The phrase "spots where you might spot some spotters" commonly refers to gyms. In gyms, spotters are individuals who assist others during weightlifting or exercise to ensure safety and proper form. Thus, gyms are natural places to find spotters actively helping exercisers. This is the answer to a crossword clue that plays on the word "spot" in multiple ways, referring both to a location and the act of spotting someone while exercising.

If considering "spotters" in other contexts, such as planespotters, specialized places like airport spotter zones are where you might find such spotters, but the crossword clue's common and straightforward answer is "GYMS".