Final answer:
Isolation exercises should not always be performed in a training session; their inclusion depends on individual fitness goals. Compound exercises are often the focus for overall strength, while isolation exercises are good for targeting specific muscles.
Step-by-step explanation:
The statement that isolation exercises should always be performed in a training session is false. Isolation exercises, which work a single muscle group at a time, are one component of a well-rounded fitness program. However, whether they should be included in a training session depends on the individual's goals. For instance, someone focusing on strength may prioritize compound exercises that work multiple muscle groups simultaneously, which are often more effective for overall strength development. On the other hand, isolation exercises can be beneficial for targeting specific muscles for growth or rehabilitation purposes. What is most important is creating a balanced workout routine that aligns with personal fitness objectives.