Modifiers matching exertion:

• unnecessary,
• heavy,
• strenuous,
• muscular,
• physical,
• stressful,

Simple categories matching unnecessary:

• therapy,
• treatment,
• exertion,
• toy,
• procedure,
• interference,
• practice,
• stuff,
• measure,
• surgery,
• test,
• medication,
• activity,
• information,
• thing,
• service,
• task,
• expense,
• misconception,
• intervention,
• radiation,