Vibration plates, lifting during pregnancy, and a new era for the SBS podcast (Episode 115)

Vibration plates are devices, varying from cheap Amazon models to expensive gym equipment, that vibrate at different intensities. On social media like TikTok, they are claimed to aid weight loss, burn fat, improve flexibility, enhance blood flow, reduce muscle soreness, build strength, decrease cortisol, and work as a lymphatic draining machine.

Vibration plates work by causing rapid, small vertical movements that create quickly oscillating gravitational forces on the body. This is hypothesized to activate involuntary reflex arcs between muscles and the spinal column, making muscles contract and relax rapidly to maintain equilibrium, which is termed the tonic vibration reflex.

Vibration therapy dates back to ancient Greeks and Romans who used uneven carts and even saws wrapped in fabric for healing. In the 1800s, Gustav Zander developed apparatuses to simulate horse riding, and later John Harvey Kellogg created vibrating chairs. The Russian Space Program used it in the 1900s for astronauts, and Gus Vandermeer developed the modern Power Plate in the 1990s for Olympic athletes.

While vibration plates do slightly increase energy expenditure and fat oxidation, the effect is extremely trivial. Research shows that over a 12-24 week intervention, the additional fat loss might only be around one kilogram. To burn one additional pound of fat, one would need to spend approximately 45 hours on a vibration plate.

The most recent ACOG guidelines (2020, reaffirmed 2023) indicate that most types of exercise are generally safe during pregnancy for women without medical or obstetric complications. If a woman was already engaging in vigorous exercise before pregnancy, she can typically continue, monitoring closely and consulting her doctor.

Current guidelines still express trepidation about scuba diving (due to fetal pulmonary circulation), exercise at high altitude for those unaccustomed, long-duration or high-intensity exercise in the heat (due to circulatory and thermoregulation concerns, and neural tube defects), very heavy resistance training (due to large blood pressure increases and relaxin hormone effects), supine resistance training (due to fetal weight compressing blood vessels), and the valsalva maneuver (due to high blood pressure).

Guidelines change slowly due to the 'first do no harm' principle and ethical concerns about randomized controlled trials. Research typically follows a two-step process: first, observational studies of women already engaging in potentially 'risky' activities are conducted. If these suggest safety, then controlled trials can be approved to confirm findings, leading to guideline updates.

The observational study found that women who engaged in heavy resistance training (including Olympic lifting, supine exercise, and Valsalva maneuver) during pregnancy generally had pregnancy, delivery, and postpartum complication rates at or below those of the general population. Those who maintained pre-pregnancy training levels had 50% lower complication rates. The only potential negative was higher postpartum urinary incontinence, but this wasn't tied to exercise variables.

The literature suggests that heavy resistance training likely doesn't cause or worsen urinary incontinence. While lifters may experience incontinence more frequently during max efforts due to higher intra-abdominal pressure, this often reveals an existing threshold rather than creating the problem. Studies show incontinence is more strongly linked to age and number of children than lifting habits or intensity.