Rhodiola rosea supplementation on sports performance: A systematic review of randomized controlled trials.

The aim of this systematic review was to determine whether the supplementation with Rhodiola rosea (RR), an herb that has been used for centuries for its various properties, can have an effect on muscle damage and physical performance. The databases PubMed, Web of Science, and Cochrane Library were used to find studies published until March 2023. Randomized controlled trials, healthy participants, and no use of other supplements. The search strategy was conducted by two independent reviewers, and specific information was extracted from the selected studies. Thirteen studies were included with 263 participants (198 men and 65 women between 18 and 65 years old). Two studies followed acute supplementation, 5 chronic, and 6 combined both. The results were heterogenous, having 11 studies with some positive effects, while 2 studies show no effect in variables such as rating of perceive exertion, heart rate, antioxidant capacity, blood lactate, creatine kinase, or C-reactive protein. Two limitations were found, firstly, the difference between supplementation and exercise protocols, and secondly, the existence of unclear or high risk of bias in most of the studies included. Acute supplementation with RR has a positive effect on endurance performance and rating of perceived exertion (RPE). Chronic supplementation has a positive effect on anaerobic exercise performance, but not endurance exercise performance. Chronic supplementation may positively impact muscle damage during exercise. However, more high-quality studies are needed to firmly establish the clinical efficacy of RR.

The effects of an acute dose of Rhodiola rosea on endurance exercise performance.

The purpose of this study was to determine the effects of an acute oral dose of 3 mg·kg(-1) of Rhodiola rosea on endurance exercise performance, perceived exertion, mood, and cognitive function. Subjects (n = 18) ingested either R. rosea or a carbohydrate placebo 1 hour before testing in a double-blind, random crossover manner. Exercise testing consisted of a standardized 10-minute warm-up followed by a 6-mile time trial (TT) on a bicycle ergometer. Rating of perceived exertion (RPE) was measured every 5 minutes during the TT using a 10-point Borg scale. Blood lactate concentration, salivary cortisol, and salivary alpha amylase were measured before warm-up, 2 minutes after warm-up, and 2 minutes after TT (n = 15). A Profile of Mood States questionnaire and a Stroop Color Test were completed before warm-up and after TT. Testing was repeated 2-7 days later with the other condition. Rhodiola rosea ingestion significantly decreased heart rate during the standardized warm-up (R. rosea = 136 ± 17 b·min(-1); placebo = 140 ± 17 b·min(-1); mean ± SD; p = 0.001). Subjects completed the TT significantly faster after R. rosea ingestion (R. rosea = 25.4 ± 2.7 minutes; placebo = 25.8 ± 3.0 minutes; p = 0.037). The mean RPE was lower in the R. rosea trial (R. rosea = 6.0 ± 0.9; placebo = 6.6 ± 1.0; p = 0.04). This difference was even more pronounced when a ratio of the RPE relative to the workload was calculated (R. rosea = 0.048 ± 0.01; placebo = 0.057 ± 0.02; p = 0.007). No other statistically significant differences were observed. Acute R. rosea ingestion decreases heart rate response to submaximal exercise and appears to improve endurance exercise performance by decreasing the perception of effort.

Motivational versus metabolic effects of carbohydrates on self-control.

Self-control is critical for achievement and well-being. However, people's capacity for self-control is limited and becomes depleted through use. One prominent explanation for this depletion posits that self-control consumes energy through carbohydrate metabolization, which further suggests that ingesting carbohydrates improves self-control. Some evidence has supported this energy model, but because of its broad implications for efforts to improve self-control, we reevaluated the role of carbohydrates in self-control processes. In four experiments, we found that (a) exerting self-control did not increase carbohydrate metabolization, as assessed with highly precise measurements of blood glucose levels under carefully standardized conditions; (b) rinsing one's mouth with, but not ingesting, carbohydrate solutions immediately bolstered self-control; and (c) carbohydrate rinsing did not increase blood glucose. These findings challenge metabolic explanations for the role of carbohydrates in self-control depletion; we therefore propose an alternative motivational model for these and other previously observed effects of carbohydrates on self-control.

The reliability of a simulated uphill time trial using the Velotron electronic bicycle ergometer.

This study was conducted to measure the reliability of an indoor uphill time trial (TT) using the Velotron electronic bicycle ergometer with a computer-generated pacer that represented a subject's prior TT performance. A total of 12 trained cyclists (42 ± 7.79 years, 63.0 ± 6.12 ml/kg/min) completed three 8-mile uphill TT with 2-7 days between subsequent tests. A repeated measure ANOVA found no difference between finishing times for TT1 (2,154 ± 246 s) and TT2 (2,078 ± 185 s, p = 0.055) or TT2 and TT3 (2,047 ± 167 s, p = 0.075). All measures of reliability showed an increased reliability for finishing times in TT2-TT3 [95% CI for: coefficient of variation (CV) = 1.0-2.3%, intraclass correlation coefficient (ICC) = 0.953-0.996, standard error of measurement (SEM) = 2.1-4.9 s] versus TT1-TT2 (95% CI for: CV = 2.0-4.9%, ICC = 0.827-0.986, SEM = 9.8-23 s). An uphill TT using the Velotron bicycle ergometer with a prior performance as a pacer is a reliable assessment for indoor TT performance testing, but a familiarization trial improves reliability. Although there were no significant differences found for completion times between TT1-TT2 or TT2-TT3, the absolute mean differences, small sample size and low p values may be suggestive of a Type II error.

Reliability of air displacement plethysmography in a large, heterogeneous sample.

INTRODUCTION: Several studies have assessed the validity of air displacement plethysmography (ADP), but few have assessed the reliability of ADP using a large, heterogeneous sample. PURPOSE: This study was conducted to determine the reliability of ADP using the Bod Pod in a large, heterogeneous sample. METHODS: A total of 980 healthy men and women (30 +/- 15 yr, mean +/- SD) completed two body composition assessments separated by 15-30 min. All testing was done in accordance with the manufacturer's instructions. RESULTS: A significant correlation (r = 0.992, P = 0.001) was found between body density (BD) 1 (1.046 +/- 0.001 kg.L(-1); mean +/- SEM) and BD 2 (1.046 +/- 0.001 kg.L(-1). A paired t-test revealed no significant difference between BD 1 and 2 (P = 0.935). The coefficient of variation (CV) for BD was 0.15%. A significant intraclass correlation coefficient (ICC) was found for BD (ICC = 0.996, P = 0.001), and the standard error of measurement (SEM) was 0.001 kg.L(-1). Body mass (BM) 1 and 2 were correlated significantly (r = 0.999, P = 0.001); however, a significant (P = 0.001) decrease was seen from BM 1 (75.510 +/- 0.461 kg) to BM 2 (75.497 +/- 0.461 kg). Body volume (BV) tended to decrease (P = 0.08) from BV 1 (69.900 +/- 0.449 L) to BV 2 (69.884 +/- 0.449 L). CONCLUSION: ADP using the Bod Pod appears to assess BD reliably; however, the observed CV suggests that multiple trials are necessary to detect small treatment effects.

Postexercise muscle glycogen recovery enhanced with a carbohydrate-protein supplement.

PURPOSE: This study assessed whether liquid carbohydrate-protein (C+P) supplements, ingested early during recovery, enhance muscle glycogen resynthesis versus isoenergetic liquid carbohydrate (CHO) supplements, given early or an isoenergetic solid meal given later during recovery (PLB). METHODS: Two hours after breakfast (7.0 kcal.kg; 0.3 g.kg P, 1.2 g.kg C, 0.1 g.kg F), six male cyclists performed a 60-min time trial (AMex). Pre- and postexercise, vastus lateralis glycogen concentrations were determined using nMRS. Immediately, 1 h, and 2 h postexercise, participants ingested C+P (4.8 kcal.kg; 0.8 g.kg C, 0.4 g.kg P), CHO (4.8 kcal.kg; 1.2 g.kg C), or PLB (no energy). Four hours postexercise, a solid meal was ingested. At that time, C+P and CHO received a meal identical to breakfast, whereas PLB received 21 kcal.kg (1 g.kg P, 3.6 g.kg C, 0.3 g.kg F); energy intake during 6 h of recovery was identical among treatments. After 6 h of recovery, measurement and cycling protocols (PMex) were repeated. RESULTS: Absolute muscle glycogen utilization was 18% greater (P

The effects of supplemental fish oil on blood pressure and morning cortisol in normotensive adults: a pilot study.

PURPOSE: To determine the effects of 6wk of supplementation with fish oil (FO) on blood pressure and the morning salivary cortisol concentration in normotensive adults. METHODS: Testing was performed following an overnight fast. Subjects (n=40; 35+/-13y, mean+/-SD) rested supine for 40min, at which time blood pressure and heart rate were measured. Saliva was collected and analyzed for cortisol. Subjects were then randomly assigned to either: 4g/d of Safflower Oil (SO); or 4g/d of FO supplying 1,600mg/d eicosapentaenoic acid and 800mg/d docosahexaenoic acid. Testing was repeated following 6wk of treatment. RESULTS: Compared to SO, there was a significant decrease in systolic blood pressure with FO (SO=1.3+/-5.8 mmHg; FO=-6.8+/-10.2 mmHg; p=0.004), a significant reduction in pulse pressure (SO=0.2+/-7.8 mmHg; FO=-6.4+/-8.8 mmHg; p=0.02), and a tendency for a decrease in mean arterial pressure (SO=1.2+/-5.3 mmHg; FO=-2.5+/-7.3 mmHg; p=0.08). There was a tendency for salivary cortisol to decrease with FO (SO=0.005+/-0.129 µg/dL; FO=-0.068+/-0.148 µg/dL; p=0.072), however, this change was not significantly correlated with the change in systolic blood pressure (r=0.021, p=0.929). CONCLUSION: 6wk of supplementation with FO significantly decreases systolic blood pressure in normotensive adults and this change was not significantly correlated with a reduction in salivary cortisol.

Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults.

BACKGROUND: To determine the effects of supplemental fish oil (FO) on resting metabolic rate (RMR), body composition, and cortisol production in healthy adults. METHODS: A total of 44 men and women (34 ± 13y, mean+SD) participated in the study. All testing was performed first thing in the morning following an overnight fast. Baseline measurements of RMR were measured using indirect calorimetry using a facemask, and body composition was measured using air displacement plethysmography. Saliva was collected via passive drool and analyzed for cortisol concentration using ELISA. Following baseline testing, subjects were randomly assigned in a double blind manner to one of two groups: 4 g/d of Safflower Oil (SO); or 4 g/d of FO supplying 1,600 mg/d eicosapentaenoic acid (EPA) and 800 mg/d docosahexaenoic acid (DHA). All tests were repeated following 6 wk of treatment. Pre to post differences were analyzed using a treatment X time repeated measures ANOVA, and correlations were analyzed using Pearson's r. RESULTS: Compared to the SO group, there was a significant increase in fat free mass following treatment with FO (FO = +0.5 ± 0.5 kg, SO = -0.1 ± 1.2 kg, p = 0.03), a significant reduction in fat mass (FO = -0.5 ± 1.3 kg, SO = +0.2 ± 1.2 kg, p = 0.04), and a tendency for a decrease in body fat percentage (FO = -0.4 ± 1.3% body fat, SO = +0. 3 ± 1.5% body fat, p = 0.08). No significant differences were observed for body mass (FO = 0.0 ± 0.9 kg, SO = +0.2 ± 0.8 kg), RMR (FO = +17 ± 260 kcal, SO = -62 ± 184 kcal) or respiratory exchange ratio (FO = -0.02 ± 0.09, SO = +0.02 ± 0.05). There was a tendency for salivary cortisol to decrease in the FO group (FO = -0.064 ± 0.142 µg/dL, SO = +0.016 ± 0.272 µg/dL, p = 0.11). There was a significant correlation in the FO group between change in cortisol and change in fat free mass (r = -0.504, p = 0.02) and fat mass (r = 0.661, p = 0.001). CONCLUSION: 6 wk of supplementation with FO significantly increased lean mass and decreased fat mass. These changes were significantly correlated with a reduction in salivary cortisol following FO treatment.

Recovery from a cycling time trial is enhanced with carbohydrate-protein supplementation vs. isoenergetic carbohydrate supplementation.

BACKGROUND: In this study we assessed whether a liquid carbohydrate-protein (C+P) supplement (0.8 g/kg C; 0.4 g/kg P) ingested early during recovery from a cycling time trial could enhance a subsequent 60 min effort on the same day vs. an isoenergetic liquid carbohydrate (CHO) supplement (1.2 g/kg). METHODS: Two hours after a standardized breakfast, 15 trained male cyclists completed a time trial in which they cycled as far as they could in 60 min (AM(ex)) using a Computrainer indoor trainer. Following AM(ex), subjects ingested either C+P, or CHO at 10, 60 and 120 min, followed by a standardized meal at 4 h post exercise. At 6 h post AM(ex) subjects repeated the time trial (PM(ex)). RESULTS: There was a significant reduction in performance for both groups in PM(ex) versus AM(ex). However, performance and power decreases between PM(ex) and AM(ex) were significantly greater (p

The role of protein and amino acid supplements in the athlete's diet: does type or timing of ingestion matter?

Rather than the age-old debate regarding overall protein and amino acid needs of athletes, this paper focuses on the importance of timing and type of protein and amino acid ingestion relative to both muscle growth and exercise performance. Evidence discussed comes from definitive measurement techniques including net protein balance determinations (for acute studies) or quantification of muscle size or strength (for chronic studies) First, recent data indicate that consuming a small meal of mixed macronutrient composition (or perhaps even a very small quantity of a few indispensable amino acids) immediately before or following strength exercise bouts can alter significantly net protein balance, resulting in greater gains in both muscle mass and strength than observed with training alone. With aerobic exercise, some evidence suggests immediate postexercise (but perhaps not pre-exercise) supplementation is also beneficial. Second, protein type may also be important owing to variable speeds of absorption and availability, differences in amino acid and peptide profiles, unique hormonal response, or positive effects on antioxidant defense. In addition to athletes, many others who desire to regain, maintain, or enhance muscle mass or function, including those with muscle-wasting diseases, astronauts, and all of us as we age, need to ensure that nutrient availability is sufficient during the apparently critical anabolic window of time associated with exercise training sessions. Future studies are needed to fine tune these recommendations.