desired effect. You don’t have to worry about any of that, that’s why I’m there.
However, you must approach the movements with intention. If it’s a HIIT class, it’s not meant to be a comfortable 60-70% aerobic effect. You shouldn’t be able to check a text message during the interval. You should be resting – much needed rest, because your working periods were really very hard! If you’re not working as hard as you can, the 30 or 40 seconds of work at your comfortable endurance pace is just 40 seconds of faffing about and will get you precisely no-where – your heart rate probably isn’t even in the aerobic zone after those intervals, and with the rest ratio bringing your heart rate back down… Well, you might as well not bother.
It’s hard to say that as a trainer, but it’s true. I understand the intention of coming to the gym, and participating in classes, but not all classes should feel the same or produce the same effects on you, physically.
A HIIT class should leave you feeling like “holy smokes, what on earth was that?!” and if you don’t want to feel like that – simply choose another class. There are tons of low impact, aerobic workout classes available. But the stimulus in that particular class is high intensity interval training – it’s what the initials stand for. If that’s not for you – that’s cool, it’s not for everyone – just do something else because you won’t get the outcomes you’re looking for.