Plaintiff was injured when, while engaged in fitness training at defendant gym, she fell after being directed by her personal trainer (defendant‘s employee) to perform jump repetitions on an exercise ball. Plaintiff‘s opposition to defendant‘s showing of entitlement to judgment as a matter of law based on an assumption of the risk defense, raised triable issues of fact that warrant the denial of the motion. Such issues include whether the trainer, knowing that plaintiff had osteoporosis and had recently had surgery, unreasonably increased the risk of harm to plaintiff by recommending that she perform an advanced exercise with multiple repetitions (see Mathis v New York Health Club, 261 AD2d 345 [1st Dept 1999]; see also Corrigan v Musclemakers, Inc., 258 AD2d 861, 863 [3d Dept 1999]); whether the trainer was in a proper position to help guard against plaintiff falling during the exercise; and whether plaintiff voluntarily assumed the risks or was following the trainer‘s expert advice and encouragement while attempting to complete the exercise (see Mathis at 346). Concur—Tom, J.P., Sweeny, Moskowitz, Renwick and Clark, JJ.