The Thai star had a dream run ahead of the Rio Games when she won consecutive titles in India, Malaysia and Singapore.
But a failed drug test, of which she was absolved by BWF later, and a nagging knee injury saw her crash out of the Olympics in the pre-quarters.
The 22-year-old regained her fitness just ahead of the All England Championship and reached the finals before losing to Chinese Taipei's Tai Tzu Ying.
"I struggled for six months, only regaining my fitness after Dubai Super Series Open. After that I worked on my upper body and I was 100 percent before All England.
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"I was champion in three consecutive events last year but I have to take a call if I will play all three tournaments. I know I have to defend my points but I also have to manage the workload and have to take care of my body.
Ratchanok said she will need to work harder to compete as the game is changing each day.
"I have to keep training hard because it is not about technique, it is about power and speed like Tai Tzu Ying. When she was young, she didn't have good fitness but now probably she has a six pack," she laughed.
Talking about Saina Nehwal and PV Sindhu, Ratchanok said: "They have different style. Sindhu is tall and she has an attacking game but she is improving in her defence now."
"Saina is a rally player and has full power in her smash. So I don't know who is better, it is very tough for me."
Ratchanok was a bit rusty today as she staved off a challenge from young Chinese Gao Fangjie 21-15 21-19.
"She looks like Li Xuerui. She has got good technique but she needs more experience. The young Chinese girls are good, they just need more experience and they too will do well," she signs off.