The impact of high-intensity interval training exercise on breast cancer survivors: a pilot study to explore fitness, cardiac regulation and biomarkers of the stress systems

Abstract

Background Cardiovascular disease (CVD) remains the largest cause of death in breast cancer survivors. The aim of this study was to explore the impact of exercise intensity on aerobic fitness and autonomic cardiac regulation (heart rate variability (HRV)) and salivary biomarkers of the stress systems (HPA-axis, cortisol; sympathetic nervous system, α-amylase) and mucosal immunity (secretory(s)-IgA), markers of increased risk of CVD in breast cancer survivors. Methods Participants were randomly assigned to; 1) high intensity interval training (HIIT); 2) moderate-intensity, continuous aerobic training (CMIT); or 3) a wait-list control (CON) for a 12-week (36 session) stationary cycling intervention. Cardiorespiratory fitness (VO 2peak ), resting HRV and salivary biomarkers were measured at baseline 2–4 d pre-intervention and 2–4 d post the last exercise session. Results Seventeen participants were included in this study (62 ± 8 years, HIIT; n = 6, CMIT; n = 5, CON; n = 6). A significant improvement ( p ≤ 0.05) was observed for VO 2peak in the HIIT group; 19.3% (B = 3.98, 95%CI = [1.89; 4.02]) and a non-significant increase in the CMIT group; 5.6% (B = 1.96, 95%CI = [− 0.11; 4.03]), compared with a 2.6% (B = − 0.64, 95%CI = [− 2.10; 0.82]) decrease in the CON group. Post intervention improvements in HRV markers of vagal activity (log (ln)LF/HF, LnRMSSD) and sympathetic nervous system (α-amylase waking response) occurred for individuals exhibiting outlying (> 95% CI) levels at baseline compared to general population. Conclusion High intensity interval training improved cardiovascular fitness in breast cancer survivors and improved cardiac regulation, and sympathetic nervous system (stress) responses in some individuals. High-intensity interval training was safe and effective for breast cancer survivors to participate in with promising results as a time efficient intensity to improve physical health and stress, reducing CVD risk. Trial registration This pilot study was retrospectively registered through the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12620000684921 .

Effects of a Home-Based Lifestyle Intervention Program on Cardiometabolic Health in Breast Cancer Survivors during the COVID-19 Lockdown

“…In addition, cholinergic mechanisms within the inflammatory reflex have, in recent years, been implicated in attenuating obesity-related inflammation and metabolic complications. Recent evidence highlights the relationship among fitness, the autonomic nervous system and metabolic dysfunctions in BC, and their impact on the patient’s prognosis [ 91 ].…”

“…Overweight and inactivity are also associated with chronic low-grade inflammation and metabolic dysfunction characterized by elevated levels of circulating proinflammatory mediators known to promote tumorigenesis and recurrences [ 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 ]. Indeed, metabolic syndrome accompanied by sedentary behaviors associated with being overweight have been established as notable risk factors for BCSs [ 99 , 100 ].…”

The Effects of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Inflammatory Markers, Body Composition, and Physical Fitness in Overweight/Obese Survivors of Breast Cancer: A Randomized Controlled Clinical Trial

“…The participants' peak power was determined using the maximal incremental cycle test prior to the 12-week intervention. Exercise intensity over the duration of the study was adjusted to ensure participants in the MICT group exercised within the prescribed range of 55-65% of peak power or the equivalent of between 9 and 13 on the modified Borg scale (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) as determined by the study investigators. The HIIT group similarly completed 5 min warm-up and cool-down periods at 50% peak power as determined by the pre-intervention maximal incremental cycle exercise test.…”

“…Prior research has demonstrated a strong correlation between increased cardiorespiratory fitness (VO2 peak ) and reduced cancer-related mortality [8]. Although current guidelines for cancer survivors recommend the performance of moderate-intensity aerobic exercise [9,10], recent evidence indicates that high-intensity interval training (HIIT) more effectively improves VO 2peak compared to moderate-intensity continuous training (MICT) in BC survivors (BCS) [11]. This dose-response relationship was illustrated well through the work of Jones et al [12], where MICT was unable to elicit significant alterations in plasma concentrations of IL-6, CRP, or TNF-α in BCS.…”

Acute and Chronic Effects of Interval Training on the Immune System: A Systematic Review with Meta-Analysis

“…The intensity of HIIT protocols was prescribed and controlled based on percentage of maximal velocity achieved during incremental test (Vmax) [ [41,66] or reserve heart rate HR reserve [42], and percentage of peak power [25,26,44,51,58] or maximum anaerobic power [27]. Eleven studies prescribed SIT protocol using "all out" efforts [22][23][24]44,45,47,48,[52][53][54]63]. Characteristics of IT protocols are detailed in Tables 1 and 2.…”