9/10 sleep science coach and longtime mattress tester with more than six years of experience, I consider a few topics to be ongoing passion projects. Finding mattresses that truly work for heavier bodies is one of them. Unfortunately, not all mattresses are equipped to support people with larger body mass. It only gets trickier when heavy people cosleep with a partner who has a different body type. Ultimately, both people's sleep schedules suffer. The term “plus-size sleeper" encompasses several different variables. It could mean higher body mass due to height, or a larger body shape regardless of height. For instance, I stand at 5’10," and though I'm not considered plus-size, I weigh 170 pounds, give or take. My husband is 6’4” and 220 pounds. I have a better example, though, of disparate cosleeping partners: my parents, who have owned a Saatva HD mattress for two years. My dad is a former collegiate basketball player at 6’6” and just over 300 pounds.…