“The Level of Flexibility of the Elderly in the Healthy Heart Gymnastics Community at the Sidoarjo Youth, Sports and Tourism Office”. COMPETITOR: Jurnal Pendidikan Kepelatihan Olahraga, vol. 17, no. 2, Aug. 2025, pp. 2073-9, https://doi.org/10.26858/cjpko.v17i2.294.