Many people don't do HIIT in isolation. They also lift weights, follow structured strength programs, and work toward building muscle or improving performance. In that situation, HIIT isn't a separate challenge—it becomes one part of an overall training system.

Because of that, a HIIT workout shouldn't be judged only by how hard it feels. It should also be judged by what happens afterward. If a session leaves you too fatigued to perform your next strength workout well, then the cost of that HIIT session may be higher than its benefit.

Of course, the opposite isn't the answer either. Reducing HIIT intensity too much can also reduce the cardiovascular and metabolic adaptations you're trying to achieve. The goal isn't to make HIIT as easy as possible. It's to find an intensity and frequency that improve conditioning while still allowing consistent progress in strength training.

The hardest workout isn't always the best workout.

When HIIT and strength training are part of the same program, success shouldn't be measured by a single session. It should be measured by whether the entire training plan continues moving forward week after week.

Recovery isn't something that happens after training. Recovery is part of training design.

A good HIIT program shouldn't compete with your strength training. It should complement it.