How to choose the right dumbbell/bar weight for training?

Weights should be carefully chosen to ensure that the exercise is performed with proper technique, keeping control over your body and equipment, while also effectively activating the target muscle group. 

Finding the right weight is crucial for every exercise in your workout. The weight should allow you to maintain a pace, complete the necessary number of repetitions, and sustain the required time under load (for timed exercises). 

To determine the right weight for working out, start light and perform the necessary number of repetitions. If it feels too easy and doesn't challenge you, increase the weight. Conversely, if the weight feels heavy and hinders your technique, reduce it to minimize the risk of injuries. 

When you are able to complete all the planned sets and repetitions of the exercise while maintaining the technique, you can increase the weight to advance in strength and muscle growth: 

• for large muscle groups such as legs, back, chest, and partial shoulders, in multi-joint/basic exercises, add 5 kg (total) in the last set;
• for smaller muscle groups like triceps, biceps, calves, forearms, and abs, add 2.5 kg (total); 
• consider adding the same weight in the penultimate set to continue to challenge your muscles. 

Remember to progress gradually and always prioritize proper technique.

Listen to your body, and don't push yourself with excessively heavy weights. It's always better to do more repetitions with a lighter weight than risk injury. By choosing the right weight, you'll achieve a more efficient workout and reach your fitness goals.