Confidence in the gym comes from preparation. Try to go to the gym when it's less busy or practice technique at home without weights.

Dumbbells are great for beginners and accessible. Barbells are best for getting strong and lifting heavy, and kettlebells can help power and stamina.

Chris Hemsworth demonstrated a workout on Instagram that simply involved him cutting chunks of wood with an axe, which can work out the whole body.

Peloton instructor Jess Sims told Insider push-ups and single-leg deadlifts help to build strength, prevent injury, and improve running.

Get fit even if you're new to exercise. Learn how to lift weights, do pull-ups, planks, and target each muscle group with Insider's guide.

Whether you're a newbie or advanced weightlifter, you can build more muscle by avoiding common mistakes like overtraining and under eating.

To make weight training an aerobic exercise, you can shorten rest periods between sets. You can also lift lighter weights for longer, experts said.

Leg exercises, like hip thrusts and Bulgarian split squats, are a great way to build shapely glutes, personal trainer Lucie Cowan said.

Cardio makes you fitter, which helps you to recover better from strength workouts, personal trainer Luke Worthington told Insider.

Make sure you're lifting heavy and hard enough, and don't neglect nutrition and recovery, personal trainer and nutritionist Harry Smith said.

Your workouts are less important than your nutrition if you want to lose fat, trainerJordan Syatt told Insider. Focus on eating in a calorie deficit.

To ensure you have energy to complete your weight workout, doing cardio after strength training might be best, according to personal trainers.

It can be intimidating to pick up weights if you only do cardio or yoga, but those skills can translate into strength training, Dr. Lady Velez said.

Firming up your body requires building muscle with a traditional strength training programme. Don't fear weights, you won't suddenly bulk up.

The Icelandic athlete initially took up the sport to "lose weight and get a boyfriend," she said. Her aim is now "to normalize the strong female body."

It's possible to work out hard but not build strength and muscle. Make sure you aren't making common gym mistakes, like overtraining or under-eating.

Using kettlebells incorrectly can cause wrist pain or bruises. During a swing, don't grip the kettlebell too tightly, Phase Six trainers told Insider.