Characterization of the Sideritis scardica Extract SidTea+TM and Its Effect on Physiological Profile, Metabolic Health and Redox Biomarkers in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study.

This study aimed to characterize a Sideritis scardica extract (SidTea+TM) and investigate its effect on the physiological profile, metabolic health and redox status in healthy individuals. The chemical profile and antioxidant potential of the SidTea+TM extract were evaluated by UPLC-HRMS analysis and in vitro cell-free methods. Twenty-eight healthy adults participated in this randomized, double-blind, placebo-controlled study. Participants consumed 1500 mg/day of SidTea+TM or a placebo for 4 weeks. At baseline and post-supplementation, participants were assessed for their anthropometric and physiological profile and provided a resting blood sample. SidTea+TM decreased (p < 0.05) systolic blood pressure (-10.8 mmHg), mean arterial pressure (-4.5 mmHg), resting heart rate (-3.1 bpm) and handgrip strength of the non-dominant limb (-0.8 kg) whereas the placebo decreased (p < 0.05) handgrip strength of the dominant (-5.8 kg) and non-dominant (-3.2 kg) limb. SidTea+TM also resulted in an increase (p < 0.05) in estimated VO2max (+1.1 mL/kg/min) and a reduction (p < 0.05) in γ-GT and SGPT enzymatic activity in serum (-3.7 and -3.3 U/L, respectively). Finally, SidTea+TM increased (p < 0.001) total antioxidant capacity and decreased (p < 0.05) lipid peroxidation levels in plasma. These results indicate that SidTea+TM is a potent and safe to use antioxidant that can elicit positive changes in indices of blood pressure, cardiorespiratory capacity, liver metabolism, and redox status in healthy adults over a 4-week supplementation period.

Recovery During Successive 120-min Football Games: Results from the 120-min Placebo/Carbohydrate Randomized Controlled Trial.

PURPOSE: To examine the recovery kinetics (i.e. time-dependent changes) of performance-related variables between two 120-min male football games performed three days apart with and without carbohydrate (CHO) supplementation. METHODS: 20 male players (20 ± 1 years; body fat: 14.9 ± 5.1%; VO2max: 59.4 ± 3.7 mL•kg-1•min-1) participated in two 120-min football games (G1, G2) according to a randomized, two-trial, repeated measures, cross-over, double-blind design. Participants received carbohydrate/Placebo supplements during recovery between games. Field activity was monitored during the games. Performance testing and blood sampling were performed before, at 90- and 120-min of each game. Muscle biopsies were collected at baseline, 90- and 120-min of G1 and pre-G2. RESULTS: Compared to G1, G2 was associated with reduced total distance (10,870 vs. 10,685 m during 90-min and 3,327 vs. 3,089 m during extra 30-min; p = 0.007-0.038), average (6.7 vs. 6.2 m•s-1 during extra 30-min match-play; p = 0.007) and maximal speed (32.2 vs. 30.2 m•s-1 during 90-min and 29.0 vs. 27.9 m•s-1 during extra 30-min; p < 0.05), accelerations/decelerations (p < 0.05) and mean HR (p < 0.05). Repeated sprint ability (p < 0.001), jumping (p < 0.05) and strength (p < 0.001) performance were compromised before and during G2. Muscle glycogen was not restored at G2-baseline (p = 0.005). Extended game-play reduced lymphocyte, erythrocyte counts, hematocrit, hemoglobin, reduced glutathione (p < 0.05) and increased DOMS, creatine kinase activity, blood glycerol and ammonia (p < 0.05) and protein carbonyls (p < 0.05) before and during G2. Pax7+ (p = 0.004) and MyoD+ cells (p = 0.019) increased at baseline-G2. Carbohydrate supplementation restored performance and glycogen, reduced glycerol and DOMS responses, and increased leukocyte counts and Pax7+ and MyoD+ cells. CONCLUSIONS: Results suggest that extended football games induce a prolonged recovery of performance which may be facilitated by carbohydrate supplementation during a congested game fixture.

Recovery kinetics following sprint training: resisted versus unresisted sprints.

PURPOSE: To determine the recovery kinetics of performance and exercise-induced muscle damage following different sprint-training protocols. METHODS: In a crossover design, ten male and female athletes (20.6 ± 2.4 years) performed 2 × (3 × 20 m: 2 min rest) and 1× (3 × 30 m: 3 min rest) of: (a) unresisted sprints (UST), (b) resisted sprints with 10% of body mass (BM) load (RST10), (c) resisted sprints with 20% BM load (RST20), against a control trial (no-training). RESULTS: Blood lactate (mmol/L) increased post-training versus pre-training in all sprint-training trials (6.7 ± 2.4 vs 1.2 ± 0.2, 5.6 ± 2.4 vs 1.3 ± 0.3, 7.3 ± 2.7 vs 1.2 ± 0.3, in UST, RST10, RST20, respectively), as did creatine kinase (U/L) 24 h, 48 h and 72 h post-training (UST: 251 ± 173, 238 ± 154, 209 ± 115 vs 155 ± 9, RST10: 252 ± 134, 240 ± 83, 218 ± 103 vs 164 ± 106; RST20: 237 ± 133, 323 ± 303, 262 ± 184 vs 179 ± 106, respectively). DOMS of knee-extensors (KE) and knee-flexors (KF) increased post-training up to 72 h in all sprint-training trials versus pre-training (ranging from 1.6 ± 1.3 to 3.8 ± 2.8 vs 1.0 ± 0, respectively). Eccentric torque (N m) of the KE of the non-dominant limb, decreased 24 h post-training versus pre-training in all sprint-training trials (UST: 249 ± 49 vs 266 ± 54; RST10: 229 ± 52 vs 273 ± 72; RST20: 253 ± 6 vs 262 ± 56), as did that of the KF of the dominant limb (UST: 135 ± 29 vs 144 ± 26; RST10: 130 ± 29 vs 140 ± 25; RST20: 139 ± 33 vs 142 ± 26). 10-m sprint-time (s) increased 48 h post-training versus pre-training (1.81 ± 0.15 vs 1.77 ± 0.11), and 30-m sprint-time increased 24 h, 48 h, 72 h post-training versus pre-training (4.35 ± 0.36, 4.40 ± 0.44, 4.33 ± 0.41 vs 4.21 ± 0.34, respectively), only in RST20. CONCLUSIONS: Unresisted and resisted sprint-training induces prolonged reduction of muscle strength (24 h), and sprinting performance (72 h), associated with prolonged increase of DOMS and CK (72 h).

Recovery kinetics following eccentric exercise is volume-dependent.

The present study compared the effect of 75 vs 150 vs 300 intensity-matched eccentric contractions on muscle damage and performance recovery kinetics. Ten healthy males participated in a randomized, cross-over study consisted of 4 experimental trials (ECC75, ECC150, ECC300 and Control - no exercise) with a 4-week washout period in-between. Performance and muscle damage, inflammatory and oxidative stress markers were evaluated at baseline, post-exercise, 24, 48 and 192 hours following each exercise protocol. Concentric and eccentric peak torque decreased similarly in ECC150 and ECC300 during the first 48 h of recovery (p < 0.05) but remained unaffected in ECC75. Countermovement jump indices decreased post-exercise and at 24 h in ECC150 and ECC300, with ECC300 inducing a more pronounced reduction (p < 0.05). Creatine kinase increased until 48 h of recovery in all trials and remained elevated up to 192 h only in ECC300 (p < 0.05). Delayed onset of muscle soreness increased, and knee-joint range of motion decreased in a volume-dependent manner during the first 48 h (p < 0.05). Likewise, a volume-dependent decline of glutathione and a rise of protein carbonyls was observed during the first 48 h of recovery (p < 0.05). Collectively, our results indicate that muscle damage and performance recovery following eccentric exercise is volume dependent, at least in lower limbs.

Skeletal muscle and erythrocyte redox status is associated with dietary cysteine intake and physical fitness in healthy young physically active men.

PURPOSE: To investigate the association between redox status in erythrocytes and skeletal muscle with dietary nutrient intake and markers of physical fitness and habitual physical activity (PA). METHODS: Forty-five young physically active men were assessed for body composition, dietary nutrient intake, muscle strength, cardiorespiratory capacity and habitual PA. Blood and muscle samples were collected to estimate selected redox biomarkers. Partial correlation analysis was used to evaluate the independent relationship of each factor with redox biomarkers. RESULTS: Dietary cysteine intake was positively correlated (p < 0.001) with both erythrocyte (r = 0.697) and muscle GSH (0.654, p < 0.001), erythrocyte reduced/oxidized glutathione ratio (GSH/GSSG) (r = 0.530, p = 0.001) and glutathione reductase (GR) activity (r = 0.352, p = 0.030) and inversely correlated with erythrocyte protein carbonyls (PC) levels (r = - 0.325; p = 0.046). Knee extensors eccentric peak torque was positively correlated with GR activity (r = 0.355; p = 0.031) while, one-repetition maximum in back squat exercise was positively correlated with erythrocyte GSH/GSSG ratio (r = 0.401; p = 0.014) and inversely correlated with erythrocyte GSSG and PC (r = - 0.441, p = 0.006; r = - 0.413, p = 0.011 respectively). Glutathione peroxidase (GPx) activity was positively correlated with step count (r = 0.520; p < 0.001), light (r = 0.406; p = 0.008), moderate (r = 0.417; p = 0.006), moderate-to-vigorous (r = 0.475; p = 0.001), vigorous (r = 0.352; p = 0.022) and very vigorous (r = 0.326; p = 0.035) PA. Muscle GSSG inversely correlated with light PA (r = - 0.353; p = 0.022). CONCLUSION: These results indicate that dietary cysteine intake may be a critical element for the regulation of glutathione metabolism and redox status in two different tissues pinpointing the independent significance of cysteine for optimal redox regulation. Musculoskeletal fitness and PA levels may be predictors of skeletal muscle, but not erythrocyte, antioxidant capacity. TRIAL REGISTRATION: Registry: ClinicalTrials.gov, identifier: NCT03711838, date of registration: October 19, 2018.