You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Outcome", "Participant", "Intervention"].

Please return the output as a JSON object of the format: {"Participant" : ["patients with COPD", ...], "Intervention" : ["Atenolol", ...], "Outcome" : ["blood pressure", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Comparing the effectiveness of peer mentoring and student mentoring in a 35-week fitness program for older adults . To investigate the applicability and effectiveness of a peer-mentored exercise program , this study compared the retention and participation rates , and physical improvements of older adults trained by peer mentors ( PM ) to a group trained by young qualified student mentors ( SM ) . A group of older adults were prepared as peer mentors through a 30-week preparation program . Later , 60 older adults ( mean ± SD age : 68.7 ± 6.1 years ) were recruited and randomly assigned to either the PM or SM group . Both groups completed an identical 35-week fitness program . Pre- , midterm- and post-training assessments of fitness were completed and rates of participation and retention were documented . The same retention rates were observed in the two groups , but SM group had higher participation . Both groups improved significantly in all measures of fitness and there were no significant post-test differences between the groups in the fitness measures . Findings suggest that the peer mentor model is applicable in an older adult exercise program and may be as effective as a program mentored by young professionals .
{"Intervention": ["peer mentoring", "peer-mentored exercise program", "trained by peer mentors ( PM ) to a group trained by young qualified student mentors ( SM )", "student mentoring"], "Outcome": ["effectiveness", "post-training assessments of fitness", "applicability", "all measures of fitness", "and rates of participation and retention", "groups improved significantly", "had higher participation", "physical improvements", "retention and participation rates"], "Participant": ["older adults ( mean \u00b1 SD age : 68.7 \u00b1 6.1 years )", "older adult", "older adults", "60", "older adults ."]}