1, "speak fast" means to speak fluently, without pause or ambiguity.
2. "Walking fast" means walking steadily and effortlessly.
3. "Faster defecation" means easy defecation without constipation and frequent urination.
4. "Sleeping fast" means sleeping with high quality, falling asleep quickly, and being in a good mental state after waking up.
"Eating fast" means having a good appetite, eating well and finishing a meal quickly.