Author(s): COSENTINO, E., SWARTZ, G.1, CORAZZA, A.2, MARTEGANI, S.1, MARCANTONI, L.1, BOLDRINI, M.1, MANENTE, A.1, DE DONATO, S.1, FORMENTI, D.1, CASTIGLIONI, P.1,3, CAVAGGIONI, L.4,5, RONCHETTI, D.1, MERATI, G.1,3, Institution: SPORT MEDICINE RESIDENCY AT 'UNIVERSITÀ DELL'INSUBRIA', Country: ITALY, Abstract-ID: 2206

INTRODUCTION:
Women who survived breast cancer may often exhibit autonomic cardiovascular regulation dysfunction, characterized by hyperactivation of the sympathetic nervous system, impaired vagal function, reduced aerobic capacity and increased fatigue. We aimed at comparing cardiac autonomic modulation in women who have undergone breast cancer surgery before and after a short training period of adapted rowing.
METHODS:
Seven participants (age 61±7 yrs [m±SD]; height 159±8 cm; weight 59.1±10.9 kg) were enrolled. Autonomic regulation was assessed by analysing standard Heart Rate Variability (HRV: RMSSD, pNN50, HFnu, SNS and PNS) and validated Heart Rate Recovery (HRR: HRR60, HRR120, HRR300 and T30) indexes at rest, during, and after each rowing session, both at baseline and post-5 weeks of training (3 times/week). Perceived exertion was assessed with the Borg scale (6-20) at the end of each workout. Bilateral handgrip strength was also evaluated pre- and post-training.
RESULTS:
Heart rate (HR), recorded in 5 phases of a single workout (sit, stand, warmup, training and recovery), showed similar ​​pre- and post-training values, with significantly lower values reduction at low intensity phases (sit, stand, warmup). The two-way ANOVA revealed a "training" effect near to significance (P=0.09), with a small effect size [ES] (η²=0.046). Regarding HRV, the sympathetic nervous system (SNS) index was not influenced by the training. Conversely, the parasympathetic (PNS) index increased from pre- to post-training (P=0.045; η²=0.077; medium ES). Similarly, other parasympathetic indexes increased: RMSSD (P=0.02; η²=0.048; small ES), pNN50 and HFnu. Post-exercise HRR indexes showed significant improvements or at least positive trend after the training period, with the most marked adaptations in the more rapid indices (HRR60 and T30). Perceived exertion showed a mean value of 11.7±1.5 at baseline and 10.4±1.6 in the post-training (P=0.187; medium ES). Regarding upper limb isometric strength, no significant differences emerged between pre- and post-training, although a positive trend was observed in both limbs (medium ES).
CONCLUSION:
Tendencies toward a reduction in resting HR, improved parasympathetic autonomic modulation (RMSSD, PNS indices, pNN50), and faster cardiac recovery after exercise (HRR60 and T30), indicated greater cardiovascular efficiency, probably due to the amelioration in cardiovascular autonomic control. In addition, a tendency to increased upper limb muscle strength and reduced perception of effort suggests increased resilience and daily functional capacity. Finally, rowing in group contributes to strengthening psychological and social well-being, key aspects for the quality of life in cancer patients. Adapted rowing may represent an effective intervention for women undergoing breast cancer surgery.