Low-Load and High-Load Resistance Exercise Completed to Volitional Fatigue Induce Increases in Postexercise Metabolic Responses With More Prolonged Responses With the Low-Load Protocol.

ABSTRACT: Grisebach, D, Bornath, DPD, McCarthy, SF, Jarosz, C, and Hazell, TJ. Low-load and high-load resistance exercise completed to volitional fatigue induce increases in post-exercise metabolic responses with more prolonged responses with the low-load protocol. J Strength Cond Res 38(8): 1386-1393, 2024-Comparisons of high-load with low-load resistance training (RT) exercise have demonstrated no differences in postexercise metabolism when volume is matched. This important limitation of matching or equating volume diminishes benefits of the low-load RT protocol. Therefore, the purpose of this study was to determine the effects of acute low-load high volume and high-load low volume RT protocols completed to volitional fatigue on postexercise metabolism. Eleven recreationally active resistance-trained male subjects (24 ± 2 years; BMI: 25.3 ± 1.5 kg·m -2 ) completed 3 experimental sessions: (a) no-exercise control (CTRL); (b) RT at 30% 1 repetition maximum (1RM; 30% 1RM); and (c) RT at 90% 1RM (90% 1RM) with oxygen consumption (V̇ o2 ) measurements 2 hours postexercise. The RT sessions consisted of 3 sets of back squats, bench press, straight-leg deadlift, military press, and bent-over rows to volitional fatigue completed sequentially with 90 seconds of rest between sets and exercises. Changes were considered important if p < 0.100 with a ≥medium effect size. V̇ o2 1 hour postexercise was elevated following 30% 1RM (25%; p = 0.003, d = 1.40) and 90% 1RM (14%; p = 0.010, d = 1.15) vs. CTRL and remained elevated 2 hours postexercise following 30% 1RM (16%; p = 0.010, d = 1.15) vs. CTRL. Total O 2 consumed postexercise increased following 30% 1RM and 90% 1RM (∼17%; p < 0.044, d > 0.91) vs. CTRL. Fat oxidation was elevated 1 hour postexercise following 30% 1RM and 90% 1RM (∼155%; p < 0.001, d > 2.97) and remained elevated 2 hours postexercise following 30% 1RM compared with CTRL and 90% 1RM (∼69%; p < 0.030, d > 1.03). These data demonstrate beneficial changes to postexercise metabolism following high- and low-load RT sessions, with more prolonged effects following the low-load RT protocol completed to volitional fatigue.

Low- and high-load resistance training exercise to volitional fatigue generate exercise-induced appetite suppression.

Research on exercise-induced appetite suppression often does not include resistance training (RT) exercise and only compared matched volumes. PURPOSE: To compare the effects of low-load and high-load RT exercise completed to volitional fatigue on appetite-regulation. METHODS: 11 resistance-trained males (24 ± 2 y) completed 3 sessions in a crossover experimental design: 1) control (CTRL); 2) RT exercise at 30% 1-repetition maximum (RM); and 3) RT exercise at 90% 1-RM. RT sessions consisted of 3 sets of 5 exercises completed to volitional fatigue. Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), active peptide tyrosine (PYY), lactate, and subjective appetite perceptions were measured pre-exercise, 0-, 60-, and 120-min post-exercise. Energy intake was recorded the day before, of, and after each session. RESULTS: Lactate was elevated following both 30% (0-, 60-, 120-min post-exercise) and 90% (0-, 60-min post-exercise; P < 0.001, d > 3.92) versus CTRL, with 30% greater than 90% (0-min post-exercise; P = 0.011, d = 1.14). Acylated ghrelin was suppressed by 30% (P < 0.007, d > 1.22) and 90% (P < 0.028, d > 0.096) post-exercise versus CTRL, and 30% suppressed concentrations versus 90% (60-min post-exercise; P = 0.032, d = 0.95). There was no effect on PYY (P > 0.171, ηp2 <0.149) though GLP-1 was greater at 60-min post-exercise in 90% (P = 0.052, d = 0.86) versus CTRL. Overall appetite was suppressed 0-min post-exercise following 30% and 90% versus CTRL (P < 0.013, d > 1.10) with no other differences (P > 0.279, d < 0.56). There were no differences in energy intake (P > 0.101, ηp2 <0.319). CONCLUSIONS: RT at low- and high-loads to volitional fatigue induced appetite suppression coinciding with changes in acylated ghrelin though limited effects on anorexigenic hormones or free-living energy intake were present.

Intense interval exercise induces greater changes in post-exercise metabolism compared to submaximal exercise in middle-aged adults.

INTRODUCTION: High-intensity interval training (HIIT) and sprint interval training (SIT) consistently elevate post-exercise metabolism compared to moderate-intensity continuous training (MICT) in young adults (18-25 years), however few studies have investigated this in middle-aged adults. PURPOSE: To assess the effect of exercise intensity on post-exercise metabolism following submaximal, near-maximal, and supramaximal exercise protocols in middle-aged adults. METHODS: 12 participants (8 females; age: 44 ± 10 years; V ˙ O2max: 35.73 ± 9.97 mL·kg-1 min-1) had their oxygen consumption ( V ˙ O2) measured during and for 2 h following 4 experimental sessions: (1) no-exercise control (CTRL); (2) MICT exercise (30 min at 65% V ˙ O2max); (3) HIIT exercise (10 × 1 min at 90% maximum heart rate with 1 min rest); and (4) modified-SIT exercise (8 × 15 s "all-out" efforts with 2 min rest). Between session differences for V ˙ O2 and fat oxidation were compared. RESULTS: O2 consumed post-exercise was elevated during the 1st h and 2nd h following HIIT (15.9 ± 2.6, 14.7 ± 2.3 L; P < 0.036, d > 0.98) and modified-SIT exercise (16.9 ± 3.3, 15.30 ± 3.4 L; P < 0.041, d > 0.96) compared to CTRL (13.3 ± 1.9, 12.0 ± 2.5 L) while modified-SIT was also elevated vs HIIT in the 1st h (P < 0.041, d > 0.96). Total post-exercise O2 consumption was elevated following all exercise sessions (MICT: 27.7 ± 4.1, HIIT: 30.6 ± 4.8, SIT: 32.2 ± 6.6 L; P < 0.027, d > 1.03) compared to CTRL (24.9 ± 4.1 L). Modified-SIT exercise increased fat oxidation (0.103 ± 0.019 g min-1) compared to all sessions post-exercise (CTRL: 0.059 ± 0.025, MICT: 0.075 ± 0.022, HIIT: 0.081 ± 0.021 g·min-1; P < 0.007, d > 1.30) and HIIT exercise increased compared to CTRL (P = 0.046, d = 0.87). CONCLUSION: Exercise intensity has an important effect on post-exercise metabolism in middle-aged adults.

Intense interval exercise induces lactate accumulation and a greater suppression of acylated ghrelin compared with submaximal exercise in middle-aged adults.

Exercise in young adults (18-25 yr) suppresses appetite in a dose-response relationship with exercise intensity. Although several mechanisms have been proposed to explain this response, lactate is the most well established. To date, no study has investigated this specifically in middle-aged adults where the appetite response to a meal is different. To explore the effects of submaximal, near maximal, and supramaximal intensity exercise on appetite regulation in middle-aged adults. Nine participants (age: 45 ± 10 yr) completed four experimental sessions: 1) no-exercise control (CTRL); 2) moderate-intensity continuous training [MICT; 30 min, 65% maximal oxygen consumption (V̇o2max)]; 3) high-intensity interval training (HIIT; 10 × 1 min efforts, 90% heart rate maximum, 1 min recovery); and 4) sprint interval training (SIT; 8 × 15 s "all-out" efforts, 2 min recovery). Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), active peptide tyrosine tyrosine (PYY), lactate, and subjective appetite perceptions were measured pre-exercise, 0-, 30-, and 90-min postexercise. Energy intake was recorded the day before and day of each session. Acylated ghrelin was suppressed (P < 0.001, [Formula: see text] = 0.474) by HIIT (0-min and 30-min postexercise; P < 0.091, d > 1.84) and SIT (0-min, 30-min, and 90-min postexercise; P < 0.037, d > 1.72) compared with CTRL, and SIT suppressed concentrations compared with MICT (0-min and 30-min postexercise; P < 0.91, d > 1.19). There were no effects of exercise on active PYY, active GLP-1, appetite perceptions, or free-living energy intake (P > 0.126, [Formula: see text] < 0.200). Intense interval exercise that generates lactate accumulation suppresses acylated ghrelin with little effect on anorexigenic hormones, overall appetite, or free-living energy intake.NEW & NOTEWORTHY We explored the effects of submaximal, near maximal, and supramaximal intensity exercise on appetite regulation in middle-aged adults. Our data support the intensity-dependent effect of exercise on acylated ghrelin suppression that is closely related to lactate accumulation, though there appears to be little effect on anorexigenic hormones [active peptide tyrosine tyrosine (PYY), active glucagon-like peptide-1 (GLP-1)], overall appetite, or free-living energy intake. These data support previous results in younger adults where lactate was implicated in the exercise-induced suppression of acylated ghrelin.

Similar Postexercise Hypotension After MICT, HIIT, and SIT Exercises in Middle-Age Adults.

INTRODUCTION: Acute bouts of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) transiently lower systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the hours after termed postexercise hypotension (PEH); however, the effects of sprint interval training (SIT) exercise have yet to be explored in middle-age adults. Although previous work has found no effect of exercise intensity on PEH, no study has compared submaximal, near maximal, and supramaximal intensities, specifically in middle-age adults where blood pressure (BP) management strategies may be of greater importance. PURPOSE: This study examined the effects of MICT, HIIT, and SIT exercises on PEH in the immediate (≤2 h) and 24 h after exercise specifically in middle-age adults. METHODS: Fourteen participants (10 female; age, 46 ± 9 yr; SBP, 116 ± 11 mm Hg; DBP, 67 ± 6 mm Hg; one hypertensive, four prehypertensive, nine normotensive) had their BP measured before, immediately (15, 30, 60, 120 min), and over 24 h after four experimental sessions: 1) 30-min MICT exercise (65% maximal oxygen consumption), 2) 20-min HIIT exercise (10 × 1 min at 90% maximum heart rate with 1-min rest), 3) 16-min SIT exercise (8 × 15 s all-out sprints with 2-min rest), and 4) no-exercise control. Postexercise BP was compared with no-exercise control. RESULTS: PEH was similar for all exercise sessions for SBP ( P = 0.388, = 0.075) and DBP ( P = 0.206, = 0.108). Twenty-four-hour average SBP was similar for all sessions P = 0.453, = 0.069), and DBP was similar over 24 h except after MICT exercise compared with HIIT exercise ( P = 0.018, d = 1.04). CONCLUSIONS: In middle-age adults, MICT, HIIT, and SIT exercises are effective at reducing SBP; however, the effects on DBP are smaller, and neither reductions are sustained over 24 h.