Effect of two different long-sprint training regimens on sprint performance and associated metabolic responses

Changes of Anaerobic Power and Lactate Concentration following Intense Glycolytic Efforts in Elite and Sub-Elite 400-meter Sprinters

400-m races are based on anaerobic energy metabolism, they induce significant muscle fatigue, muscle fiber damage, and high blood lactate (LA) concentration. Despite extensive research on sprint training, our understanding of the training process that leads to world-class sprint performance is rather limited. This study aimed to determine differences in LA concentration and anaerobic power using jumping tests after an intense glycolytic effort in a group of elite and sub-elite 400-m runners. One hundred thirty male runners were divided into two groups: elite (n = 66, body mass = 73.4 ± 7.8 kg, body height = 182.1 ± 6.2 cm, age = 20.8 ± 4.0 y) running the 400-m dash below 50 s and sub-elite (n = 64, body mass = 72.0 ± 7.1 kg, body height = 182.1 ± 5.2 cm, age = 20.8 ± 4.0 y) with a 400-m personal best above 50 s. The power of the countermovement and the sequential squat jumps was measured in two sets after a warm-up, followed by two intermittent 30-s Wingate tests. LA concentration was measured eight times. It was observed that elite athletes achieved significantly higher power in both types of jumps. The maximum post-exercise LA concentration was significantly lower in the sub-elite group after the 3rd, the 6th, the 9th, and the 20th min after the cessation of two Wingate tests (p < 0.001). The rate of LA accumulation after exercise and the rate of LA utilization did not differ between the groups. It can be concluded that elite and non-elite runners differ in higher LA production but not in LA utilization. Anaerobic power and LA concentration seem to differentiate between 400 elite and sub-elite performance.

The effect of pre-exercise alkalosis on lactate/pH regulation and mitochondrial respiration following sprint-interval exercise in humans

Purpose: The purpose of this study was to evaluate the effect of pre-exercise alkalosis, induced via ingestion of sodium bicarbonate, on changes to lactate/pH regulatory proteins and mitochondrial function induced by a sprint-interval exercise session in humans. Methods: On two occasions separated by 1 week, eight active men performed a 3 × 30-s all-out cycling test, interspersed with 20 min of recovery, following either placebo (PLA) or sodium bicarbonate (BIC) ingestion. Results: Blood bicarbonate and pH were elevated at all time points after ingestion in BIC vs PLA (p < 0.05). The protein content of monocarboxylate transporter 1 (MCT1) and basigin (CD147), at 6 h and 24 h post-exercise, and sodium/hydrogen exchanger 1 (NHE1) 24 h post-exercise, were significantly greater in BIC compared to PLA (p < 0.05), whereas monocarboxylate transporter 4 (MCT4), sodium/bicarbonate cotransporter (NBC), and carbonic anhydrase isoform II (CAII) content was unchanged. These increases in protein content in BIC vs. PLA after acute sprint-interval exercise may be associated with altered physiological responses to exercise, such as the higher blood pH and bicarbonate concentration values, and lower exercise-induced oxidative stress observed during recovery (p < 0.05). Additionally, mitochondrial respiration decreased after 24 h of recovery in the BIC condition only, with no changes in oxidative protein content in either condition. Conclusion: These data demonstrate that metabolic alkalosis induces post-exercise increases in several lactate/pH regulatory proteins, and reveal an unexpected role for acidosis in mitigating the loss of mitochondrial respiration caused by exercise in the short term.

Anaerobic Speed Reserve, Sprint Force-Velocity Profile, Kinematic Characteristics, and Jump Ability among Elite Male Speed- and Endurance-Adapted Milers

This study aimed to compare sprint, jump performance, and sprint mechanical variables between endurance-adapted milers (EAM, specialized in 1500–3000-m) and speed-adapted milers (SAM, specialized in 800–1500 m) and to examine the relationships between maximal sprint speed (MSS), anaerobic speed reserve (ASR), sprint, jump performance, and sprint mechanical characteristics of elite middle-distance runners. Fifteen participants (8 EAM; 7 SAM) were evaluated to obtain their maximal aerobic speed, sprint mechanical characteristics (force–velocity profile and kinematic variables), jump, and sprint performance. SAM displayed greater MSS, ASR, horizontal jump, sprint performance, and mechanical ability than EAM (p < 0.05). SAM also showed higher stiffness in the 40-m sprint (p = 0.026) and a higher ratio of horizontal-to-resultant force (RF) at 10 m (p = 0.003) and RFpeak (p = 0.024). MSS and ASR correlated with horizontal (r = 0.76) and vertical (r = 0.64) jumps, all sprint split times (r ≤ −0.85), stiffness (r = 0.86), and mechanical characteristics (r ≥ 0.56) during the 100-m sprint, and physical qualities during acceleration (r ≥ 0.66) and sprint mechanical effectiveness from the force–velocity profile (r ≥ 0.69). Season-best times in the 800 m were significantly correlated with MSS (r = −0.86). Sprint ability has a crucial relevance in middle-distance runners’ performance, especially for SAM.

Does the Minerals Content and Osmolarity of the Fluids Taken during Exercise by Female Field Hockey Players Influence on the Indicators of Water-Electrolyte and Acid-Basic Balance?

Although it is recognized that dehydration and acidification of the body may reduce the exercise capacity, it remains unclear whether the qualitative and quantitative shares of certain ions in the drinks used by players during the same exertion may affect the indicators of their water–electrolyte and acid–base balance. This question was the main purpose of the publication. The research was carried out on female field hockey players (n = 14) throughout three specialized training sessions, during which the players received randomly assigned fluids of different osmolarity and minerals contents. The water–electrolyte and acid–base balance of the players was assessed on the basis of biochemical blood and urine indicators immediately before and after each training session. There were statistically significant differences in the values of all examined indicators for changes before and after exercise, while the differences between the consumed drinks with different osmolarities were found for plasma osmolality, and concentrations of sodium and potassium ions and aldosterone. Therefore, it can be assumed that the degree of mineralization of the consumed water did not have a very significant impact on the indicators of water–electrolyte and acid–base balance in blood and urine.

Mechanical and Metabolic Responses during High-intensity Training in Elite 800-m Runners

The purpose of this study was to describe the mechanical and metabolic responses of a typical high-intensity training session in high-level 800-m athletes. Nine male high-level 800-m athletes (personal best 1:43-1:56 min:ss) performed a typical high-intensity interval training session consisting of 5×200 m with 4 min rest. Countermovement jump and blood lactate were measured at rest and after each running bout. Running times, ground contact times, and stride length were also measured. Running times and lactate (p<0.01) progressively increased from the first to the last running bout. Jump height (p<0.01) and stride length (p<0.05) progressively decreased from the first running bout to the last. A significant negative relationship (p<0.001; r =-0.83) was found between the individual values of jumping height and blood lactate concentration; and a significant positive relationship (p<0.01; r=0.67) was observed between the time in the 200 m and the contact times. In conclusion, the results demonstrated that the typical training session performed by 800-m athletes produced a high level of fatigue as evidenced by significant alterations in the mechanical and metabolic response. The impairments observed in the mechanical and metabolic parameters may indirectly reflect a state of energy deficit of the muscle contractile machinery and a reduction of the force-generating capacity.

Effect of Simulated Matches on Post-Exercise Biochemical Parameters in Women's Indoor and Beach Handball

This study assesses the status of hydration and the acid-base balance in female handball players in the Polish Second League before and after simulated matches in both indoor (hall) and beach (outdoor) conditions. The values of biochemical indicators useful for describing water-electrolyte management, such as osmolality, hematocrit, aldosterone, sodium, potassium, calcium, chloride and magnesium, were determined in the players’ fingertip capillary blood. Furthermore, the blood parameters of the acid-base balance were analysed, including pH, standard base excess, lactate and bicarbonate ion concentration. Additionally, the pH and specific gravity of the players’ urine were determined. The level of significance was set at p < 0.05. It was found that both indoor and beach simulated matches caused post-exercise changes in the biochemical profiles of the players’ blood and urine in terms of water-electrolyte and acid-base balance. Interestingly, the location of a simulated match (indoors vs. beach) had a statistically significant effect on only two of the parameters measured post-exercise: concentration of calcium ions (lower indoors) and urine pH (lower on the beach). A single simulated game, regardless of its location, directly affected the acid-base balance and, to a smaller extent, the water-electrolyte balance, depending mostly on the time spent physically active during the match.