Relationship Between Matrix Metalloproteinases and Tissue Inhibitor of Metalloproteinases Following High-fat Diet and Acute Exercise

Matrix metalloproteinases (MMPs) are involved in the degradation of the extracellular matrix of the tissue and inflammation. Several tissue inhibitors of MMPs (TIMPs) are known to inhibit the activity of MMPs. PURPOSE: The current study investigated the responses of MMP-1, -2, -9, and -10 and TIMP-1, -2, -3, and -4 after a 3-week high-fat, low-carbohydrate (HFLC) diet following an acute aerobic exercise. METHODS: Physically active (unprofessional, competitive marathon runners) male subjects (N=8, age= 39.5 ± 9.9 years) volunteered for the study. Subjects maintained their habitual high carbohydrate (HC) diets before switching to the HFLC diet (70% total caloric intake from fat, not exceeding 50 g of carbohydrates) for 3 weeks. Subjects performed an acute bout of aerobic exercise before and 24 hours after each HC and HFLC diet trial. The exercise protocol consisted of treadmill running at varying paces (personal race paces) for 50 minutes (split into 5, 10-minute periods with 2 minutes of rest in between). Following a 20-minute recovery, subjects additionally performed a 5-km time trial on an outdoor course. Overnight fasting blood samples were collected at pre- and 24-hours post-exercise for each diet trial to analyze changes in MMPs and TIMPs. The data were analyzed using an ANOVA [(HC and HFLC) X (pre- and post-exercise)]. If a significant interaction was found, a Tukey’s post-hoc test was performed (p \u3c 0.05). RESULTS: There was no significant difference in MMPs or TIMPs between the HC and HFLC diet trials, and an acute bout of aerobic exercise did not alter MMPs or TIMPs. There were, however, significant positive correlations between MMP-2 and TIMP-2 (r (14) = 0.51, p = 0.01) and MMP-9 and TIMP-2 (r (14) = 0.49, p = 0.01). Additionally, a significant negative correlation was found between TIMP-4 and MMP-4 (r (14) = -0.57, p = 0.02). CONCLUSION: A relatively short-term high-fat diet and an acute aerobic exercise did not influence serum MMPs or TIMPs in healthy, trained male runners. The activity of MMP-4 may be related to TIMP-4, while the activity of both MMP-2 and -9 may be dependent on TIMP-2. It is highly recommended that future studies focus on examining the effects of a long-term HFLC diet on metabolic pathways of circulating or tissue MMPs and TIMPs in a variety of populations

Resistance Training Recovery: Considerations for Single vs. Multi-joint Movements and Upper vs. Lower Body Muscles

International Journal of Exercise Science 8(1) : 85-96, 2015. This study examined muscle recovery patterns between single-joint (SJ) versus multi-joint (MJ), and upper-body (UB) versus lower-body (LB) exercises and the utility of perceptual measures (ratings of perceived exertion (RPE) and perceived recovery scale (PRS)) to assess recovery status. A 10 rep max (10-RM) was determined for 6 SJ and 4 MJ exercises (5 UB and 5 LB) for male recreational weightlifters (n = 10). Participants completed a baseline protocol including 8 repetitions at 85% of 10-RM followed by a set to failure with 100% of 10-RM. In a counter-balanced crossover design, participants returned at 24 or 48 h to repeat the protocol. PRS and RPE were assessed following the first and second sets of each exercise respectively. Wilcoxon matched pair signed-rank tests determined performance improved (p \u3c 0.05) for every lift type category from 24 to 48 h, but the only difference in ∆ repetitions from baseline at the same time point was between MJ (-1.7 ± 1.5 repetitions ) and SJ (-0.5 ± 1.8 repetitions ) at 24 h (p = 0.037). Higher RPE and lower PRS estimations (p \u3c 0.05) support the utility of perceptual measures to gauge recovery as the only between group differences were also found between MJ and SJ at 24 h. Eighty percent of participants completed within 1 repetition of baseline for all exercises at 48 h except bench press (70%) and deadlift (60%); suggesting 72 h of recovery should be implemented for multi-joint barbell lifts targeting the same muscle groups in slower recovering lifters

Body Image Dissatisfaction: Responses Between Male and Female Exercisers and Non-Exercisers

International Journal of Exercise Science 9(3): 249-257, 2016.Body image dissatisfaction (BID) is defined as the difference between actual and desired image. Body image or BID is subject to high levels of societal pressure and discrepancies are frequent between actual and desired image. This study examined BID among male exercisers (ME), female exercisers (FE), male non-exercisers (MNE) and female non-exercisers (FNE). Further, the potential relationship of personal BID on individual’s beliefs regarding what their peers’ perceptions would be was examined. College-aged men (n = 169) and women (n = 246) used the Stunkard scale to self-assess body image. Participants labeled a) which silhouette they felt accurately represents their body, b) which silhouette they would like to be, c) which silhouette reflects other women’s perception of them and d) which silhouette reflects other men’s perception of them. ANOVA detected a significant difference among groups. Follow up tests revealed less dissatisfaction (score closer to zero) (p \u3c 0.05) for ME (-0.09 + 1.15) than MNE (0.61 + 1.36), FE (0.87 + 0.92) and FNE (1.13 + 1.09) and, less BID for MNE vs. FNE. Specific correlations for anticipated perceptions of male and female peers ranged from 0.05 to 0.27. Current results confirm ME desires to be larger (i.e. muscular) while MNE and females regardless of exercise status desire to be smaller. Although limited by a narrow range of dissatisfaction score, the current study suggests personal body image perceptions are not meaningfully related to what individuals anticipate their peers will think of them

Plasma Glucose and Lipid Profiles Following High-Fat Diet and Acute Aerobic Exercise

PURPOSE: To examine the effects of a 3-week high-fat (HF) diet on plasma glucose, lipids, and lipoproteins following an acute bout of aerobic exercise in middle-aged men. METHODS: Physically active (non-elite, competitive marathon runners), male participants (N=8, age=39.5±9.9 years) volunteered for the study. Participants maintained their habitual high-carbohydrate (HC) diet (60-70% caloric intake from carbohydrate) prior to switching to the HF diet (70% caloric intake from fat, not exceeding 50g of carbohydrates) for 3 weeks. At the end of each diet trial, participants performed an acute bout of aerobic exercise, which consisted of running at varying paces (personal race paces) on a treadmill for 50 minutes (split into 5, 10-minute periods with 2 minutes of rest in between). Following a 20-minute recovery from the treadmill exercise, participants additionally ran a 5-km time trial (average run time = 23.69±2.41 minutes) on an outdoor road course. Overnight fasting blood samples were collected before and 24 hours after exercise for the HC and HF diet trial to analyze glucose, triglyceride (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), lipoprotein(a), very low-density lipoprotein cholesterol (VLDL-C), low-density lipoprotein-cholesterol (LDL-C). The data were analyzed using a two-way ANOVA [2 (diet: HC and HF) X 2 (time: pre and post-exercise)]. Any significant interactions were further analyzed using a Tukey’s post-hoc test. A p-value was set at \u3c 0.05. RESULTS: A glucose level was higher (p=0.046) in the HC diet (96.81±2.45 mg/dL) than the HF diet (89.6±2.45 mg/dL). As compared with the HC diet, the HF diet showed a higher level of TC (142.58±4.75 vs. 171.71±4.75 mg/dL, p=0.001), HDL-C (49.26±3.01 vs. 58.58±3.01 mg/dL, p=0.037), and LDL-C (91.51±4.91 vs. 111.20±4.91 mg/dL, p=0.008), respectively. TG significantly decreased (p=0.03) from 65.68±5.93 to 38.46±5.93 mg/dL at 24 hours of post-exercise. CONCLUSION: The 3-weeks of HF diet modestly increased plasma lipids and lipoproteins within the desirable range. Implementing a relatively short-term HF diet does not appear to significantly elicit negative cardiovascular disease risk markers in non-elite, healthy middle-aged male runners. However, it is strongly recommended for future studies to investigate the safety and beneficial effects of a long-term HF diet on cardiovascular disease risk factors in a variety of population including the untrained

Effects of Caffeine on Repeated Upper/Lower Body Wingates and Handgrip Performance

International Journal of Exercise Science 8(3): 243-255, 2015. Caffeine enhances aerobic performance, but research is equivocal regarding anaerobic performance. This study examined effects of caffeine (7 mg/kg) on anaerobic performance in anaerobically active males (n = 10). Participants completed counterbalanced, double blind caffeine (Caf) and placebo (Pl) trials including a) 6 x 15 s upper body Wingates (UWant), b) 6 x 15 s lower body Wingates (LWant) and c) 6 x15 s maximal effort static hand grip test (HG) with 3 min recovery between bouts, 30 min between exercises. Peak power (Ppeak), mean power (Pmean), and heart rate (HR) as well as perceptual measures included ratings of perceived exertion (RPE), muscle pain perception (MPP), and perceived recovery status (PRS) were recorded per bout. Session RPE (S-RPE) (15 min post) for each exercise mode and trial RPE (T-RPE) [10 min post relative to testing period for each treatment (Caf vs. Pl)]. A series of 2 (trial) x 6 (bout) ANOVA’s assessed differences and Tukey’s LSD post hoc test were used when necessary. Results showed increased performance (main effect) (UWant) for Ppeak (Caf: 6.72 + 1.2 W/kg vs. Pl: 6.41 + 1.0 W/kg); and Pmean (Caf: 5.39 + 0.8 W/kg vs. Pl: 5.18 + 0.8 W/kg); however no significant main effect for LWant or HG was observed. No significant differences were observed for perceptual measures. Caf improved anaerobic performance in repeated UWant (bouts 1-4) but not LWant or HG. Further studies are warranted to examine Caf ergogenic properties in repeated exercises dominated by anaerobic metabolic pathways given the equivocal results

Hydration Efficiency of a Protein Beverage Consumed in a Bolus vs. Metered Pattern during Recovery

International Journal of Exercise Science 13(2): 1476-1486, 2020. This study compared hydration efficiency of a carbohydrate-protein (CHO-PRO) beverage consumed in a bolus (BOL) vs. a metered (MET) drinking pattern during recovery from exercise induced hypohydration. Participants (n = 10) lost 2 - 2.5% of body mass from sweating during a morning exercise session. Participants were then assigned to either consume a carbohydrate/electrolyte/protein beverage in a bolus (BOL) or metered incremental consumption (MET) (counterbalanced) pattern post exercise. Total rehydration beverage administered during recovery equaled 125% of fluid lost during exercise. BOL was administered within the first hour of recovery, MET was administered 25% during the first 30 min, then 12.5% every 30 min for the next 4 hours. Mean (±SD) intake was 2475 ± 324 mL (MET) and 2525 ± 293 mL (BOL) (p = 0.22). Mean urine production was significantly greater for BOL (1167 ml ± 293 ml) than MET (730 ml ± 324 ml) (p = 0.003). Hydration efficiency (fluid ingested vs. fluid retained as percent) was significantly greater for MET (69.1 ± 15.4) than BOL (53.7 ± 9.7) (p = 0.004). Results indicate that, across a ~ 6-hour recovery, a metered drinking pattern improves fluid retention and therefore, hydration efficiency when a carbohydrate-protein beverage is consumed. More research is needed in paradigms characterized by unlimited fluid availability

Hot Training Conditions Inhibit Adequate Ad Libitum Recovery Fluid Intake of Runners

International Journal of Exercise Science 12(6): 1322-1333, 2019. This study examined voluntary fluid intake, hydration descriptors, and sweat loss estimation accuracy following runs in wet bulb globe temperatures of 18 (TEMP) and 26 ºC (HOT). Twelve male runners completed 1-h runs at 65% of VO2 max with access to water during runs and a variety of beverages for the following 24-h. Urine specific gravity (USG), body mass, fluid intake, and urine output were assessed at 12 and 24-h. Runners lost 1.355 ± 0.263 and 1.943 ± 0.485 L during TEMP and HOT, respectively. Sweat loss volume was underestimated by approximately one-third during both conditions. Cumulative fluid intake from start until 1-h post-run was greater in HOT, but not at 12-h (2.202±0.600 vs 2.265±0.673 L) or 24-h (3.602±0.807 vs 3.742±1.205 L). Runners replaced a lower percentage of sweat losses and displayed higher USG (p \u3c 0.001) for HOT (119±34%; 1.027±0.004) versus TEMP (166±51%; 1.018±0.004) at 12-h while exhibiting repeatable rehydration patterns within runners (ICC = 0.89) between trials. Absolute body mass was unable to differentiate the substantial differences in fluid replacement percentage. Seven runners replace

Effects of Caffeine on Perceptually-Based Intensity Production During Outdoor Running

ABSTRACT International Journal of Exercise Science 12(5): 526-535, 2019. Caffeine (CAF) may enhance performance while altering estimated RPE. However, effects of caffeine on RPE production is not well understood. This study examined effects of CAF on velocity (VEL) selection during outdoor running when intensity was prescribed using RPE. Ten (n = 10) fit male runners completed a VO2 max and two running trials, CAF (6 mg· kg-1) vs. placebo (PLA). Participants ran a 2.4 km (1.5 m) bout, at prescribed RPE4, and another at prescribed RPE7, following 10 min passive recovery. Separate 2 (trial) x 6 (time point) repeated measures ANOVA’s compared CAF vs. PLA for VEL and heart rate (HR). No significant main effect was found (CAF vs. PLA) for VEL (m∙min-1) for RPE4 (CAF: 201.7 ± 25.8 vs. PLA: 196.0 ± 17.5) (p = 0.29) or RPE7 (CAF: 236.7 ± 19.5 vs. PLA 231.8 ± 21.3) (p = 0.30). Similarly, no main effect was found (CAF vs. PLA) for HR for RPE4 (CAF: 163 ± 12 vs. PLA: 162 ± 14) (p = 0.69) or RPE7 (CAF: 181 ± 7 vs. PLA: 178 ± 10) (p = 0.31). No significant difference was found for Session-RPE for RPE4 (CAF: 4.0 ± 0.00, PLA: 4.20 ± 0.42) (p = 0.17), however, Session-RPE for RPE7 CAF (7.10± 0.32) was significantly lower than PLA (7.50 ± 0.53) (p = 0.04). While group means show no significant differences, 9 of 20 total trials (45%) were 26 to 104 sec faster for CAF (mean difference = 54 sec) demonstrating improvement in select individuals. Future research should focus on varying responses of individuals to CAF

Effects of Caffeine on Tennis Serve Accuracy

International Journal of Exercise Science 12(6): 1290-1301, 2019. This study examined the effects of caffeine on tennis serve accuracy. Division II tennis athletes (n = 10) completed two serve trials (double-blind, counterbalanced) following ingestion of 6 mg/kg of caffeine or matched placebo an hour prior to data collection. During each tennis serve trial, participants completed 48 non-fault serves divided into 3 sets with 2 serves per 8 different targets. Following each 2 serves per target format, participants completed a shuttle run sprint. Separate 2 (trial) x 8 (targets) repeated measures analysis of variances (ANOVAs) were used for distances from the target center “delta”, and necessary tries for each of the 3 sets. A 2 (treatment) x 3 (set) repeated measures ANOVA was used for shuttle run times. While results were not significant, the treatment main effect approached significance (p = 0.07) in set 2 for the delta of distances when comparing caffeine (96.2 cm ± 19.8) versus placebo (107.1 cm ± 16.3). While there was no significance in sprint times, each sprint was consistently faster following caffeine consumption. Post-trial surveys revealed subjective responses approached significance with greater feelings of stomach distress (p = 0.08) and nervousness (p = 0.13) following caffeine and elevated feeling of fatigue (p = 0.19) following placebo. Therefore, with no impairment in serve accuracy coupled with some evidence of reduced fatigue, results suggest caffeine may benefit tennis athletes. Extending the understanding of the effects of caffeine on tennis serve accuracy and performance could benefit overall match performance, with the potential of improving the match outcome in extended playtime

Four Weeks of Hericium erinaceus Supplementation Does Not Impact Markers of Metabolic Flexibility or Cognition

International Journal of Exercise Science 15(2): 1366-1380, 2022. Hericium erinaceus (HE), also known as Lion’s Mane mushroom, has been found to enhance cognition and metabolic flexibility in various animal models. To date however, only four studies exist in humans and none have evaluated the effects of HE on markers of metabolic flexibility or cognitive performance. A single-blind, placebo controlled, parallel-longitudinal study was used to determine the effects of HE on markers of metabolic flexibility and cognition. Twenty-four participants completed a graded exercise test on a cycle ergometer to analyze substrate oxidation rates and markers of cardiorespiratory fitness. Additionally, two dual-task challenges consisting of a Stroop Word Challenge interspersed with a Mental Arithmetic Challenge were performed, pre-post the graded exercise test, to evaluate markers of cognition in a pre-post fatigued state. Participants were stratified into two groups, receiving either 10 g of HE per day or placebo for 4-weeks in the form of two muffins identical in taste and appearance. Repeated-measures analysis of variance were conducted to evaluate potential interactions or main effects. Although group differences were noted at baseline, there were no significant interactions or main effects observed from HE ingestion for any dependent variable (all p \u3e 0.05). Our data suggest that ingesting 10 g of HE per day for 4-weeks had no impact on metabolic flexibility and cognition in a college-age cohort. Due to the limited research on HE supplementation, future research is needed to establish an effective supplement dose and duration for potential physiological changes to be observed in humans