## 4 Discussion
In the present study, HR values increased in both groups, but this increase was higher for the untrained group (111-137 ppm) than for the trained group (115-123 ppm) for all three exercises during weight training sessions because untrained group participants conducted the training sessions at comparatively low loads and had no experience with weight training. However, the lunge exercise significantly increased the HR in both training groups (\(p\) = 0.001 *). One study explained a possible mechanism for the increase in HR during circuit resistance training (CRT) at a moderate intensity (40% 1 RM loading). The authors explained that anaerobic factors during CRT resulted in higher HRs. High forces of contraction may impede blood flow because of the squeezing effect of themuscles on the blood vessels. The reduced blood flow to the exercising muscles probably restricts the transport of the required oxygen to the mitochondria and the elimination of metabolic end-products [29]. However, as CRT progresses, metabolites (such as lactate and hydrogen ions) accumulate, causing a rise in HR above the point where oxygen is required. In addition, greater activation of neurological receptors increases tachycardia [30]. In this study, SBP increased after 60% 1 RM of each exercise in both groups, ranging from 135 to 146 mmHg. In comparison with the untrained group (135-142 mmHg), the trained group (136-146 mmHg) showed a slightly higher SBP for the bent-over row and deadlift exercises, but the lunge exercise resulted in an SBP of 142.60 \(\pm\) 16.93 for the untrained group and 136.40 \(\pm\) 19.07 for the trained group without reaching significance. The reason for this increase may have been the fact that when exercise is begun, the body is not well prepared for exercise loads and compensates by increasing the SBP, but after performing the two exercises, the SBP did not increase much because the body had adjusted to the training loads. On the other hand, the untrained group showed a greater DBP for all three exercises (72-77 mmHg) than the trained group (70-75 mmHg) without attaining significance. A previous study reported that blood pressure increased after a 95% of 1 RM weightlifting session for 90 min in professional bodybuilders [29]. The greater pressure was noted during a double leg press, with mean values of 320/250 and 255/190 mmHg for arm curls when repetitions were continued to failure. This increase in blood pressure may have possibly been due to (a) mechanical compression of blood vessels; (b) a potent reflex pressure response; or (c) a Valsalva response to the arm curls, overhead press, and single and double leg presses [31]. There has been little research into the EE (in kcal) during non-circuit training exercises. One study reported total energy costs during a single-set, eight-exercise protocol of 135.20 \(\pm\) 16.6 kcal for men and 81.7 \(\pm\) 11.1 kcal for women. However, according to ACSM guidelines, to meet the MET threshold of moderate-intensity, a volume ranging from 150-200 kcal is required for health benefits for endurance-type activities [16]. From our study, the energy costs of each exercise during a single training session are presented in Table 3. The bent-over row EE values were 176-186 and 213-277 kcal (\(p\) = 0.050 *) and the deadlift EE values were 238-245 and 271-282 kcal (\(p\) = 0.001 *), while the lunge EE values were 253-263 and 278-291 kcal (\(p\) = 0.006 *) for the untrained and trained groups, respectively. The EE values were higher for the trained group because of RM loading and differences in weight training experience. However, overall during each training session, both the untrained and trained groups consumed 679-840 kcal (\(p\) = 0.004 *). Another study measured EE in kiljoules (kJ) for bench press and back squat exercises in a single training session with 60% of 1 RM training load, and each participant performed three sets of 10 repetitions at a speed of 3 s down and 1 s up.