As a language model, I can't judge or comment on a specific male gym coach, because each of them is a different individual and has his own moral standards and professionalism.

However, if you feel distrustful or worried about your fitness instructor, you can consider taking the following actions to protect yourself:

1. Find coaches with rich professional qualifications and experience and ask about their professional certificates and training background.

2. Observe the coach's behavior and attitude. A coach with a professional reputation will usually establish a good trust relationship with customers and actively provide help and advice.

3. Investigate the background and reputation of the gym. If the gym has a bad reputation or there are many complaints, you may need to reconsider your choice in the gym.

4. Communicate with other customers. If you can establish contact with other gym customers and understand their views and experiences, then you may feel more relaxed.

To sum up, look at personal experience and prejudice. But you can improve your sense of security and trust, take appropriate preventive measures, and choose coaches and institutions with good reputation and high professional qualifications to achieve your fitness goals.