The antonyms for the word "more adrenalizing" would be "less stimulating," "lackluster," "dull," "boring," "unexciting," and "uninspiring." These words denote a sense of uneventfulness, inactivity or boredom, which is the opposite of the thrilling, exciting, and energetic experiences that "more adrenalizing" evokes. Visiting museums or reading books might be considered less stimulating compared to outdoor activities such as bungee jumping or skydiving. Some people may prefer calmer, quieter activities, but those who seek high energy and excitement would seek activities that evoke a sense of adrenaline rush. Such activities are generally more dangerous but can be thrilling for some people.