No, they’re simply getting tired.
“Exercise” is a specific term that implies you have a goal — the exercise is the protocol you follow to reach your goal. “Going to the gym” implies you’re getting tired.
“I want to front squat 150 pounds,” or “I want to do one pull-up,” are goals to increase strength; they have specific exercise protocols to follow. But, “I want to get stronger” will just make you tired.
“I want to get below 15% body fat,” is a goal with a protocol to follow. “I want to be shredded,” is just confusing.
“I want to run a 5K in less than 25 minutes,” is a goal. Spending 30 minutes on an elliptical is getting you tired.
Getting tired isn’t a bad thing. Zuma is a way to get tired, as is yoga, as are most sports. But they’re not forms of exercise, because exercise has a measurable result.