DENVER — Moderate to vigorous exercise during the in vitro fertilization (IVF) or egg freezing process lowers patient stress levels and does not produce worse outcomes than for patients who do not exercise, according to research presented at the 2024 American Society for Reproductive Medicine (ASRM) Scientific Congress.

The randomized control trial of more than 200 women showed no cases of ovarian torsion in either group. The quality of the resulting eggs was also comparable in both groups.

Maren Shapiro, MD, a reproductive endocrinologist at the University of California, San Francisco, and lead researcher, said resting throughout the ovarian stimulation process should not be the default plan for every patient.

“Mild to moderate exercise that feels right for your body is probably fine,” Shapiro said.

IVF or egg freezing requires 2 weeks of injections to stimulate the development of eggs, which are retrieved at the end of the period. Ovaries are enlarged during the process, which reproductive endocrinologists hypothesize may increase the risk for torsion because of excessive stimulation.

As a result, some reproductive endocrinologists advise no exercise at all.

Ovarian stimulation “is incredibly time-consuming, incredibly stressful, incredibly emotional, and incredibly expensive,” Shapiro said, adding that these factors lead her interest in researching potential improvements to quality of life among patients.

“You’re putting someone through this super stressful process and then taking away their stress relief mechanism, which feels extra cruel to me.”

She cautioned that the study was underpowered to prove that exercise does not cause torsion and will still support patients who want to rest during the 2 weeks.

Letting People Exercise

The randomized controlled trial compared stress levels in 107 women who exercised with another 106 who did not during the IVF stimulation or egg freezing process. Those who exercised were asked to complete at least 150 minutes of any type of moderate or 75 minutes of vigorous exercise per week. The exercise group logged their activity for an additional 2 weeks after egg retrieval and used a wearable monitor.

Shapiro and her team discouraged the exercise group from suddenly starting CrossFit or tire throwing but rather to keep active with brisk walks or time on the treadmill.

Shapiro and colleagues measured reduction in stress levels using the Perceived Stress Scale. Before the study began, participants in both groups (median age, 33 years) had similar levels of perceived stress — a median of 22 for the exercise group and 21 for the non-exercise group, indicating moderate levels of stress. After the trial was over, the exercisers saw stress levels drop by 1 point, while non-exercisers had increased stress by 2 points (P = .04).

People who said they were already regular exercisers (79 people of the 107 in the exercise arm) saw the largest drop in stress levels if they were allowed to continue exercising than regular exercisers who chose to stop. Those who did not exercise much before the trial saw a rise in their stress levels whether they were allowed to exercise.

“In people who exercise regularly, telling them to stop exercising really causes negative effects on their mental health,” Shapiro said.

Baseline Activity Level Matters

Vinita Alexander, MD, a reproductive endocrinologist and clinical instructor at Washington University in St. Louis, St. Louis, Missouri, said while the study had a group that did not exercise at all, most of her patients will continue some level of activity, even if minimal.

“Most physicians will say walking, swimming, yoga, or light exercise is okay,” she said. “Most clinics will advise against high impact or strenuous exercise” during ovarian stimulation.

The outcome that stress rose among those who newly started exercising caught Alexander’s attention.

“Going into IVF at a good baseline of activity may be really important for overall handling of stress,” Alexander said.

Amanda Adeleye, MD, has cared for torsion cases caused by intercourse or turning over during the night.

“There are many things besides exercise that can potentially lead to ovarian torsion, although overall the risk of torsion is very low,” said Adeleye, a reproductive endocrinologist and medical director of CCRM Fertility, a fertility clinic in Chicago.

Adeleye encourages exercising until day 5 or 6 of stimulation but discourages jumping, sudden movements, or contorting their torso in a yoga pose.

“Do what makes sense to you. And if you feel that the ovaries are moving around a bit, that’s probably when it’s time to stop,” Adeleye said.

Shapiro reported grants from Apple Health, Ferring Pharmaceuticals, and Optum Health. Adeleye reported relationships with Carrot, Compass, and Roon.

Marcus A. Banks, MA, is a journalist based in New York City who covers health news with a focus on new cancer research. His work appears in Medscape Medical News, Cancer Today, The Scientist, Gastroenterology & Endoscopy News, Slate, TCTMD, and Spectrum.