Walking and jogging around the Lake are possible along sidewalks and through the coves and the new Crystal Lake Park in all seasons of the year.

Very low, fee based public swimming is permitted during designated dates in June, July and August at the Crystal Lake Park beach; that is, the official beach at the Bathhouse. For exact dates call Newton Parks, Recreation and Culture at 617 796-1500. At these times changing and restrooms are provided, life guards are on duty and an aqualator is operating. The aqualator functions to circulate water and disperse bacteria. The water is tested in this area for e-coli, to ensure state standards for swimability. Also, swim lessons are available to the public and to local summer day camps. The facility is open each day of the week during daylight hours. Shore access in this area is available in all seasons including the off seasons.

Fishing is a popular sport at Crystal Lake. As early as 1871, the lake was stocked to provide for fishing. This continues nowadays with stocks of up to 400 brown and rainbow trout yearly. As these fish are not capable of breeding, the fish population is controlled from year to year.

Boating is permitted in all seasons from Cronin Cove. There is a boat unload/load zone for this purpose at Cronin Cove which is close to the water edge.