Using blood lactate concentration to predict muscle damage and jump performance response to maximal stretch-shortening cycle exercise

Low-Volume Squat Jump Training Improves Functional Performance Independent of Myofibre Changes in Inactive Young Male Individuals

An investigation into the histological changes in skeletal muscle fibres and jump performance indicators after 8 weeks of plyometric squat jump training was conducted. Healthy inactive participants (n = 13; age: 21.5 ± 1.7 year.; height: 173.6 ± 10.7 cm; weight: 68.5 ± 18.4 kg; BMI 22.4 ± 3.8 kg/m²) were recruited, where eight participants completed plyometric squat jump training and five control participants refrained from performing any jumping activities. Blood samples, vastus lateralis muscle biopsies and functional testing (peak and average power, peak and average velocity, maximal jump height) were collected/recorded 10 days prior to and 3 days after the training/rest period. Participants completed 1644 squat jumps over an 8-week training period of 24 sessions with a progressive increase in the number of squat jumps. The trained group significantly increased their jumping average and peak power (mean increases in average power: 16.7 ± 1.2% and peak power: 8.2% ± 0.1) and velocity (mean increases in average velocity: 13.7 ± 0.1% and peak velocity: 5.2% ± 0.03), resulting in a 25% improvement in vertical jump height. No muscle morphological changes in terms of the cross-sectional area (CSA) or muscle-fibre-type transition were observed after the plyometric training. Improvements in the functional performance indicators following training may more likely be explained by sarcomere ultrastructural adaptation, which did not directly affect myosin heavy chain or CSA.

Blood Lactate Decreased by Foam Rolling Post-Quarter Marathon

BACKGROUND: New training methods, increased volume, the prolonged duration could induce the delayed onset of muscle soreness (DOMS), and it is associated with blood lactate (BL). Foam roller (FR) is known as a tool for active recovery. AIM: The study’s purposes are to assess the effect of the Quarter Marathon (QM) and Foam Roller (FR) on blood lactate (BL). METHODS: This is a pilot study with a quasi-repeated-measures design. Ten trained young males were voluntarily signed up using the purposive sampling technique. The Accutrend-Plus by Roche was used to measure BL. Blood lactate was measured 6 times. Combination FR protocols from the Master of Muscle and Casall were used. Repeated-measures ANOVA test was used to analyze the changes in BL. RESULTS: Blood lactate significantly increased 4.90 ± 3.0 (mmol/L) post-QM as p < 0.05, pre-test 2.23 ± 0.8 (mmol/L) compared to post-running 7.1 ± 2.6 (mmol/L). It was decreased after foam rolling activity 4.33 ± 0.7 (mmol/L), and 3.06 ± 0.5 (mmol/L) at 120 min post-running, then returned to normal after 24 h post-QM 2.44 ± 0.5 (mmol/L). CONCLUSION: Foam rolling potentially decreased BL after QM.

Metabolomic and proteomic characterization of sng and pain phenotypes in fibromyalgia

BACKGROUND

Fibromyalgia (FM) is characterized by chronic widespread pain. Its pathophysiological mechanisms remain poorly understood, and effective diagnosis and treatments are lacking. This study aimed to identify significantly changed biosignatures in FM and propose a novel classification for FM based on pain and soreness (sng) symptoms.

METHODS

Urine and serum samples from 30 FM patients and 25 controls underwent metabolomic and proteomic profiling.

RESULTS

Compared with controls, FM patients showed significant differential expression of three metabolites in urine and five metabolites and eight proteins in serum. Of them, DETP, 4-guanidinobutanoic acid, SM(d18:1/18:0), PC(20:1(11Z)/18:0), S100A7, SERPINB3, galectin-7 and LYVE1 were first reported as potential biomarkers for FM. Furthermore, lactate, 2-methylmaleate and cotinine in urine and lactate, SM(d18:1/25:1), SM(d18:1/26:1) and prostaglandin D2 (PGD2) and PCYOX1, ITIH4, PFN1, LRG1, C8G, C8A, CP, CDH5 and DBH in serum could differentiate pain- (PG) and sng-dominant groups (SG). Lactate, 2-methylmaleate, cotinine, PCYOX1, ITIH4, PFN1 and DBH have a higher level in SG. SM(d18:1/25:1), SM(d18:1/26:1), PGD2, LRG1, C8G, C8A, CP and CDH5 in SG are lower than PG. The omics results indicated disordered free radical scavenging, and lipid and amino acid metabolism networks and resulting NF-κB-dependent cytokine generation in FM. Lactate level was altered simultaneously in urine and serum and significantly higher in sng-dominant patients than others.

CONCLUSIONS

In this study, we identified potential biomarkers from FM patients. The selected biomarkers could discriminate sng and pain phenotypes in FM patients. These results could help elucidate the underlying pathological mechanisms for more effective diagnosis and therapy for FM.

The Dose Response of Taurine on Aerobic and Strength Exercises: A Systematic Review

Taurine is a naturally occurring amino acid involved in various functions, including regulating ion channels, cell volume, and membrane stabilization. However, how this molecule orchestrates such functions is unknown, particularly the dose response in exercised muscles. Therefore, this review aimed to systematically review the dose response of taurine on both aerobic and strength exercise performance. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, relevant articles were sought on PubMed, Medline, Web of Science, and Google Scholar using related terms, including taurine, exercise performance, exercise, muscle, physical training, running, strength, endurance exercise, resistance exercise, aerobic exercise, and swimming. Ten articles were retrieved, reviewed, and subjected to systematic analysis. The following parameters were used to assess exercise performance in the selected studies: creatine kinase (CK), lactic acid dehydrogenase, carbohydrate, fat, glycerol, malondialdehyde, enzymatic antioxidants, blood pH, taurine level, and muscular strength. From the selected literature, we observed that taurine supplementation (2 g three times daily) with exercise can decrease DNA damage. Furthermore, 1 g of acute taurine administration before or after exercise can decrease lactate levels. However, acute administration of taurine (6 g) at a high dose before the start of exercise had no effect on reducing lactate level, but increased glycerol levels, suggesting that taurine could be an effective agent for prolonged activities, particularly at higher intensities. However, further studies are warranted to establish the role of taurine in fat metabolism during exercise. Finally, we observed that a low dose of taurine (0.05 g) before performing strength enhancing exercises can decrease muscular fatigue and increase enzymatic antioxidants.

Systematic Review Registration:http://www.crd.york.ac.uk/PROSPERO, PROSPERO (CRD42021225243).

Relationship between Skin Temperature, Electrical Manifestations of Muscle Fatigue, and Exercise-Induced Delayed Onset Muscle Soreness for Dynamic Contractions: A Preliminary Study

Delayed onset muscle soreness (DOMS) indicates the presence of muscle damage and impairs force production and control. Monitorization of DOMS is useful to improving recovery intervention plans. The magnitude of DOMS may relate to muscle fatigue, which can be monitored by surface electromyography (EMG). Additionally, growing interest has been expressed in determining whether the skin temperature over a muscle group during exercise to fatigue could be a non-invasive marker for DOMS. Here we determine whether skin temperature and manifestations of muscle fatigue during exercise are correlated and can predict DOMS after concentric-eccentric bicep curl exercises. We tested 10 young adults who performed concentric-eccentric bicep curl exercises to induce muscle damage in the biceps brachialis to investigate the relationship between skin temperature and fatigue during exercise and DOMS after exercise. Muscle activation and skin temperature were recorded during exercise. DOMS was evaluated 24 h after exercise. Data analysis was performed using Bayesian regression models with regularizing priors. We found significant muscle fatigue and an increase in skin temperature during exercise. DOMS was observed 24 h after exercise. The regression models showed no correlation of changes in skin temperature and muscle fatigue during exercise with DOMS 24 h after exercise. In conclusion, our preliminary results do not support a relationship between skin temperature measured during exercise and either muscle fatigue during exercise or the ability to predict DOMS 24 h after exercise.

Cold water immersion recovery strategy increases blood pressure levels after high-intensity intermittent exercise

BACKGROUND

This study aimed to investigate the effects of cold water immersion (CWI) recovery strategies on the blood pressure levels and related physiological parameters after high-intensity intermittent exercise (HIIE).

METHODS

This randomized crossover study included 20 men (21.5±1.6 years). Each participant performed a maximum-exertion exercise performance test on a bicycle, and heart rate was measured. Subsequently, six cycles of HIIE (1 minute at 120% heart rate reserve [HRR] and 4 minutes at 40% HRR) were performed in a random sequence, and the recovery period involved either CWI or static rest (SR).

RESULTS

Systolic and diastolic blood pressure levels at the 6th and 20th minute of CWI recovery were significantly higher than those during SR and significantly higher than those during a quiet state at the 6th minute. The heart rates at the 20th minute and 35th minute of CWI recovery were significantly lower than that during SR, and the ratings of perceived exertion (RPE) at the 6th and 20th minute of CWI recovery were significantly lower than that during SR. No significant difference in lactate production was evident between the two recovery strategies. Ear temperature was not significantly different when it was quiet, at the end of exercise, and at the 6th and 35th minute of recovery; however, at the 20th minute of recovery, ear temperature during CWI was significantly higher than that during SR.

CONCLUSIONS

CWI after HIIE reduced the extent to which blood pressure decreased. For the fatigue-related heart rate and RPE indicators, CWI was superior to SR.