Citrus Aurantium and caffeine complex versus placebo on biomarkers of metabolism: a double blind crossover design

BACKGROUOND: The purpose of this study was to examine resting the metabolic response to the ingestion of a complex containing Citrus Aurantium + Caffeine (CA + C) and if its consumption influences metabolic recovery following a high-intensity anaerobic exercise bout in habitual caffeine users. METHODS: Ten physically active males (25.1 ± 3.9 years; weight 78.71 ± 9.53 kg; height 177.2 ± 4.6 cm; body fat 15.5 ± 3.13%) participated in this study. This study was performed in a double-blind, randomized crossover fashion consisting of two exhaustive exercise protocols. On each visit the participants consumed either a CA + C (100 mg of CA and 100 mg of C) or placebo (dextrose) capsule. After consumption, participants were monitored throughout a 45-min ingestion period, then completed a repeated Wingate protocol, and were then monitored throughout a 45-min recovery period. Metabolic function was measured through blood glucose, plasma insulin, plasma triglycerides, and plasma catecholamines: epinephrine (E) and norepinephrine (NE). Biomarkers were taken at four different time points; Ingestion period: baseline (I1), post-ingestion period (I2); Recovery period: immediately post-exercise (R1), post-recovery period (R2). RESULTS: A repeated measures ANOVA revealed significant time-dependent increases in plasma E and NE at I2 only in the CA + C trial (p \u3c 0.05), and a significant decrease in blood glucose at I2 in the PLA trial (p \u3c 0.05); however, no meaningful changes in glucose was observed following CA + C ingestion. No changes in insulin or triglycerides were observed during the ingestion period. No trial-dependent differences were observed in the Recovery period. All biomarkers of metabolic recovery were equivalent when evaluating R1 v R2. Participants recovered in a similar time-dependent manner in all markers of metabolism following the PLA and CA + C trials. CONCLUSION: The findings of this study suggested that normal recommended dosages of 100 mg CA + 100 mg C is sufficient to promote glucose sparing at rest, with modest increases in SNS activity; however, the individual role of CA or C in this response cannot be determined

Physical Fitness Responses after Sixteen Weeks of Three Fitness Program Trainings in Untrained Subjects

International Journal of Exercise Science 17(4): 54 - 72, 2024. The remarkable popularity of fitness trends like high intensity functional training (HIFT), choreographed high intensity classes (CHIC) and resistance (RT) trainings raises the question on their effect on cardio-respiratory, lactate removal rate, endurance and body composition responses. The purpose of this study was to assess and compare these effects. Ninety-five participants were randomly assigned into 16 weeks of these trainings, five sessions/week. Anthropometric and fitness tests were carried out before training (PRE), after eight (8W) and sixteen weeks (16W). Body composition measures demonstrated significant decrease in body fat percentage (p\u3c0.001, d=0.17–0.54) for all groups and fat mass (p\u3c 0.001, d= 0.26–0.53) for HIFT and CHIC in 8W,16W and in 16W for RT (p= 0.03 , d= 0.14), also significant increase in fat free mass only in HIFT (p\u3c 0.002, d= 0.06–0.21) and RT (p\u3c 0.001, d= 0.17–0.33) in 8W,16W. Cardio-respiratory measures demonstrated significant improvements in maximal aerobic capacity for HIFT (p\u3c 0.001, d= 0.58–1.26) and CHIC (p\u3c 0.001, d= 0.45–1.21) in 8W,16W. Endurance tests demonstrated significant improvements in 8W,16W in aerobic endurance among HIFT (p\u3c 0.001 , d= 1.28–3.19) and CHIC (p\u3c 0.001 , d= 1.16–1.79), in muscle absolute endurance in three groups (p\u3c 0.002, d= 0.14–1.17)and muscle relative endurance in HIFT (p\u3c 0.02, d= 0.13–0.2)and RT (p= 0.03, d= 0.3) in 16W. We can conclude that HIFT and CHIC are effective for cardio–respiratory and endurance improvement and all three programs are effective in reducing body fa

Metabolic biomarkers following a short and long bout of high-intensity functional training in recreationally trained men

Glucose regulation is a fundamental process of metabolic function, and is acutely altered by physical activity. High-Intensity Functional Training (HIFT) is a form of exercise performed using combinations of various modalities and durations. It is unknown if the metabolic responses to HIFT are similar to more commonly studied modalities (e.g., cycling and treadmill exercise), or if exercise duration will influence glucose regulation. The purpose of this study was to determine the effect of a Short (0.05), except for lowered 3HR E (p=0.007). This study demonstrated that both SHORT and LONG bouts of HIFT elicited GLU, INS, E, and NE responses similar to those reported in response to high-intensity treadmill and cycling exercise, and that duration of the HIFT bouts may not be a determining factor in glucose regulation in healthy individuals

The Influence of Citrus urantium and Caffeine Complex versus Placebo on the Cardiac Autonomic Response: A Double Blind Crossover Design

Background: The purpose of this study was to examine the resting cardiac autonomic nervous system’s response to the ingestion of a complex containing Citrus aurantium + Caffeine (CA + C) and its influence on recovery following a high-intensity anaerobic exercise bout in habitual caffeine users. Methods: Ten physically active males (25.1 ± 3.9 years; weight 78.71 ± 9.53 kg; height 177.2 ± 4.6 cm; body fat 15.5 ± 3.13%) participated in this study, which consisted of two exhaustive exercise protocols in a randomized crossover design. On each visit the participants consumed either a CA + C (100 mg of CA and 100 mg of C) or placebo (dextrose) capsule. After consumption, participants were monitored throughout a 45-min ingestion period, then completed a repeated Wingate protocol, and were then monitored throughout a 45-min recovery period. Cardiac autonomic function (Heart Rate (HR) and Heart Rate Variability (HRV)) and plasma epinephrine (E) and norepinephrine(NE) were taken at four different time points; Ingestion period: baseline (I1), post-ingestion period (I2); Recovery period: immediately post-exercise (R1), post-recovery period (R2). Heart rate variability was assessed in 5-min increments. Results: A repeated measures ANOVA revealed significant time-dependent increases in HR, sympathetic relatedmarkers of HRV, and plasma E and NE at I2 only in the CA + C trial (p\u3c 0.05); however, no meaningful changes in parasympathetic markers of HRV were observed. Participants recovered in a similar time-dependent manner in all markers of HRV and catecholamines following the PLA and CA + C trials. Conclusion: The consumption of CA + C results in an increase of sympathetic activity during resting conditions without influencing parasympathetic activity. CA + C provides no influence over cardiac autonomic recovery

A Comparison of Anaerobic Power Tests using Cycle Ergometry and Non-motorized Treadmill Ergometry at Optimized Loads

International Journal of Exercise Science 16(4): 1293-1305, 2023. The purpose of this study was to compare performance markers derived from a 30-second maximal bout on a cycle ergometer (CE) and non-motorized treadmill (NMT) under optimized loads. Recreationally active participants (n = 40) volunteered for the study. Force-velocity tests on the CE and NMT were used to determine optimal resistance for peak power (PP) production. The remaining visits were randomized and counterbalanced, with a single 30-second maximal test on CE or NMT to assess PP, mean power (MP), fatigue index (FI), over the course of the 30-second test, and maximum heart rate (HRmax) and blood lactate (BLa-) taken 1-minute post. Results were that PP and MP were higher (P\u3c0.05) on CE compared to NMT for both sexes. FI did not differ among males (P=0.201) whereas females showed higher FI (P=0.002) on the CE. HRmax and BLa- were higher (P\u3c0.05) after NMT for both sexes. There was no difference for optimal braking force on NMT between males (16.65±4.49%BW) and females (14.30±3.10%BW) (P=0.061). CE optimal torque factor was higher for males (0.78±0.16 Nm/kg) compared to females (0.62±0.14 Nm/kg) (P=0.001). Overall, CE produced higher power output using optimized loads in recreationally active males and females, while NMT test resulted in a higher HRmax andBLa- concentration. These tests for anaerobic power, when performed with optimized loads, produced different results for several variables, therefore these modalities should not be considered interchangeable. Practitioners should consider which modality best mimics the activities of the person being tested when selecting a protocol

Carbohydrate Rinse Fails to Enhance Cycling Performance or Alter Metabolic and Autonomic Recovery in Recreational Cyclists

The purpose of the study was to examine the effects of carbohydrate (CHO) mouth rinsing on autonomic and metabolic recovery as well as cycling performance. Ten male recreational cyclists (age = 30 ± 6 years, VO2peak = 54.5 ± 8.1 mL·kg-1·min-1) completed a randomized, double-blind, placebo-controlled, crossover designed study. A CHO or a placebo (PLA) rinse was administered every 12.5% of a work to completion trial (75%Wmax). Heart rate variability (lnRMSSD), the respiratory exchange ratio, and plasma epinephrine, norepinephrine, insulin, glucose, free fatty acids (FFA), and lactate were measured pre- and post-exercise. The CHO rinse did not improve time to completion of the test trial (CHO: 4108 ± 307 s, PLA: 4176 ± 374 s, p = 0.545). Further, the CHO rinse did not impact autonomic recovery, as measured by lnRMSSD (p = 0.787) and epinephrine (p = 0.132). Metabolic biomarkers were also unaffected by the CHO rinse, with no differences observed in responses of FFA (p = 0.064), lactate (p = 0.302), glucose (p = 0.113) or insulin (p = 0.408). Therefore, the CHO mouth rinse does not reduce the acute sympathetic response following strenuous exercise and does not result in improvements in cycling time to completion

The influence of sex-division, experience, and pacing strategy on performance in the 2020 CrossFit® Open

To observe workout pacing strategies and determine which best predicted performance, this retrospective study analyzed recorded efforts from a random selection of 160 high-ranking (top 10,000) men and women (n = 80 each) in the 2020 CrossFit® Open (CFO). Video recordings submitted to the official competition leaderboard for all five tests were analyzed to quantify overall test completion rates (and tie-break time for test 5 only) and within-test repetition completion rate (repetitions × sec−1) for each exercise, as well as the quantity of failed repetitions, break strategy (count and duration), and transition times. Each variable was aggregated into first-half, last-half, and total-test averages, slopes, and coefficient of variation; except on test 5 (total-test only). Spearman's rank correlation coefficients were calculated between test completion rates, each test's respective pacing variables, competitor demographics (height and body mass) and CFO experience (i.e., past participation, consecutive competitions, and ranks). Stepwise regression using significantly (p < 0.05) correlated variables produced two prediction models for test performance (best predictor only and best overall model within 8 variables) in a validation group (50% of valid efforts) and then cross-validated against remaining athletes. When no between-group differences were seen, data were combined and used to create the final prediction models for test 1 (r2adj = 0.64–0.96, SEE = 0.4–1.2 repetitions × sec−1), test 2 (r2adj = 0.28–0.85, SEE = 2.0–4.5 repetitions × sec−1), test 3 (r2adj = 0.49–0.81, SEE = 1.1–1.7 repetitions × sec−1), test 4 (r2adj = 0.63–0.78, SEE = 0.6–0.9 repetitions × sec−1), and test 5 (rate: r2adj = 0.71–0.84, SEE = 1.2–1.6 repetitions × sec−1; tie-break time: r2adj = 0.06–0.62, SEE = 1.4–2.3 min). Across the five 2020 CFO tests, the data suggested that repetition pace, breaking strategy, and/or consistency in completing calisthenic-gymnastics components (when prescribed) was most predictive of performance. However, their influence was affected by the complexity of prescribed resistance training exercises and their relative loads. Athletes should prioritize calisthenic-gymnastics components but divert attention to more complex resistance training exercises when prescribed at higher relative intensity loads. Neither previous competition experience nor sex-division altered the hierarchal importance of these considerations

Effects of Heat Exposure on Body Water Assessed using Single-Frequency Bioelectrical Impedance Analysis and Bioimpedance Spectroscopy

International Journal of Exercise Science 10(7): 1085-1093, 2017. The purpose of this study was to determine if heat exposure alters the measures of total body water (TBW), extracellular water (ECW), and intracellular water (ICW) in both single-frequency bioelectrical impedance analysis (BIA) and bioimpedance spectroscopy (BIS). Additionally, we sought to determine if any differences exist between the BIA and BIS techniques before and after brief exposure to heat. Body water was evaluated for twenty men (age=24±4 years) in a thermoneutral environment (22°C) before (PRE) and immediately after (POST) 15 min of passive heating (35°C) in an environmental chamber. The mean difference and 95% limits of agreement at PRE demonstrated that BIS yielded significantly higher body water values than BIA (all p0.05; 0.2±1.5kg). Additionally, the ES of the mean differences at POST were trivial to small and the r-values were high (r≥0.96). When analyzing the changes in body water before and after heat exposure, POST values for BIS were significantly higher than PRE (all

Acute inflammatory responses to high-intensity functional training programming: An observational study

Effects of varying types of short duration workouts in high-intensity functional training (HIFT) on inflammatory biomarkers have not been adequately characterized. Objectives: The purpose of this descriptive study was to examine the acute effects of HIFT workouts on biomarkers of inflammation, over time, in two HIFT bouts. Materials and Methods: Ten apparently healthy males (28.1 ± 5 yrs) completed two HIFT sessions (“short bout:” sub-5-minute vs. “long bout:” 15-minute) in a randomized crossover design. Blood was drawn pre and post-exercise, and 1 hour, 3 hours, and 6 hours post-exercise, centrifuged, and plasma frozen for analysis. Inflammation was assessed through plasma interleukin-6 (IL-6), interleukin-10 (IL-10), and tumour necrosis factor alpha (TNF-α). Results: Repeated measures ANOVA revealed a single trial-dependent difference (IL-6, p≤ 0.05), and while statistically significant, this difference may not be biologically significant. The biomarkers IL-6, IL-10, and TNF-α all follow a similar pattern of peaking post-exercise and returning to baseline within 6 hours in both trials. Conclusions: Both temporal responses and concentrations were similar in the short and long bout. A practical implication is that both bouts of a HIFT elicit certain specific physiologic inflammatory responses

Is caffeine recommended before exercise? A systematic review to investigate its impact on cardiac autonomic control via heart rate and its variability

Evaluating different doses of caffeine (CAF) on heart rate (HR) variability (HRV) during and following exercise in order to assess its impact on autonomic control. We intended to evaluate the influence of CAF as a supplement before exercise on HRV through a systematic review. Manuscripts were selected based on electronic searches of MEDLINE, EMBASE and CINAHL databases from 2010 to 2019 and followed the protocol Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA). Blind randomized designs and controlled trials that reported the influence of CAF on HRV during exercise and during recovery from exercise, with strength of evidence assessed using the GRADE system; the search for the studies was organized using the PICOS strategy. A total of 1797 articles were recognized, following the screening and eligibility stages, 9 studies continued to the final sample. Six studies reported that the combination of CAF supplementation with physical exercise exhibited higher HR when compared to the placebo group during post-exercise recovery; additionally, prolonged activation of sympathetic cardiac control and delayed parasympathetic reactivation following exercise was observed. However, three studies demonstrated no CAF influence when using similar doses. This review observed equivocal results in HR and HRV recovery following exercise with the presence of CAF consumption. These findings cannot confirm the cardiac autonomic changes observed where entirely due to the influence of CAF, and further studies should be performed to better understand this relationship