This is the 9419th most frequent Swedish word.
friskt
"Friskt" means "healthy" or "fresh" in English.
Here, 'friskt' is serving to describe the appearance of the sea, implying that it looks clean, rejuvenated, or invigorated.
Havet såg friskt ut efter stormen.
The sea looked fresh after the storm.
In this sentence, 'frisk' pertains to the nature of the walk, indicating its brisk and invigorating pace and quality.
Jag brukar gå på en frisk promenad om morgonen.
I usually take a brisk walk in the morning.
Here, 'friskt' describes the weather, suggesting it was cool, clean, and refreshing.