Which arm and abdominal exercises to tone muscles are considered effective?

Cardio Mix: The best way to lose weight is cardio & a balanced diet. However, do not always do the same exercise or you will increase your risks for stress injuries. Mix things up w/ running, biking, swimming, or circuit training. Ultimately you need to burn more than you consume. Exercises such as crunches, planks, sit-ups, etc are good for toning the abdominal muscles, but cardio is best for weight loss.