Resistance training is safe and beneficial during a normal, uncomplicated pregnancy.
Exercises can be bodyweight focused, with the use of other equipment such as resistance bands and free weights (e.g. dumbbells) or anything where you're pushing and pulling against something. Therefore, there's plenty of opportunity to add variety to your workouts and keep you motivated - hooray!
Resistance training is essentially functional exercise in that we can apply it to our movements in everyday life (lifting, carrying etc). When performed on a regular basis (as little as two times per week as per current government guidelines), you will see a direct positive impact in how you perform these everyday movements from both a technique and strength perspective
There are a multitude of other benefits that come from practicing resistance training in pregnancy including:
Improved muscular strength and endurance to help delay the natural decline in muscle mass and bone density later in life
Improved ability to lift and carry your baby post birth
Improved metabolic rate
Reduced lower back pain
Reduced laxity of soft tissues
Reduced recovery time post birth
Reduced need for insulin therapy (for those women with gestational diabetes)
If you were practicing resistance training before pregnancy, you can continue to do so whilst making adaptations along the way depending on your stage of pregnancy and how you feel.
If you are new to resistance training it's perfectly safe for you to start in pregnancy with a gradual approach.
The key is knowing what types of exercises are safe throughout and being prepared to adapt your routine along the way whether that's changing the positions or exercises you do, decreasing / removing weights or trying other tools.
There are certain contraindications which make exercise not viable in pregnancy and others which may require medical approval beforehand. Please consult your GP, midwife or healthcare professional if you have any concerns or questions about exercise in your pregnancy. Everyone is different and what may be deemed safe for one person may not be safe for another.