The makers of the popular Bowflex fitness machine are recalling nearly 800,000 units after dozens of people reported injuries from mechanical problems, the government announced Tuesday.

This marks the second large recall of Bowflex (search) equipment this year. In January, the machine's manufacturer issued a voluntary recall of about 420,000 units after reports of similar mechanical problems.

The latest recall affects 680,000 Bowflex Power Pro systems and 102,000 Bowflex Ultimate Fitness Machines, manufactured by The Nautilus Group (NLS), of Vancouver, Wash.

The Consumer Product Safety Commission (search) says the machine's seat can unexpectedly break on the Ultimate model and Power Pro with "Lat Tower." There were 46 reports of such incidents and two of those were serious injuries requiring stitches to the head.

Another failure involves the machine's backboard bench unexpectedly collapsing when it is in the incline position on Power Pro models without the "Lat Tower." There were 42 reports of this failure and subsequent injuries to the back, neck and head, none of which were serious.

The company issued its recall in January after reports of more than 70 injuries due to the backboard bench failure and problems with the "Lat Tower." That piece — used to strengthen the upper body — can weaken over time and collapse, injuring the user's back, head and shoulder.

The recalled machines were sold at fitness stores and through informercials and direct mail around the nation between 1995 and April of this year. The systems cost between $1,200 and $1,600, depending on the model.

Consumers are advised to stop using the backboard bench in the incline position and contact the company to receive a free repair kit. Customers who participated in the recall in January and owners of the Ultimate systems will automatically receive a kit, the company said. Where owners names are known for all models, the company will contact them as well.

Consumers can call Bowflex at 1-800-820-8604 to receive the repair kit.