New research suggests weightlifting causes a transient and dramatic fluctuation in IOP. Regular exposure to resistance training combined with the resultant spikes in pressure may be a significant risk factor for glaucoma, researchers warn.

This prospective cohort study included 24 participants (nine women) who were an average age of 22.7 years. The mean baseline IOP was 13.9mm Hg with an average BMI of 24.5.

The team measured the maximum load for a single lift for each participant and documented an average of 331.9kg. Participants then performed three leg press regimens: one repetition using 95% of maximal load (1RM), six repetitions using 75% of maximal load (6RM) and isometric push against a weight much heavier than maximal load (ISO).

The investigators observed transient increases in IOP across the 1RM, 6RM and ISO exercises, with an average increase of 26.4mm Hg (23.7mm Hg to 28.7mm Hg) to reach an average max IOP of 40.7mm Hg (27.8mm Hg to 54.2mm Hg).

“It should be noted that this study has been carried out in a healthy young population, and, thus, the external validity of these results in glaucoma participants requires further investigation,” the study authors concluded.