Validation of a novel multi-exercise approach to isometric resistance training in normotensive adults

European Journal of Applied Physiology https://doi.org/10.1007/s00421-025-05785-3 ORIGINAL ARTICLE Validation of a novel multi‑exercise approach to isometric resistance training in normotensive adults Ben H. Wright1 · Peter G. W. Jones2 · Mark R. Antrobus3 · Anthony W. Baross4 Received: 10 October 2024 / Accepted: 26 March 2025 © Crown 2025 Abstract Purpose Short- to long-term isometric resistance training (IRT) can produce clinically meaningful reductions in resting blood pressure, but established methods are costly or require laboratory access. An affordable method could improve accessibility; however, there is a need to establish efficacy and safety prior to prescription as an alternative IRT method. This study aims to determine whether a novel isometric training band (ITB) can elicit cardiovascular (CV) responses (blood pressure [BP] and heart rate [HR]) comparable with those of established methods. Methods Fifteen normotensive adults (systolic [sBP]; 120 ± 3 mmHg, diastolic [dBP]; 71 ± 6 mmHg) completed a single 2-min isometric handgrip contraction (IHG) at 30% maximal voluntary contraction (MVC) followed by 2-min contractions for four individual ITB exercises at a self-determined intensity to replicate perceived exertion (CR-10) during IHG. A further 15 normotensive participants (sBP; 118 ± 6 mmHg, dBP; 68 ± 7 mmHg) completed bouts of IRT (IHG, 4 × 2 min at 30% MVC; ITB, 4 × 2 min at imposed CR-10 values [4–5]), with CV responses compared between bouts. Results No differences in BP responses were detected between IHG and each ITB exercise (P > 0.05). CR-10 values and HRs were comparable between the individual IHG contraction and three ITB exercises (P > 0.05). Between bouts, regulating contraction intensity through imposed CR-10 values resulted in comparable BP responses (P > 0.05). Conclusion These findings suggest that a novel ITB and associated protocol may serve as versatile, inclusive, and accessible alternative method for performing IRT. Keywords Isometric exercise · Blood pressure · Handgrip · CR- 10 scale · Heart rate · Rate pressure product Abbreviations ANOVA Analysis of variance BP Blood pressure BPM Beats per minute CR- 10 Category-ratio scale Communicated by Ellen Adele Dawson. * Ben H. Wright 1 School of Sport, Nutrition and Allied Health Professions, Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, UK 2 Glasgow Caledonian University, Glasgow, Scotland 3 School of Education, Childhood, Youth & Sport, Faculty of Wellbeing, Education and Language Studies, The Open University, Milton Keynes, UK 4 Centre for Physical Activity and Life Sciences, Faculty of Art, Science and Technology, University of Northampton, Northamptonshire, UK COV Coefficient of variation CV Cardiovascular DBP Diastolic blood pressure LOA Limits of agreement MVC Maximum voluntary contraction MBP Mean arterial pressure MIN Minute MMHG Millimeters of mercury MV02 Myocardial oxygen consumption ICC Intraclass correlation coefficient IHG Isometric handgrip IRT Isometric resistance training ITB Isometric training band RPP Rate pressure product S Seconds SBP Systolic blood pressure Vol.:(0123456789) European Journal of Applied Physiology Introduction Hypertension is a leading global preventable risk factor for all-cause mortality and cardiovascular-related disease (Zhou et al. 2021), with worldwide prevalence projected to affect 1.6 billion adults by the year 2025 (Kearney et al. 2005). As cardiovascular (CV) diseases are the leading cause of worldwide mortality (Cesare et al. 2024) with ischemic heart disease, cerebrovascular disease, and chronic kidney disease attributed to increased systolic blood pressure (sBP, ≥ 140 mmHg) (Bundy et al. 2017; Mills et al. 2020; Webb and Werring 2022), efficacious prevention, treatment, and management approaches are needed to address this global public health challenge. Modifications to lifestyle behaviors (diet, weight loss, reduced sodium consumption, and increased physical activity) form the initial management approaches of international hypertension guidelines (Unger et al. 2020; Whelton et al. 2018; Williams et al. 2018). Participation in physical activity and exercise are well-established interventions to reduce blood pressure (BP) (Islam et al. 2023; Naci et al. 2019; Noone et al. 2020) with aerobic exercise the preferentially recommended training mode (Ghadieh and Saab 2015). However, adherence to physical activity guidelines (150 min of moderate-intensity aerobic physical activity per week) remains low in adults (Guthold et al. 2016) and is further reduced for those with chronic conditions such as hypertension (Lopes et al. 2021). Thus, alternative, adherable, and accessible approaches are warranted. Isometric resistance training (IRT) is an established non-pharmacologic approach in hypertension management (Edwards et al. 2024) given the reduced time requirements (~ 8 min per session, 24 min per week) and effectiveness of reducing resting and ambulatory BP irrespective of hypertensive status (Awuah and Dieberg 2023; Hansford et al. 2021; Smart et al. 2019) may serve as an complementary or alternative to traditionally prescribed aerobic exercise. Despite the potential benefits, there remains a reluctance for the wider prescription of IRT (Mancia et al. 2023). Acute bouts of exercise increase BP to meet tissue metabolic demands with this response exaggerated during isometric exercise (Greaney et al. 2015). Thus, safety concerns persist for broader application of IRT given a pronounced BP response to exercise is associated with cardiac events (Pescatello et al. 2015). However, comparable acute CV responses are observed between isometric exercise and dynamic resistance training (Kounoupis et al. 2020) when utilising low contraction intensities (30% maximal voluntary contraction). Studies have identified differing modes of IRT may elicit non-comparable BP responses, especially those of larger muscle mass (Coneglian et al. 2023a, b). Therefore, it is imperative that acute responses to novel IRT approaches are examined, and suitable methods are designed to regulate the CV response especially for methods utilising multiple and large muscle groups. Effective IRT interventions have implemented various exercise modes, with isometric handgrip (IHG) completed thrice weekly (4 × 2-min contractions) at 30% of an individual’s maximum voluntary contraction (MVC), the most widely studied protocol (Smart et al. 2019). While alternatives such as bilateral leg extension exhibit BP-lowering capabilities (Baross et al. 2022; Inder et al. 2016; Wiles et al. 2010), this approach requires expensive, inaccessible, and non-portable equipment in addition to the requirement of repeat laboratory visits, compromising the time efficiency of IRT and imposing economic and accessibility participation barriers. Novel alternative IRT methods have been established, including the IsoBall (Baddeley-White et al. 2019) and (...truncated)