# Effects of a Short-Term Supervised Exercise Program in Women with Breast Cancer  
[PERSON]  
1 Faculty of Nursing, Physotherapy and Podiatory, Complutense University of Madrid, 28040 Madrid, Spain; 1  
[PERSON]  
2 Physotherapy, Occupational Therapy and Speech Therapy Unit, Infanta Leonor University Hospital, Vallecas, 28031 Madrid, Spain; 2  
[PERSON]  
2 Physotherapy, Occupational Therapy and Speech Therapy Unit, Infanta Leonor University Hospital, Vallecas, 28031 Madrid, Spain; 2  
reporting a 20% chance of developing it before the age of 75, and a mortality rate of 10% [3]. Two years later, in 2020, the IARC estimated that there were 19.3 million new cancer cases and nearly 10 million cancer deaths worldwide [2]. The most commonly diagnosed cancers worldwide were female breast cancer with 2.3 million new cases (11.7%), followed by lung cancer (11.4%), colorectal cancer (10.0%), prostate cancer (7.3%), and stomach cancer (5.6%), with the most common causes of death being lung cancer with 1.8 million deaths (18%), followed by colorectal cancer (9.4%), liver cancer (8.3%), stomach cancer (7.7%), and breast cancer in women (6.9%) [4]. In the United States, it is estimated that there were approximately 2 million new cancer cases and over 600,000 cancer-related deaths in 2023, with a 40% probability of developing cancer at some point in life (12.9% female breast, 12.6% male prostate, 4.3% male colorectal, and 3.9% female colorectal) [5]. The World Cancer Research Fund estimated in 2018 that 18% of cancers in the United States (more than 300,000 cases of cancer each year) are directly attributable to suboptimal diet, physical inactivity, and/or excess adiposity [6]. Treatments for this disease are varied, with the most common being surgery, chemotherapy, radiation therapy, and immunotherapy [7; 8; 9]. Some of these treatments, due to their toxicity, result in multiple health-detrimental consequences that occur in addition to those caused by the disease itself. Some of these sequelae include lymphedema, central and peripheral nervous system impairments, cardiac alterations, decreased bone and muscle mass, among others [10]. One of the most prevalent and troublesome symptoms experienced by patients is fatigue [11], characterized by a distressing, enduring, and subjective sense of exhaustion or tiredness, affecting both emotional and cognitive aspects, and often disproportionate to their level of activity, significantly interfering with their usual functioning [12]. Fatigue may increase before the start of treatment and typically increases during cancer treatment, including radiation therapy [13], chemotherapy [14], hormonal, and/or biological therapies [15]. This fatigue is associated with different risk factors in cancer patients, for example genetic factors (such as single nucleotide polymorphisms in genes related to inflammation, including the proinflammatory cytokines IL-1\(\beta\), IL-6, and TNF-\(\alpha\)), biological factors (such as alterations in the immune and neuroendocrine systems), psychosocial factors (such as depression, sleep disturbance, loneliness), and behavioral factors (such as physical inactivity and elevated body mass index) [12]. The prevalence of fatigue during treatment ranges from 25% to 99% depending on the population, treatment, and assessment method [11; 16]. Additionally, research suggests that fatigue can predict shorter survival times [17], highlighting its significant impact on quality of life, given its correlation with survival outcomes [18]. In a study with colorectal cancer patients, fatigue was documented as a major cause of reduced quality of life (emotional and cognitive function), with over a third of long-term survivors reporting low quality of life after treatment [19]. Various approaches have been explored to address quality of life and fatigue, encompassing pharmacological, psychological, and exercise interventions. Of all of these, exercise emerges as a particularly promising strategy, with numerous documented benefits observed both during and after its implementation [12; 20].