Final answer:
You need to adopt a fitness program and stick to it to be in good shape, which requires commitment and determination, as well as potentially embracing diversified health strategies.
Step-by-step explanation:
To complete the collocations: You need to adopt a proper fitness programme and to stick to it. I was in good shape a year ago but then I became a bit lazy.
Committing to a fitness programme is essential for maintaining good health, much like following a strict diet or regimen is for an athlete in training, as per the third passage. Being consistent and having the determination to stick to your goals, despite the challenges that may arise, is integral to success in any health and fitness journey.
Moreover, it's important to note that changes in health can lead to considering varying lifestyles or remedies as indicated by the sentiments in the first and second passages.
Whether it's through a change of scene to uplift one's spirits or John's attempts to enhance health through cod liver oil, tonics, and nutritious food, wellness often involves a multifaceted approach.