Albumin is an important factor in the control of serum free fatty acid flux in both male and female mice.

Albumin knockout (Alb-/-) mice exhibit a low plasma free fatty acid (FFA) concentration, but it was not known if the suppressed concentration reflects a lower rate of appearance (Ra) of FFA in the circulation (i.e., lower FFA flux) or if the absence of albumin alters the relationship between FFA flux and concentration. For understanding the role of albumin in FFA transport through the bloodstream, it is not sufficient to rely on FFA concentration data alone. Therefore, we developed a method to study FFA kinetics in Alb-/- mice. Using an albumin-free formulation of [U-13C]palmitate tracer, serum FFA kinetics were tested in Alb-/- and wild-type (WT) mice. Results indicate that the flux of FFA in serum of Alb-/- mice was significantly lower than in WT mice (P < 0.05), while albumin deficiency did not alter the relationship between FFA flux and concentration. Next, to test if suppressed lipolysis might have also been involved in the suppressed FFA kinetics, gene expression of a lipolytic enzyme (adipose triglyceride lipase, Atgl) and a marker of lipolysis (phosphorylation of hormone-sensitive lipase, p-HSL) were measured in adipose tissue. In contrast to the low FFA flux in Alb-/-, both Atgl gene expression and p-HSL protein were significantly higher in adipose tissue of Alb-/- than in WT mice (P < 0.05). Thus, the low FFA flux in Alb-/- appeared to be driven by the absence of albumin's FFA binding functions rather than through regulation of lipolysis, indicating that albumin is an important factor in determining the flux of FFA in circulation.NEW & NOTEWORTHY To improve understanding of the albumin protein's function in vivo, we tested plasma free fatty acid kinetics in albumin knockout mice compared with wild-type mice. Using a new tracer formulation strategy, it was discovered that the appearance rate of free fatty acids in serum is lower in albumin knockout mice than in wild-type mice. The results indicate that albumin is a major controller of free fatty acid kinetics.

Performance evaluation of different albumin assays for the detection of analbuminemia.

Analbuminemia is characterized by the near absence of albumin in the plasma. Different methods are available for measuring albumin levels, but they do not necessarily agree with one another. It is a concern that analbuminemic samples could be falsely characterized due to the incorrect estimation of albumin. The objective of the work was to evaluate the performance of different assays in detecting analbuminemia. Albumin knockout (Alb-/-) mouse plasma was used to test the suitability of different albumin assays for their ability to properly characterize extreme albumin deficiency. Bromocresol green (BCG), bromocresol purple (BCP), enzyme-linked immunosorbent assay (ELISA), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and gel electrophoresis were tested. The LC-MS/MS assay exhibited broad coverage of the amino acid sequence of albumin and indicated 8,400-fold lower (P<0.0001) albumin expression in Alb-/- than wildtype (WT), demonstrating its suitability for identifying extreme albumin deficiency. ELISA estimated albumin at 1.5±0.1 g/dL in WT and was below the detection limit in all Alb-/- samples. Gel electrophoresis yielded consistent results with LC-MS/MS and ELISA. The BCG assay overestimated albumin with apparently appreciable albumin concentrations in Alb-/- mice, yet the assay still indicated a significant difference between genotypes (Alb-/-, 1.2±0.05 g/dL, WT, 3.7±0.1 g/dL, P<0.0001). BCP drastically overestimated albumin and could not successfully identify the known analbuminemic phenotype of Alb-/- mice. By using Alb-/- plasma as a reference material and LC-MS/MS as a reference method, ELISA and gel electrophoresis appear appropriate for identifying analbuminemia, while BCG and BCP are not suitable. It is concluded that dye-binding assays should be avoided when extreme hypoalbuminemia or analbuminemia is suspected.

The lactate response to a second bout of exercise is not reduced in a concurrent lower-limb exercise program.

We aimed to evaluate the blood lactate level in response to two bouts of exercise. First, we hypothesized that blood lactate elevation in response to moderate-intensity aerobic exercise (MIAE) would be lower at the end of the second bout of MIAE than the first bout of MIAE. In this context, we also hypothesized that lactate accumulation at the end of resistance exercise (RE) would be reduced if MIAE is performed before RE (i.e., concurrent exercise; CE). If so, we hypothesized that the order of the CE (i.e., RE + MIAE vs. MIAE + RE) influences blood lactate kinetics. To test the hypotheses, forty-three healthy men participated in three studies. In study 1, 20 men (age 21 ± 2 years) performed two bouts of a 20-min MIAE separated by a 20-min rest interval. In study 2, 11 men (age 22 ± 1 years) performed RE only and CE (MIAE + RE; ARCE) with a 20-min rest interval in a crossover design. In study 3, 12 men (age 21 ± 2 years) performed both CEs, which were ARCE and RE + MIAE (RACE), with a 20-min rest interval in a crossover design. We measured blood lactate before and at the end of each exercise session. In study 1, the blood lactate response to the second bout of MIAE was lower than that of the first bout (P < 0.001, r = 0.68). However, the blood lactate response to the ARCE trial was not lower than the response to the RE trial in study 2 (P = 0.475, r = 0.22). The results of study 3 showed that the RACE and ARCE trials induced a similar lactate response (MIAE P = 0.423, r = 0.28; RE P = 0.766, d = 0.03). These observations indicate that whereas lactate accumulation might be diminished by a second bout of MIAE, a different type of exercise (i.e., aerobic/resistance) did not result in a diminished lactate accumulation in response to a second bout of exercise.

Essential amino acid supplements ingestion has a positive effect on executive function after moderate-intensity aerobic exercise.

Aerobic exercise acutely improves cognitive function (e.g., executive function (EF); memory recognition (MR)) and increases circulating brain-derived neurotrophic factor (BDNF). In addition, branched-chain amino acids (BCAA) ingestion acutely shortens the choice reaction time and increases brain BDNF. We examined whether the ingestion of essential amino acid (EAA) supplements (mainly composed of BCAA) would positively impact on cognitive function and circulating BDNF after moderate-intensity aerobic exercise. Twenty-two healthy young men received either an EAA supplements or the placebo (PL) 30 min before undergoing aerobic exercise. The participants performed a cycling exercise at 60% of peak oxygen uptake for 30 min. EF after aerobic exercise was better after the EAA treatment than after the PL treatment (P = 0.02). MR (P = 0.38 for response accuracy; P = 0.15 for reaction time) and circulating BDNF (P = 0.59) were not altered by EAA supplements. EF improvement was correlated with increases in some amino acids (leucine, isoleucine, valine, lysine, phenylalanine; all Ps < 0.05) that are potential substrates for synthesizing neurotransmitters in the brain. These results suggest that EAA supplements ingestion had a positive effect on EF after moderate-intensity aerobic exercise, while MR and BDNF were not altered.

Ergogenic Effects of Very Low to Moderate Doses of Caffeine on Vertical Jump Performance.

Although the ergogenic effects of 3-6 mg/kg caffeine are widely accepted, the efficacy of low doses of caffeine has been discussed. However, it is unclear whether the ergogenic effects of caffeine on jump performance are dose responsive in a wide range of doses. This study aimed to examine the effect of very low (1 mg/kg) to moderate doses of caffeine, including commonly utilized ergogenic doses (i.e., 3 and 6 mg/kg), on vertical jump performance. A total of 32 well-trained collegiate sprinters and jumpers performed countermovement jumps and squat jumps three times each in a double-blind, counterbalanced, randomized, crossover design. Participants ingested a placebo or 1, 3, or 6 mg/kg caffeine 60 min before jumping. Compared with the placebo, 6 mg/kg caffeine significantly enhanced countermovement jump (p < .001) and squat jump (p = .012) heights; furthermore, 1 and 3 mg/kg of caffeine also significantly increased countermovement jump height (1 mg/kg: p = .002, 3 mg/kg: p < .001) but not squat jump height (1 mg/kg: p = .436, 3 mg/kg: p = .054). There were no significant differences among all caffeine doses in both jumps (all p > .05). In conclusion, even at a dose as low as 1 mg/kg, caffeine improved vertical jump performance in a dose-independent manner. This study provides new insight into the applicability and feasibility of 1 mg/kg caffeine as a safe and effective ergogenic strategy for jump performance.

Acute Effect of Caffeine Supplementation on 100-m Sprint Running Performance: A Field Test.

PURPOSE: No study has assessed the acute effect of caffeine supplementation on 100-m sprint running in athletics and caffeine's net ergogenicity on 100-m sprint running remains unclear. We investigated the acute effects of caffeine supplementation on 100-m sprint running performance in a field test. METHODS: Thirteen male collegiate sprinters were subjected to 100-m sprint running time trials (TT) after the ingestion of 6 mg·kg -1 body weight caffeine or placebo supplementation in a double-blind, counterbalanced, randomized, and crossover design. Sprint velocity was measured with a laser system, and sprint time was calculated from the data in which the effects of environmental factors that would act as confounding factors on sprint time during TT were eliminated. RESULTS: The corrected 100-m sprint time was significantly shortened by 0.14 s with caffeine supplementation compared with placebo (placebo: 11.40 ± 0.39 s, caffeine: 11.26 ± 0.33 s; P = 0.007, g = -0.33). The corrected sprint time up to 60 m during TT was also significantly shorter with caffeine supplementation than with placebo ( P = 0.002). Furthermore, the mean sprint velocity for splits of 0-10 and 10-20 m was significantly increased by caffeine supplementation (all P < 0.05). CONCLUSIONS: Acute caffeine supplementation enhanced the corrected 100-m sprint time by improving the sprint performance in the first 60 m after more explosive acceleration in the early stage of the acceleration phase. Thus, for the first time, we directly demonstrated caffeine's ergogenicity on 100-m sprint performance in athletics.

Effects of Maca on Muscle Hypertrophy in C2C12 Skeletal Muscle Cells.

With aging, sarcopenia and the associated locomotor disorders, have become serious problems. The roots of maca contain active ingredients (triterpenes) that have a preventive effect on sarcopenia. However, the effect of maca on muscle hypertrophy has not yet been investigated. The aim of this study was to examine the effects and mechanism of maca on muscle hypertrophy by adding different concentrations of yellow maca (0.1 mg/mL and 0.2 mg/mL) to C2C12 skeletal muscle cell culture. Two days after differentiation, maca was added for two days of incubation. The muscle diameter, area, differentiation index, and multinucleation, were assessed by immunostaining, and the expression levels of the proteins related to muscle protein synthesis/degradation were examined by Western blotting. Compared with the control group, the muscle diameter and area of the myotubes in the maca groups were significantly increased, and the cell differentiation index and multinucleation were significantly higher in the maca groups. Phosphorylation of Akt and mTOR was elevated in the maca groups. Maca also promoted the phosphorylation of AMPK. These results suggest that maca may promote muscle hypertrophy, differentiation, and maturation, potentially via the muscle hypertrophic signaling pathways such as Akt and mTOR, while exploring other pathways are needed.

Impact of Inter-Set Short Rest Interval Length on Inhibitory Control Improvements Following Low-Intensity Resistance Exercise in Healthy Young Males.

The length of rest interval between sets (i.e., inter-set rest interval) is an important variable for resistance exercise program. However, the impact of the inter-set rest interval on improvements in cognitive function following resistance exercise remains unknown. In this study, we compared the effect of short rest interval (SRI) vs. long rest interval (LRI) protocols on post-exercise cognitive inhibitory control (IC) improvements induced by low-intensity resistance exercise. Twenty healthy, young males completed both SRI and LRI sessions in a crossover design. The bilateral knee extensor low-intensity resistance exercise was programed for six sets with 10 repetitions per set using 40% of one-repetition maximum. The inter-set rest interval lengths for SRI and LRI protocols were set for 1 and 3min, respectively. The color-word Stroop task (CWST) was administrated at six time points: baseline, pre-exercise, immediate post-exercise, and every 10min during the 30-min post-exercise recovery period. The levels of blood lactate, which may be an important determinant for improving IC, throughout the 30-min post-exercise recovery period were significantly higher following SRI protocol than following LRI protocol (p=0.002 for interaction effect). In line with this result, large-sized decreases in the reverse-Stroop interference score, which represent improved IC, were observed immediately after SRI protocol (d=0.94 and 0.82, respectively, vs. baseline and pre-exercise) as opposed to the moderate-sized decreases immediately after LRI protocol (d=0.62 and 0.66, respectively, vs. baseline and pre-exercise). Moreover, significant decreases in the reverse-Stroop interference score were observed from 10 to 30min after SRI protocol (all ps<0.05 vs. baseline and/or pre-exercise), whereas no such decrease was observed after LRI protocol. Furthermore, the degree of decreases in the reverse-Stroop interference score throughout the 30-min post-exercise recovery period was significantly greater in SRI protocol than in LRI protocol (p=0.046 for interaction effect). We suggest that the SRI protocol is more useful in improving post-exercise IC, potentially via greater circulating lactate levels, compared to the LRI protocol. Therefore, the inter-set rest interval length may be an important variable for determining the degree of cognitive function improvements following resistance exercise in healthy young males.

Exercise adherence-related perceptual responses to low-load blood flow restriction resistance exercise in young adults: A pilot study.

Resistance exercise (RE) with blood flow restriction (BFR) is recognized as a beneficial strategy in increasing skeletal muscle mass and strength. However, the effects of BFR on changes in perceptual parameters, particularly those related to exercise adherence, induced by RE are not completely understood. In this study, we examined the exercise adherence-related perceptual responses to low-load BFR-RE. Sixteen young males performed both BFR and non-BFR (NBFR) sessions in a crossover design. The bilateral knee extensor low-load RE was performed with a standard BFR-RE protocol, consisting of four sets (total 75 repetitions), using 20% of one-repetition maximum. BFR-RE was performed with 200 mmHg pressure cuffs placed around the proximal region of the thighs. NBFR-RE was performed without pressure cuffs. The ratings of perceived exertion and leg discomfort measured using the Borg's Scales were higher for BFR-RE session than for NBFR-RE session (both p < 0.001 for interaction effect). The Feeling Scale-measured affect and Task Motivation Scale-measured task motivation were lower for BFR-RE session than for NBFR-RE session (both p < 0.05 for interaction effect); by contrast, the Numerical Rating Scale-measured perceived pain was higher for BFR-RE session than for NBFR-RE session (p < 0.001 for interaction effect). The Physical Activity Enjoyment Scale-measured enjoyment immediately after RE was lower with BFR than with NBFR (p < 0.001). These findings suggest that BFR exacerbates the exercise adherence-related perceptual responses to low-load RE in young males. Therefore, further studies are needed to develop effective strategies that minimize the BFR-RE-induced negative effects on perceptual responses.

Similar improvements in cognitive inhibitory control following low-intensity resistance exercise with slow movement and tonic force generation and high-intensity resistance exercise in healthy young adults: a preliminary study.

This study compared the effects of low-intensity resistance exercise with slow movement and tonic force generation (ST-LRE) and high-intensity resistance exercise (HRE) on post-exercise improvements in cognitive inhibitory control (IC). Sixteen young males completed ST-LRE and HRE sessions in a crossover design. Bilateral knee extensor ST-LRE and HRE (8 repetitions/set, 6 sets) were performed with 50% of one-repetition maximum with slow contractile speed and 80% of one-repetition maximum with normal contractile speed, respectively. The IC was assessed using the color-word Stroop task at six time points: baseline, pre-exercise, immediate post-exercise, and every 10 min during the 30-min post-exercise recovery period. The blood lactate response throughout the experimental session did not differ between ST-LRE and HRE (condition × time interaction P = 0.396: e.g., mean ± standard error of the mean; 8.1 ± 0.5 vs. 8.1 ± 0.5 mM, respectively, immediately after exercise, P = 0.983, d = 0.00). Large-sized decreases in the reverse-Stroop interference scores, which represent improved IC, compared to those before exercise (i.e., baseline and pre-exercise) were observed throughout the 30 min post-exercise recovery period for both ST-LRE and HRE (decreasing rate ≥ 38.8 and 41.4%, respectively, all ds ≥ 0.95). The degree of post-exercise IC improvements was similar between the two protocols (condition × time interaction P = 0.998). These findings suggest that despite the application of a lower exercise load, ST-LRE improves post-exercise IC similarly to HRE, which may be due to the equivalent blood lactate response between the two protocols, in healthy young adults.

Effect of very low-intensity resistance exercise with slow movement and tonic force generation on post-exercise inhibitory control.

BACKGROUND: The extremely low loads (e.g., <30% of one-repetition maximum) involved in performing resistance exercise are effective in preventing musculoskeletal injury and enhancing exercise adherence in various populations, especially older individuals and patients with chronic diseases. Nevertheless, long-term intervention using this type of protocol is known to have little effects on muscle size and strength adaptations. Despite this knowledge, very low-intensity resistance exercise (VLRE) with slow movement and tonic force generation (ST) significantly increases muscle size and strength. To further explore efficacy of ST-VLRE in the clinical setting, this study examined the effect of ST-VLRE on post-exercise inhibitory control (IC). METHODS: Twenty healthy, young males (age: 21 ± 0 years, body height: 173.4 ± 1.2 cm, body weight: 67.4 ± 2.2 kg) performed both ST-VLRE and normal VLRE in a crossover design. The load for both protocols was set at 30% of one-repetition maximum. Both protocols were programmed with bilateral knee extension for six sets with ten repetitions per set. The ST-VLRE and VLRE were performed with slow (3-sec concentric, 3-sec eccentric, and 1-sec isometric actions with no rest between each repetition) and normal contractile speeds (1-sec concentric and 1-sec eccentric actions and 1-sec rests between each repetition), respectively. IC was assessed using the color-word Stroop task at six time points: baseline, pre-exercise, immediate post-exercise, and every 10 min during the 30-min post-exercise recovery period. RESULTS: The reverse-Stroop interference score, a parameter of IC, significantly decreased immediately after both ST-VLRE and VLRE compared to that before each exercise (decreasing rate >32 and 25%, respectively, vs. baseline and/or pre-exercise for both protocols; all Ps < 0.05). The improved IC following ST-VLRE, but not following VLRE, remained significant until the 20-min post-exercise recovery period (decreasing rate >48% vs. baseline and pre-exercise; both Ps < 0.001). The degree of post-exercise IC improvements was significantly higher for ST-VLRE than for VLRE (P = 0.010 for condition × time interaction effect). CONCLUSIONS: These findings suggest that ST-VLRE can improve post-exercise IC effectively. Therefore, ST-VLRE may be an effective resistance exercise protocol for improving cognitive function.

Association between plantar flexor muscle volume and dorsiflexion flexibility in healthy young males: ultrasonography and magnetic resonance imaging studies.

BACKGROUND: Although joint flexibility is important for human locomotion, the determinants of joint flexibility are not fully understood. In this study, we examined the relationship between dorsiflexion flexibility and plantar flexor muscle size in healthy young males. METHODS AND RESULTS: The dorsiflexion flexibility was assessed using range of motion (ROM) and stiffness during active and passive dorsiflexion. Active ROM was defined as the maximal angle during voluntary dorsiflexion. Passive ROM was defined as the angle at the onset of pain during passive dorsiflexion. Passive stiffness was calculated as the slope of the linear portion of the torque-angle curve between 10º and 20º dorsiflexion of the ankle during passive dorsiflexion. In the first study, the plantar flexor muscle volume (MV) in 92 subjects was estimated on the basis of the lower leg length and plantar flexor muscle thickness, as measured using ultrasonography. The estimated plantar flexor MV correlated significantly with active ROM (r = -0.433), passive ROM (r = -0.299), and passive stiffness (r = 0.541) during dorsiflexion (P = 0.01 for all). In the second study, the plantar flexor MV in 38 subjects was measured using magnetic resonance imaging. The plantar flexor MV correlated significantly with plantar flexor active ROM (r = -0.484), passive ROM (r = -0.383), and passive stiffness (r = 0.592) during dorsiflexion (P = 0.05 for all). CONCLUSIONS: These findings suggest that a larger plantar flexor MV is related to less dorsiflexion flexibility in healthy young males.

Blood Flow Restriction Improves Executive Function after Walking.

PURPOSE: Blood flow restriction (BFR) walking is recognized as a beneficial strategy for increasing skeletal muscle mass and strength. No study has examined the effect of BFR exercise on cognitive functions, including executive function (EF). In this study, we examined the effect of BFR walking on EF. METHODS: We performed two studies, at rest and exercise, with BFR or non-BFR (NBFR) in a crossover design. Sitting rest was performed for 15 min (study 1, n = 8). Exercise was programmed at five sets of 2-min walking at 5 km·h with 1-min rest intervals (study 2, n = 16). The BFR condition was achieved using 200 mm Hg pressure cuffs placed around the proximal region of the thighs. The NBFR condition involved no pressure cuffs. EF was assessed using the color-word Stroop task before and after each condition. RESULTS: In study 1, there were no significant effects on EF parameters for both BFR and NBFR conditions, suggesting that BFR alone does not improve EF. In study 2, incongruent reaction time shortened after BFR walking compared with that before walking (P = 0.001). Furthermore, the reverse Stroop interference score decreased after BFR walking compared with that before walking (P < 0.001). CONCLUSION: These findings suggest that, even with a mild exercise, BFR walking improves EF independently of the effect of BFR alone or walking alone.

Negative effects of blood flow restriction on perceptual responses to walking in healthy young adults: A pilot study.

BACKGROUND: Blood flow restriction (BFR) exercise is recognized as a beneficial strategy in increasing skeletal muscle mass and strength. These positive effects can also be obtained by a mild exercise mode such as walking. However, BFR exacerbates some perceptual responses, such as perceived exertion response, induced by exercise. Despite this knowledge, the negative effects of BFR exercise on major perceptual parameters related to exercise adherence remain unknown. Furthermore, compared with other exercise modes (e.g., resistance exercise), little is known regarding the effects of BFR on perceptual responses to walking. To clarify these issues, we examined the effects of BFR walking on perceptual parameters, including exercise adherence-related parameters. METHODS: Eighteen healthy, young males performed both BFR and non-BFR (NBFR) walking on a treadmill in a crossover design. Exercise was performed as five sets of 2-min walking with 1-min rest intervals. BFR walking was performed with 200 mmHg pressure cuffs placed around the proximal region of the thighs. NBFR walking was performed without pressure cuffs. RESULTS: Ratings of perceived exertion and leg discomfort were significantly higher during BFR walking than during NBFR walking. Affect and task motivation were significantly lower during BFR walking than during NBFR walking; by contrast, perceived pain was significantly higher during BFR walking than during NBFR walking. Enjoyment immediately after walking was significantly lower with BFR than with NBFR. CONCLUSIONS: These findings suggest that BFR walking induces greater responses of perceptual parameters, including exercise adherence-related parameters, than does NBFR walking. Therefore, BFR walking may decrease adherence to this exercise. To further popularize BFR exercise, further studies are needed to develop effective strategies to minimize the BFR-induced negative effects on perceptual responses.

Effect of repeated bouts versus a single bout of moderate-intensity exercise on postexercise inhibitory control.

We previously demonstrated that duration of aerobic exercise plays an important role in improving cognitive inhibitory control (IC). Repeated bouts of aerobic exercise (R-EX), which are performed with a rest interval, is a useful strategy in improving physical health parameters in similar manners to a single bout of aerobic exercise (S-EX). However, whether R-EX would be effective in improving IC remains unknown. This study compared the effect of R-EX versus S-EX of moderate-intensity exercise on postexercise IC. Twenty healthy, young males performed both R-EX and S-EX in a crossover design. R-EX consisted of two 20-min moderate-intensity bouts (60% of peak oxygen consumption) for 20 min, which were separated by a 20-min rest interval. S-EX consisted of a once-off 40-min moderate-intensity bout without rest interval. To evaluate IC, the color-word Stroop task was administered before exercise, immediately after exercise, and every 10 min during the 30-min postexercise recovery period. The reverse-Stroop interference score, which is a parameter of IC, significantly decreased immediately after both R-EX and S-EX compared with that before each exercise (both Ps < 0.05). The degree of changes in IC following exercise did not differ between the two protocols. By contrast, the results of the present study showed that R-EX may have more beneficial effects on cardiac and perceptual responses than S-EX. Therefore, the present study determined that R-EX changes postexercise IC similar to S-EX. We suggest that R-EX can be used as safe and effective exercise protocol to improve cognitive function in various populations.

Work volume is an important variable in determining the degree of inhibitory control improvements following resistance exercise.

We previously determined that improvement in cognitive inhibitory control (IC) immediately after localized resistance exercise was greater for high-intensity resistance exercise (HRE) than for low-intensity resistance exercise (LRE). However, our previous study used the same total repetitions (i.e., same repetitions per set) between HRE and LRE; therefore, the difference in postexercise IC improvement might be due to a difference in work volume (i.e., intensity × total repetitions). In this study, we compared the effect of high-volume (HV)-LRE to that of volume-matched HRE on postexercise IC improvements. Twenty-two healthy, young males performed both HV-LRE and HRE in a crossover design. Exercise loads for HV-LRE and HRE were set at 35% and 70% of one-repetition maximum, respectively. The bilateral knee extension exercises for HV-LRE and HRE were programmed for six sets with 20 and 10 repetitions, respectively, per set. IC was measured using the color-word Stroop task (CWST) at six time points; baseline, pre-exercise, immediate postexercise, and every 10 min during the 30-min postexercise recovery period. The reverse-Stroop interference score decreased significantly immediately after HV-LRE and HRE compared with that before each exercise (decreasing rate >34 and >38%, respectively, vs. baseline and pre-exercise; all ps < .05), and the decreased score remained significant until 20 min after both protocols (decreasing rate >40 and >38%, respectively, vs. baseline and pre-exercise; all ps < .05). The degree of the postexercise IC improvements did not differ significantly between the two protocols. These findings suggest that HV-LRE improves IC in a similar manner to volume-matched HRE.