Introduction: The practice of stretching is commonly used in the preparation of activities and/or physical exercises that require some component of flexibility, strength, endurance and muscle power. This explains the high growth in recent decades of studies investigating the effect of stretching, mainly static and dynamic, when performed immediately before activities that aim to develop these physical capacities. Despite the growing interest of scholars on this topic, the long-term impact of dynamic stretching on flexibility, strength performance, endurance and muscle power is still not fully understood. In addition, a type of dynamic stretching little explored in the literature needs investigation: the stretches used during Pilates exercise sessions. The effects of these stretching exercises on a physical conditioning program based on Pilates exercises in the young adult population are not yet known. Objective: To verify through a randomized clinical trial the effects of stretching in a conditioning program based on Pilates exercises on flexibility, strength, endurance and muscle power. Methods: In this study, 32 young adults of both sexes will be randomized into two groups: 1) Traditional Pilates; 2) Pilates Without Stretching. The Traditional Pilates group will perform a protocol of stretching exercises followed by muscle strengthening. The Pilates Without Stretching group will perform an exercise protocol consisting only of muscle strengthening exercises. Muscle strength results will be evaluated by 1 repetition max by elastic resistance; trunk muscle strength/endurance by the 1-minute abdominal test and the Sorensen test, respectively; vertical jump performance by the sargent jump test; handgrip strength by the handheld dynamometer and flexibility by the sit-and-reach test. These physical capacities will be assessed at baseline and after 8 weeks of intervention. Interventions will be performed three times a week for 8 weeks. The analysis will be performed with intent-to-treat analysis and adjusted covariance for baseline outcomes.

Inclusion Criteria:

• women between 18 and 45 years of age
• normoweights (Body mass index between 21 to 25 kg/m2)
• not be participating in physical exercise programs for at least six months
• be healthy, according to the Physical Activity Readiness Questionnaire
• not report any medical restrictions for physical exercise
• no history of injury, trauma or illness within the last six months
• not having undergone previous surgery in the last six months
• not have musculoskeletal, cardiorespiratory and neurological disorders that prevent the performance of assessment and intervention protocols
• not be under the action of medications that cause muscle relaxation or that can inhibit muscle tonic action
• not use food supplements or anabolic steroids
• not being on a calorie-restricted diet

Exclusion Criteria:

• start practicing another type of physical exercise during the study period
• not being able to perform the pre-intervention assessment or the intervention exercise protocol
• emergence of lesions that do not allow the continuity of interventions
• withdraw from participating in the study

Data regarding the study will be shared in the publication linked to this record, as a main part of the manuscript and supplementary documents when necessary.