applied sciences Article Energy Expenditure during Acute Weight Training Exercises in Healthy Participants: A Preliminary Study Muhammad Adeel 1,2, Chien-Hung Lai 3,4, Chun-Wei Wu 2, Jiunn-Horng Kang 3,4, Jian-Chiun Liou 2, Hung-Chou Chen 3,5 , Meng-Jyun Hong 2 and Chih-Wei Peng 1,2,6,* 1 International PhD Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 110, Taiwan; [email protected] 2 School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 110, Taiwan; [email protected] (C.-W.W.); [email protected] (J.-C.L.); [email protected] (M.-J.H.) 3 Department of Physical Medicine and Rehabilitation, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; [email protected] (C.-H.L.); [email protected] (J.-H.K.); [email protected] (H.-C.C.) 4 Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, Taipei 110, Taiwan 5 Department of Physical Medicine and Rehabilitation, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235, Taiwan 6 School of Gerontology Health Management, College of Nursing, Taipei Medical University, Taipei 110, Taiwan * Correspondence: [email protected]; Tel./Fax: +886-2-2736-1661 (ext. 3070) Abstract: Energy expenditure during weight training exercises produces great fitness and health benefits for humans, but few studies have investigated energy expenditure directly during weight training. Therefore, in this study, we aimed to determine energy costs during three training sessions Citation: Adeel, M.; Lai, C.-H.; Wu, consisting of three different exercises. Ten participants were randomly allocated into two groups: C.-W.; Kang, J.-H.; Liou, J.-C.; Chen, an untrained (n = 5, with no weight training experience) and a trained group (n = 5, with some H.-C.; Hong, M.-J.; Peng, C.-W. weight training experience). Each participant completed three training sessions on separate days. Energy Expenditure during Acute Weight Training Exercises in Healthy While wearing a mask for indirect calorimetric measurements, each participant participated in Participants: A Preliminary Study. training sessions conducted with three dumbbell exercises: the bent-over row, deadlift, and lunge. Appl. Sci. 2021, 11, 6687. https:// Metabolic equivalents (METs), energy expenditure (EE), respiratory exchange ratio (RER), heart rate doi.org/10.3390/app11156687 (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and rate of perceived exertion (RPE) were measured. The total energy cost was calculated from the oxygen consumption (VO2) Academic Editors: Alessandra during each exercise. Our results showed that the METs of a single training session were 3.3 for the Durazzo and Wojciech Kolanowski untrained group and 3.4 for the trained group, while the sum of the EE was 683–688 and 779–840 kcal, respectively. The physiological parameters, such as heart rate (p = 0.001 *) for the lunge and rate of Received: 5 June 2021 perceived exertion (p = 0.005 *) for the bent-over row, changed significantly in both groups. It was Accepted: 19 July 2021 concluded that the exercise protocol of this study involved a moderate intensity of 2.4–3.9 METs. The Published: 21 July 2021 energy cost of each training exercise was between 179 and 291 kcal. Publisher’s Note: MDPI stays neutral Keywords: weight training; acute exercises; METs; energy expenditure with regard to jurisdictional claims in published maps and institutional affil- iations. 1. Introduction Weight training is an important type of exercise for the elderly, general, and athletic Copyright: © 2021 by the authors. populations and is used to enhance body composition along with other aspects of health Licensee MDPI, Basel, Switzerland. and performance [1,2]. More specifically, it can reduce body fat, lower blood pressure, This article is an open access article enhance cholesterol levels, promote glycemic control, and generally decrease the risk of distributed under the terms and heart disease [3,4]. As weight training is included as one of the main exercise programs to conditions of the Creative Commons increase energy expenditure (EE), it should target the large major muscle groups [4–6]. The Attribution (CC BY) license (https:// recommended dose of weight training exercise for a healthy life for all age groups is two or creativecommons.org/licenses/by/ more days per week [4]. 4.0/). Appl. Sci. 2021, 11, 6687. https://doi.org/10.3390/app11156687 https://www.mdpi.com/journal/applsci Appl. Sci. 2021, 11, 6687 2 of 11 Total EE (TEE) is composed of the basal metabolic rate (BMR or basal EE (BEE)) and is equivalent to approximately 60–75% of TEE, activity EE (AEE) is about 15–30% of TEE, and dietary thermogenesis is about 10% of TEE [7,8]. TEE, BEE, and AEE vary over time and differ between sexes, with values for males often higher than those of females, and values for older people are lower than those for younger people [9]. Different disease conditions may have an effect on TEE and AEE [10]. In addition, since the AEE is the most variable component of TEE, it is often used to assess TEE [11–13]. Doubly labeled water is the gold standard to assess TEE because of its high degree of accuracy, and indirect calorimetry is commonly used to track EE in healthy and diseased people over time [14] during physical activity. The metabolic equivalent (MET) is a functional unit of oxygen consumption during exercise [15–17]. According to the Centers for Disease Control and Prevention (CDC)/ American College of Sports Medicine (ACSM) and the Compendium of Physical Activities, 1.6–2.9 METs is considered light intensity, 3.0–5.9 METs is considered moderate inten- sity, and >6.0 METs is considered vigorous intensity of aerobic exercise [1,18]. Resistance training (RT) is described as 3.5 METs (code 02054) and/or 5.0 METs (code 02052) in the Compendium of Physical Activities [18], with EE ranging from 5 to 10 kcal/min (for men of an average height and weight, this is equivalent to 135–270 kcal). Previous research [15–17] focused on RT using a training machine and/or free weights with high loads. Moderate- intensity exercises using dumbbells, such as the bent-over row, deadlift, and lunge can be performed as free weight exercises. In the previous literature, many studies have reported the EE of acute or chronic resistance exercise, but to our best knowledge, no study has compared energy costs and physiological profiles of the dumbbell bent-over row, deadlift, and lunge exercises together with rest intervals in one training session. As these exercises use multiple groups of large muscles in the upper and lower body, they may provide benefits of fitness and muscle gain. In addition, this study focused on healthy individuals’ weight training so that EEs could be compared between two populations of naive and experienced weightlifters to generalize the study findings for healthy and athletic populations. In RT, pulling or pushing is usually performed rapidly, but in this study, the same speed of 2 s was used for the pulling and pushing phases. In addition, dumbbells serve as free weights with a higher degree of freedom and increased challenge to exercised muscles. Therefore, the main objectives of this study were twofold: (1) to compare the energy cost of each weight training exercise (the dumbbell bent-over row, deadlift, and lunge) between the two groups to determine if the exercises belong to moderate or high intensity at 60% of one-repetition maximum (RM) loading and (2) to compare physiological parameters during these three weight training exercises. The results of this study can be used to determine an exercise protocol that can be utilized for fitness and conditioning purposes in healthy populations. 2. Materials and Methods Participant Recruitment: A single-blinded controlled study was conducted at Taipei Medical University Hospital, and the protocol was approved by the TMU Joint Institutional Review Board (IRB no.: N202004023). The trial was registered at ClinicalTrials.gov (accessed on 1 June 2021) (NCT04532905). Initially, 13 young male participants were recruited and allocated into two groups between July 2020 and February 2021 through convenience sampling. Among these participants, three were excluded. Thus, five participants were included in the untrained group (with no weight training experience) and trained group (with 2 months of weight training experience). Each participant signed a written consent form before the start of the study. The inclusion criteria were: (1) healthy male individuals of 20–40 years of age; (2) no metabolic, systematic, or musculoskeletal disease or injury; (3) no recent surgical procedure that could limit exercise training; (4) taking no medications, especially sedatives, antidepressants, antihypertensive, etc.; and (5) physically fit according to the Physical Activity Readiness Questionnaire (PAR-Q) [19]. The exclusion criteria were a diagnosis of any metabolic, systematic, or musculoskeletal disease; an injury; or a recent Appl. Sci. 2021, 11, 6687 3 of 11 surgery (Figure1). Functional outcome measurements and data analyses were performed by trained research staff who were not involved in the intervention. Participants were blinded to their groups in this study. Figure 1. Study Flow Diagram. Experimental procedure: Each participant visited the training room, where testing and data collection were completed, for five separate sessions. All participants were instructed to eat a meal 2–4 h before testing, to avoid alcohol and caffeine ingestion for 24 h before testing, and to refrain from strenuous exercise for 24–48 h before testing [20]. Session 1: During the first visit, baseline body weight (kg), height (cm), body mass index (BMI), and body fat percentage were measured using a Karada Scan-371 body scale (Omron, Kyoto, Japan). Each participant was evaluated using the PAR-Q for physical fitness, and the testing and training procedures were explained to them by an expert researcher.