Exercise and Endocrine Responses in Humans

( Kazushige Goto ) 한국체육학회 2015 국제스포츠과학 학술대회 Vol.2015 No.1

Comparison of systemic and peripheral responses during high-intensity interval exercise under voluntary hypoventilation vs. hypoxic conditions

Ayano Imai,Keiichi Yamaguchi,Kazushige Goto 한국운동영양학회 2022 Physical Activity and Nutrition (Phys Act Nutr) Vol.26 No.2

[Purpose] This study aimed to determine the systemic and peripheral responses to high-intensity interval exercise (HIIE) with voluntary hypoventilation at low lung volume (VHL) or HIIE under hypoxic conditions. [Methods] Ten male participants completed a single session of HIIE (three sets of 6 × 8-s high-intensity pedaling at 170% of maximal oxygen uptake [VO2max]) under three different conditions: normoxia with normal breathing (NOR: 23 °C, 20.9% of fraction of inspired oxygen [FiO2]), hypoxia with normal breathing (HYP: 23 °C, 14.5% FiO2), and normoxia with VHL (VHL: 23 °C, 20.9% FiO2). A randomized crossover design was used. Power output, arterial oxygen saturation (SpO2), heart rate, and muscle oxygenation were monitored during the exercise and the 16-s recovery. Muscle blood flow (mBF) of the vastus lateralis was also evaluated. [Results] SpO2 during the exercise and the 16-s recovery in the VHL group was significantly lower than in that of the NOR group. However, this parameter in the VHL group was significantly higher than that of the HYP group (NOR: 94.9 ± 0.4%, HYP: 82.8 ± 1.2%, VHL: 90.4 ± 0.5%; p < 0.001). Muscle oxygen saturation was significantly lower in the HYP group than those in the VHL and NOR groups (NOR: 79.6 ± 17.4%, HYP: 65.5 ± 7.7%, VHL: 74.4 ± 7.8%; p = 0.024). No significant difference in this parameter was observed between the VHL and NOR groups (p > 0.05). Additionally, the exercise-induced increase in mBF did not differ significantly among three groups (p > 0.05). [Conclusion] HIIE-induced SpO2 decrease was smaller under hypoxic conditions than during VHL. Moreover, mBF was not enhanced by the addition of VHL during HIIE.

Effects of partial sleep deprivation after prolonged exercise on metabolic responses and exercise performance on the following day

( Aoi Mamiya ),( Ikuhiro Morii ),( Kazushige Goto ) 한국운동영양학회 2021 Physical Activity and Nutrition (Phys Act Nutr) Vol.25 No.1

[Purpose] We determined the effect of partial sleep deprivation (PSD) after an exercise session on exercise performance on the following morning. [Methods] Eleven male athletes performed either a normal sleep trial (CON) or a PSD trial. On the first day (day 1), all subjects performed an exercise session consisting of 90 min of running (at 75% VO_2max) followed by 100 drop jumps. Maximal strength (MVC) was evaluated before and after exercise. In the CON trial, the sleep duration was 23:00-7:00, while in the PSD trial, the sleep duration was shortened to 40% of the regular sleep duration. On the following morning (day 2), MVC, the metabolic responses during 20 min of running (at 75% VO_2max), and time to exhaustion (TTE) at 85% VO_2max were evaluated. [Results] On day 2, neither the MVC nor VO₂ during 20 min of running differed significantly between the two trials. However, the respiratory exchange ratio was significantly lower in the PSD trial than in the CON trial (p = 0.01). Moreover, the TTE was significantly shorter in the PSD trial than in the CON trial (p = 0.01). [Conclusion] A single night of PSD after an exercise session significantly decreased endurance performance without significantly changing muscle strength or cardiopulmonary response.

Irisin response to downhill running exercise in humans

Yoshifumi Tsuchiya,Sahiro Mizuno,Kazushige Goto 한국운동영양학회 2018 Physical Activity and Nutrition (Phys Act Nutr) Vol.22 No.2

[Purpose] To determine the effects of exercise-induced muscle damage, we examined irisin responses during level running (LR), with less muscle damage, and downhill running (DHR), with greater muscle damage under equivalent exercise duration and oxygen consumption (V3O2) conditions. [Methods] Fifteen healthy men (age: 21.6 ± 2.0 y, height: 170 ± 1.3 cm, weight: 64.8 ± 2.7 kg) were randomly assigned to either the LR group (n = 8) or the DHR group (n = 7). Subjects in the LR group performed treadmill running at 70% of maximum oxygen uptake (V3O2max) for 30 min on a 0% gradient. In contrast, subjects in the DHR group performed the same exercise on a –10% gradient. Blood samples were collected before exercise, immediately after exercise, and 1, 3, and 24 h after exercise. [Results] No significant interaction (group × time) or main effect of group or time was observed for changes in plasma irisin concentrations over time (P > 0.05). However, the area under the curve of plasma irisin concentrations during a 3-h post-exercise period was significantly greater in the DHR (239,197 ± 8,166 ng/mL) group than in the LR (92,293 ± 8,755 ng/ml) group (P < 0.05). The blood lactate, serum cortisol, myoglobin, and plasma interleukin-6 concentrations were significantly higher in the DHR group than in the LR group after exercise (P < 0.05 for all variables). [Conclusion] DHR associated with marked muscle damage promoted a greater increase in exercise-induced irisin did LR after the same duration under identical VO2 conditions.

Effects of diet before endurance exercise on hepcidin response in young untrained females

Nanako Hayashi,Aya Ishibashi,Kazushige Goto 한국운동영양학회 2018 Physical Activity and Nutrition (Phys Act Nutr) Vol.22 No.4

[Purpose] We examined the effects of diet before endurance exercise on hepcidin response in young untrained females. [Methods] Ten young untrained females [age: 20.6 ± 0.8 y, height: 157.5 ± 1.0 cm, weight: 54.4 ± 1.5 kg, and maximal oxygen uptake (VO2max): 35.9 ± 1.1 mL/kg/min] were involved in two experimental conditions with a crossover design. The two conditions were separated by approximately 1 month, and each condition was performed during the follicular phase. Subjects completed 60 min of pedaling at 65% of VO2max after consuming a meal (FED) or not consuming a meal (CON). Blood samples were collected before, immediately after, and 3 h after exercise. [Results] Serum ferritin levels before exercise did not differ between the two conditions (P > 0.05). Blood glucose and lactate levels were significantly elevated immediately after exercise only under the FED condition (P < 0.05). Serum iron levels were significantly elevated after exercise under both conditions. However, the plasma interleukin-6 and serum hepcidin levels were not significantly different 3 h after exercise under either condition (P > 0.05). [Conclusion] Consuming a meal before endurance exercise at moderate intensity did not affect exercise-induced hepcidin elevation in young untrained females.

Effects of cold water immersion and compression garment use after eccentric exercise on recovery

Tatsuhiro Maruyama,Sahiro Mizuno,Kazushige Goto 한국운동영양학회 2019 Physical Activity and Nutrition (Phys Act Nutr) Vol.23 No.1

[Purpose] The combined effect of different types of post-exercise treatment has not been fully explored. We investigated the effect of combined cold water immersion (CWI) and compression garment (CG) use after maximal eccentric exercise on maximal muscle strength, indirect muscle damage markers in the blood, muscle thickness, and muscle soreness score 24 h after exercise. [Methods] Ten men performed two trials (CWI + CG and CON) in random order. In the CWI + CG trial, the subjects performed 15 min of CWI (15°C), followed by wearing of a lower-body CG for 24 h after exercise. In the CON trial, there was no post-exercise treatment. The exercise consisted of 6 × 10 maximal isokinetic (60°·s-1) eccentric knee extensions using one lower limb. The maximal voluntary contraction (MVC) and maximal isokinetic (60°·s-1) strength during knee extension, as well as the indirect muscle damage markers, were evaluated before exercise and 24 h after exercise. [Results] The maximal muscle strength decreased in both trials (p < 0.001), with no difference between them. The exercise-induced elevation in the myoglobin concentration tended to be lower in the CWI + CG trial than in the CON trial (p = 0.060). The difference in the MVC, maximal isokinetic strength, muscle thickness, and muscle soreness score between the trials was not significant. [Conclusion] CWI followed by wearing of a CG after maximal eccentric exercise tended to attenuate the exercise-induced elevation of indirect muscle damage markers in the blood.

Effect of long-term carnosine/anserine supplementation on iron regulation after a prolonged running session

Hayashi Nanako,Nagatsuka Haruna,Sato Mikako,Kazushige Goto 한국운동영양학회 2023 Physical Activity and Nutrition (Phys Act Nutr) Vol.27 No.2

[Purpose] Exercise-induced hemolysis, which is caused by metabolic and/or mechanical stress during exercise, is considered a potential factor for upregulating hepcidin. Intramuscular carnosine has multiple effects including antioxidant activity. Therefore, this study aimed to determine whether long-term carnosine/ anserine supplementation modulates exercise-induced hemolysis and subsequent hepcidin elevation. [Methods] Seventeen healthy male participants were allocated to two different groups: participants consuming 1,500 mg/day of carnosine/anserine supplements (n = 9, C+A group) and participants consuming placebo powder supplements (n = 8, PLA group). The participants consumed carnosine/anserine or placebo supplements daily for 30.7 ± 0.4 days. They performed an 80-running session at 70% V4 O pre-and 2peak post-supplementation. Iron regulation and inflammation in response to exercise were evaluated. [Results] Serum iron concentrations significantly increased after exercise (p < 0.01) and serum haptoglobin concentrations decreased after exercise in both groups (p < 0.01). No significant differences in these variables were observed between pre-and post-supplementation. Serum hepcidin concentration significantly increased 180 min after exercise in both groups (p < 0.01). The integrated area under the curve of hepcidin significantly decreased after supplementation (p = 0.011) but did not vary between the C+A and PLA groups. [Conclusion] Long-term carnosine/anserine supplementation does not affect iron metabolism after a single endurance exercise session.

Muscle oxygenation, endocrine and metabolic regulation during lowintensity endurance exercise with blood flow restriction

( Hyejung Hwang ),( Sahiro Mizuno ),( Nobukazu Kasai ),( Chihiro Kojima ),( Daichi Sumi ),( Nanako Hayashi ),( Kazushige Goto ) 한국운동영양학회 2020 Physical Activity and Nutrition (Phys Act Nutr) Vol.24 No.2

[Purpose] The present study investigated the effect of endurance exercise with blood flow restriction (BFR) performed at either 25% maximal oxygen uptake (V3 O2 max) or 40% V3 O2 max) on muscle oxygenation, energy metabolism, and endocrine responses. [Methods] Ten males were recruited in the present study. The subjects performed three trials: (1) endurance exercise at 40% V3 O2 max without BFR (NBFR40), (2) endurance exercise at 25% V3 O2 max with BFR (BFR25), and (3) endurance exercise at 40% V3 O2 max with BFR (BFR40). The exercises were performed for 15 min during which the pedaling frequency was set at 70 rpm. In BFR25 and BFR40, 2 min of pressure phase (equivalent to 160 mmHg) followed by 1 min of release phase were repeated five times (5 × 3 min) throughout 15 minutes of exercise. During exercise, muscle oxygenation and concentration of respiratory gases were measured. The blood samples were collected before exercise, immediately after 15 min of exercise, and at 15, 30, and 60 minutes after completion of exercise. [Results] Deoxygenated hemoglobin (deoxy-Hb) level during exercise was significantly higher with BFR25 and BFR40 than that with NBFR40. BFR40 showed significantly higher total-hemoglobin (total-Hb) than NBFR40 during 2 min of pressure phase. Moreover, exercise-induced lactate elevation and pH reduction were significantly augmented in BFR40, with concomitant increase in serum cortisol concentration after exercise. Carbohydrate (CHO) oxidation was significantly higher with BFR40 than that with NBFR40 and BFR25, whereas fat oxidation was lower with BFR40. [Conclusion] Deoxy-Hb and total Hb levels were significantly increased during 15 min of pedaling exercise in BFR25 and BFR40, indicating augmented local hypoxia and blood volume (blood perfusion) in the muscle. Moreover, low-and moderate-intensity exercise with BFR facilitated CHO oxidation.

Comparison of energy expenditure and substrate oxidation between walking and running in men and women

Akitoshi Makino,Keiichi Yamaguchi,Daichi Sumi,Masaru Ichikawa,Masumi Ohno,Kazushige Goto 한국운동영양학회 2022 Physical Activity and Nutrition (Phys Act Nutr) Vol.26 No.1

[Purpose] The present study compared energy metabolism between walking and running at equivalent speeds during two incremental exercise tests. [Methods] Thirty four university students (18 males, 16 females) were recruited. Each participant completed two trials, consisting of walking (Walk) and running (Run) trials on different days, with 2-3 days apart. Exercise on a treadmill was started from initial stage of 3 min (3.0 k/m in Walk trial, 5.0 km/h in Run trial), and the speed for walking and running was progressively every minute by 0.5 km/h. The changes in metabolic variables, heart rate (HR), and rating of perceived exertion (RPE) during exercise were compared between the trials. [Results] Energy expenditure (EE) increased with speed in each trial. However, the Walk trial had a significantly higher EE than the Run trial at speeds exceeding 92 ± 2 % of the maximal walking speed (MWS, p < 0.01). Similarly, carbohydrate (CHO) oxidation was significantly higher in the Walk trial than in the Run trial at above 92 ± 2 %MWS in males (p < 0.001) and above 93 ± 1 %MWS in females (p < 0.05). [Conclusion] These findings suggest that EE and CHO oxidation during walking increase non-linearly with speed, and walking at a fast speed causes greater metabolic responses than running at the equivalent speed in young participants.