Athanasios Gatsas

Purpose : To determine the recovery kinetics of performance, muscle damage, and neuromuscular fatigue following 2 speed-endurance maintenance training (SEMT) protocols in soccer. Methods : Ten well-trained male soccer athletes randomly completed 3 trials: work-to-rest ratio SEMT/1:3, SEMT/1:1, and a control trial. Training load during SEMT was monitored using a global positioning system and heart-rate monitors. Isokinetic strength of knee extensors and flexors; repeated-sprint ability (RSA); speed 10-, 30-m, countermovement jump (CMJ); and muscle damage (delayed-onset muscle soreness [DOMS] and creatine kinase) markers were evaluated at baseline and at 0, 24, 48, and 72 hours posttraining. Maximal voluntary contraction of knee extensors and flexors was additionally assessed at 1, 2, and 3 hours posttraining. Results : Strength (eccentric torque) and speed performance (RSA, 10-m and 30-m sprint times) were reduced ( P < .05) following the SEMT/1:3 for up to 72 and 48 hours, respectively, and following SEMT/1:1 for up to 48 and ≤24 hours, respectively. Eccentric torque and RSA deterioration was greater in SEMT/1:3 compared to SEMT/1:1 at 72 hours and immediately postexercise, respectively ( P < .05). Indicators of neuromuscular fatigue (CMJ and maximal voluntary contraction) declined in SEMT/1:3 at 24 and 2 hours postexercise ( P < .05) and in SEMT/1:1 immediately and at 2 hours postexercise ( P < .05). Muscle damage (DOMS) in the knee flexors was elevated in both SEMT protocols for up to 48 hours ( P < .05). Conclusions : SEMT/1:3 induces short-term neuromuscular fatigue; provokes a decrease of strength (48–72 h), speed and RSA (48 h), and jump height (24 h); and is related with an elevation of knee flexors’ DOMS (48 h). Increased work-to-rest ratio causes higher levels of exercise-induced muscle damage.

Type 2 diabetes (T2D) is the predominant metabolic epidemic posing a major threat to global health. Growing evidence indicates that gut microbiota (GM) may critically influence the progression from normal glucose tolerance, to pre-diabetes, to T2D. On the other hand, regular exercise contributes to the prevention and/or treatment of the disease, and evidence suggests that a possible way regular exercise favorably affects T2D is by altering GM composition toward health-promoting bacteria. However, research regarding this potential effect of exercise-induced changes of GM on T2D and the associated mechanisms through which these effects are accomplished is limited. This review presents current data regarding the association of GM composition and T2D and the possible critical GM differentiation in the progression from normal glucose, to pre-diabetes, to T2D. Additionally, potential mechanisms through which GM may affect T2D are presented. The effect of exercise on GM composition and function on T2D progression is also discussed.

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.

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).

This study investigated whether Greek Orthodox Christian fasting during Holy Week can change body composition and cardiometabolic parameters in overweight individuals, and whether these changes are maintained one week after fasting cessation (FC). Body composition and physiological and biochemical parameters were measured before, immediately after (n = 23) and one week after FC (subgroup of n = 10). Fasting resulted in decreased body weight, waist circumference, waist-to-hip ratio, body mass index and total body fat, as well as blood glucose, total cholesterol and low-density lipoprotein cholesterol levels. Nutrition analysis showed a decreased protein and saturated fat intake during fasting. FC (n = 10) resulted in a decreased carbohydrate intake and increased protein and cholesterol intake compared to fasting. Fasting resulted in decreased blood glucose, total cholesterol and LDL cholesterol levels but returned to pre-fasting levels after FC. Greek Orthodox Christian fasting during Holy Week is beneficial for body composition and some aspects of cardiometabolic health. However, these favourable changes are not maintained one week following fasting.