4 signs you're about to have a bad personal training session, according to experts

• Good personal trainers can help you make the most of your workouts safely.
• However, trainers that are unqualified or reckless may increase your risk of injury or burnout.

Working out is great for your health, and with proper technique and good coaching, even heavy weightlifting can be a safe, effective way to improve your fitness and well being.

However, there is some risk to physical activity, and side effects of working out too much or improperly can include fatigue, soreness, and even injury. Fitness coaches that are inexperienced or unqualified can amplify these side effects.

To avoid a bad experience with a personal trainer, make sure they're well-qualified, address your unique needs and prioritize good form throughout your training. Here are four red flags to look out for to gauge if a personal trainer is right for you, experts told Insider.

They're not clear about their experience or lack credentials

Before taking fitness advice from anyone, ask about their qualifications. Good trainers will be upfront about their education and certifications.

To be clear, sporting six-pack abs or being a beast in the gym isn't a coaching credential, since it's no guarantee they have the skills to help you do the same.

"Good coaches need to be certified, knowledgeable, on top of latest research, and experienced with communicating to people." Dominick Fortino, owner of Dutch Kills Fitness, previously told Insider. "Some of the greatest athletes of our time aren't the best coaches."

They don't discuss your fitness history, goals, and preferences

A good personal trainer is like a good medical professional, according to Michael Bultman, a nursing student, personal trainer, and group class coach at Park Slope CrossFit. Both should start by evaluating your overall health (and fitness) history. Talking through your experience is essential for a trainer to understand your unique needs.

"Even if a client's goal is to get buff, they still may have injuries or past operations that need to be understood before creating a training regimen," he said.

Coaches should also listen carefully to your goals as well as what types of exercise you like and don't like, and create a training plan accordingly.

"It's okay to hear 'I hate burpees please lord god don't make me do them' from a client. There are plenty of ways to create the stimulus required to increase cardiovascular stamina," Bultman said.

They throw you into a tough workout without assessing your movement first

A personal trainer who doesn't talk through your health history is a bad sign, but it's even worse if the first thing they do is assign you challenging, strenuous exercises.

"If a coach starts a client off with a very difficult workout without checking to see where their fitness is, it could cause injuries or health problems," Bultman said.

Even for experienced athletes, trainers should always start by going over the basics of good movement, to make sure you can add weight and intensity without injury.

Doing too much, too fast is also likely to lead to fitness burnout, making it even hard to reach your goals.

They stress intensity over proper technique and fundamentals

Just because a personal trainer makes you tired and sore doesn't mean you had an effective workout, experts say.

A coach should never prioritize heavy weight or a hard workout over high-quality movement and good form, since doing so is a recipe for injury, according to Bultman.

"If a coach does not harp on the fundamentals and proper techniques involved with weightlifting, things will not end well," he said.

You don't need to be intimidated or worry about getting hurt lifting even heavy weight, though - just be sure to find a quality coach and prioritize good form over trying to exhaust your body.