When it comes to strength training, it’s harder to build muscle if you don’t add variety. Strength-training resistance exercises use a stimulus, such as a weight, to give your muscles something to work against. Over time, your muscles adapt to that stimulus. To continue to strengthen your muscles, you need to introduce stimuli that are progressively more challenging. For example, you need to use progressively heavier weights or resistance bands.
Adding variety to your strength training workouts is also important. Try to incorporate different types of exercises and resistance into your routine. For example, use resistance machines at the gym, free or handheld weights, or resistance bands. You can also do pushups, pullups, situps, and other activities that require you to lift your own body weight.