The researchers asked students whether they experienced physical symptoms of stress, such as headaches, exhaustion, sleep deprivation, weight loss, and stomach problems.
More than 80 percent of students reported having at least one stress-related symptom in the past month, and 44 percent said they had experienced three or more symptoms.
In addition, it's been easier for their children to participate in after-school activities.
In 2013, research conducted at Stanford University found that students in high-achieving communities who spend too much time on homework experience more stress, physical health problems, a lack of balance in their lives, and alienation from society.
The researchers also found that spending too much time on homework meant that students were not meeting their developmental needs or cultivating other critical life skills.
Students were more likely to forgo activities, stop seeing friends or family, and not participate in hobbies.
“The data shows that homework over this level is not only not beneficial to children’s grades or GPA, but there’s really a plethora of evidence that it’s detrimental to their attitude about school, their grades, their self-confidence, their social skills, and their quality of life,” Donaldson-Pressman told CNN.
Kindergarteners received 25 minutes of homework per night, on average.
That study, published in The Journal of Experimental Education, suggested that any more than two hours of homework per night is counterproductive.
However, students who participated in the study reported doing slightly more than three hours of homework each night, on average.