Impact of Resistance Training Volume on Physical and Perceptual Outcomes of Breast Cancer Survivors Submitted to a Combined Training Program: A Randomized, Single-Blinded Study Chaiane Calonego, 1 Cristine Lima Alberton, 1 Samarita Beraldo Santagnello, 1 Gustavo Zaccaria Schaun, 1 Cristiane Rios Petrarca, 2 Daniel Umpierre, 3 Elisa Gouvêa Portella, 1 Luana Siqueira Andrade, 1 Rochele Barboza Pinheiro, 1 Maria Laura Brizio Gomes, 1 Mariana Silva Häfele, 1 Gabriela Barreto David, 1 Ronei Silveira Pinto, 4 João Saldanha Henkin, 4 and Stephanie Santana Pinto 1 1 Neuromuscular Assessment Laboratory, Physical Education School, Universidade Federal de Pelotas, Pelotas, RS, Brazil; 2 Hospital Escola, Universidade Federal de Pelota, Pelotas, RS, Brazil; 3 Department of Public Health, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; 4 Exercise Research Laboratory, Physical Education School, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil Background: To determine the effect of resistance training volume on physical and perceptual outcomes of breast cancer survivors submitted to a combined training program. Design: Randomized single-blinded study. Methods: Nineteen breast cancer survivor women were randomized to a single-set (SS) or a multiple-set (MS) group. Both groups completed an 8-week combined training intervention in which the SS and MS groups performed 1 and 3 sets per resistance exercise, respectively. The following outcomes were assessed preintervention and postintervention: maximal knee extension dynamic strength (1-repetition maximum), quadriceps muscle thickness, peak oxygen uptake, time to exhaustion, cancer-related fatigue, and quality of life. Results: Both interventions increased knee extension 1-repetition maximum (SS: 29.8% [37.5%]; MS: 19.3% [11.8%]), quadriceps muscle thickness (9.4% [4.1%]; 8.9% [5.9%]), and quality of life (4.3% [6.3%]; 7.9% [9.0%]), with no difference between the groups. However, only MS improved cancer-related fatigue (-2.1% [1.7%]) and time to exhaustion (21.3% [14.9%]), whereas peak oxygen uptake remained unchanged in both groups. Conclusions: Cancer-related fatigue and time to exhaustion, improved only in the MS group after the intervention. On the other hand, similar knee extension 1-repetition maximum, quadriceps muscle thickness, and quality of life improvements were observed in breast cancer survivors irrespective of the resistance training volume performed. Keywords: breast neoplasms, combined training, cancer-related fatigue, quality of life Cancer is considered a threat to public health and one of the leading causes of death worldwide. 1 Among women, breast cancer is responsible for approximately 2 million cases each year, being the most frequent cancer-related cause of death. 2 Breast cancer represents 29.7% of new cancer diagnoses in Brazil, accounting for 66,280 new cases only in 2020. 3 Notwithstanding this, more women survive breast cancer due to medical advances and early detection of the disease. 4 Still, there are considerable long-term side effects related to both cancer and its treatment, which impact aspects of daily living and the quality of life of these individuals. Improving interventions to coun- teract these health problems, therefore, is paramount. Among the side effects related to cancer treatment, patients have marked impairments in muscle strength, 5 power, 6 and peak oxygen uptake (VO 2 peak), 7,8 and an increase in fatigue 9 often due to treatment toxicity. According to Berger et al, 10 fatigue has been reported as one of the main factors leading to functional limitations in patients with a history of breast cancer. As a consequence, breast cancer survivors typically demonstrate lower functional capacity (ie, walking speed) when compared with women of the same age who have never undergone cancer therapy, 6 a condition that has been previously associated with higher all-cause mortality risk in the former. 10 Despite the clear negative impact breast cancer and its treatment has on breast cancer survivors’ health, the impact of rehabilitation physical exercise programs in this clinical population remains under- explored. Some studies 11,12 have shown that combined training, herein defined as the inclusion of resistance and aerobic exercises in the same session, can improve VO 2 peak, muscle strength, cancer- related fatigue, and quality of life. These outcomes were found to mediate the improvements observed in functional capacity in breast cancer survivors. 11,12 However, multiple-set (MS) resistance training protocols typically employed in these studies (ie, 3 sets, 8–12 repetitions with ≈80% of 1-repetition maximum [1RM]) may repre- sent a challenge for breast cancer survivors due to their lower functional capacity compared with women who have never under- gone cancer treatment. 6,13 Calonego https://orcid.org/0000-0002-4132-1148 Alberton https://orcid.org/0000-0002-5258-9406 Santagnello https://orcid.org/0000-0001-6261-2086 Schaun https://orcid.org/0000-0003-3339-714X Petrarca https://orcid.org/0000-0001-6828-0756 Umpierre https://orcid.org/0000-0001-6953-0163 Portella https://orcid.org/0000-0002-1446-6747 Andrade https://orcid.org/0000-0003-3819-0690 Pinheiro https://orcid.org/0000-0001-5081-3083 Gomes https://orcid.org/0000-0002-5110-5529 Häfele https://orcid.org/0000-0002-9011-1366 David https://orcid.org/0000-0001-6886-5690 Henkin https://orcid.org/0000-0003-2909-1543 Pinto https://orcid.org/0000-0002-5827-5723 S.S. Pinto (tetisantana@yahoo.com.br) is corresponding author, https:// orcid.org/0000-0003-4555-2717 204 Journal of Physical Activity and Health, 2023, 20, 204-216 https://doi.org/10.1123/jpah.2022-0097 © 2023 Human Kinetics, Inc. ORIGINAL RESEARCH Unauthenticated | Downloaded 05/05/23 09:08 AM UTC