Meaning: 'Vigorous' means strong, healthy, and full of energy, particularly in the context of physical activity.

Wrong options:

• mindfulness: 'Mindfulness' refers to a mental state of awareness and focus, which does not describe the physical nature of the workout.
• sedentary: 'Sedentary' describes a lifestyle characterized by little physical activity, which contradicts the idea of hiking as a workout.
• backpack: 'Backpack' is a noun referring to a bag carried on the back, which does not fit grammatically as it does not describe the type of workout.
• muscles: 'Muscles' is a noun that refers to body tissues that contract to produce movement, but it does not describe the workout itself.
• well-being: 'Well-being' refers to a state of health and happiness, which does not describe the intensity of the workout.

Correct answer: well-being

Explanation: The term 'well-being' is a noun that refers to a state of being comfortable, healthy, or happy. It fits contextually as it describes the mental benefits of being in nature, aligning with the calming effect mentioned in the passage.

Meaning: 'Well-being' refers to the state of being comfortable, healthy, or happy, particularly in a mental or emotional context.

Wrong options:

• mindfulness: 'Mindfulness' refers to a mental practice of being aware and present, which does not directly relate to the overall state of health and happiness.
• vigorous: 'Vigorous' is an adjective that describes physical activity, not a state of mental health or happiness.
• sedentary: 'Sedentary' describes a lifestyle with little physical activity, which is the opposite of well-being in this context.
• backpack: 'Backpack' is a noun referring to a bag, which does not relate to mental health or well-being.
• muscles: 'Muscles' refers to body tissues that enable movement, which does not pertain to mental health.

Correct answer: backpack

Explanation: The word 'backpack' is a noun that refers to a bag carried on the back, which fits contextually as it describes an item that can be carried while hiking, enhancing the physical challenge of the activity.

Meaning: 'Backpack' is a bag that is carried on the back, typically used for carrying supplies while hiking or traveling.

Wrong options:

• mindfulness: 'Mindfulness' is a noun related to mental awareness, which does not fit as it does not describe a physical object.
• vigorous: 'Vigorous' is an adjective that describes intensity, not an object that can be carried during hiking.
• sedentary: 'Sedentary' describes a lifestyle with little activity, which does not fit as it does not describe an item related to hiking.
• muscles: 'Muscles' refers to body tissues, which does not fit as it is not an object that can be carried.
• well-being: 'Well-being' refers to a state of health and happiness, which does not describe a physical item.

Correct answer: muscles

Explanation: The term 'muscles' is a noun that refers to the tissues in the body that enable movement. It fits contextually as it describes the physical benefits of hiking, specifically how it strengthens various muscle groups.

Meaning: 'Muscles' are tissues in the body that contract to produce movement, essential for physical activity.

Wrong options:

• mindfulness: 'Mindfulness' refers to a mental state and does not relate to physical strength or fitness.
• vigorous: 'Vigorous' is an adjective that describes intensity, not a physical body part.
• sedentary: 'Sedentary' describes a lifestyle with little physical activity, which contradicts the idea of strengthening muscles through hiking.
• backpack: 'Backpack' is a noun referring to a bag, which does not relate to the physical aspect of hiking in terms of muscle strength.
• well-being: 'Well-being' refers to a state of health and happiness, which does not specifically address the physical aspect of muscles.