Lower and upper extremity contributions to propulsion and resistance during semi-tethered load-velocity profiling in front crawl swimming.

The study estimated lower and upper extremity contributions to whole-body front crawl swimming using semi-tethered load-velocity profiling. Nine female and 11 male (inter)national-level swimmers performed 20 m semi-tethered sprints, each with five progressive loads for lower (leg kicking), upper (arm stroke), and whole-body front crawl movements. The theoretical maximal speed (v0) and load (L0), and active drag (Da) were expressed as a percentage of the sum of both extremities for the movements of each extremity to calculate their contributions. The difference of whole-body values minus the sum of both extremities was used to estimate whole-body reserves. Lower (upper) body contributions were 43.8 ± 2.8% (56.2%) for v0, 37.3 ± 7.1% (62.7%) for L0, and 39.6 ± 5.6% (60.4%) for Da. Statistically significant whole-body reserves were found for v0 (-30.9 ± 3.9%, p < 0.001) and Da (-5.7 ± 11.7%, p = 0.04). V0 reserves correlated very highly with whole-body v0 in males (r = 0.71, p = 0.014) and moderately in females (r = 0.47, p = 0.21). The lower extremities contribute substantially to front crawl load-velocity profiles of highly trained swimmers. Higher sprint swimming speeds are associated with an efficient speed transfer from lower- and upper- to whole-body movement.

Modeling lactate threshold in young squad athletes: influence of sex, maximal oxygen uptake, and cost of running.

PURPOSE: This study aimed to investigate: 1. The influence of sex and age on the accuracy of the classical model of endurance performance, including maximal oxygen uptake ([Formula: see text]), its fraction (LT2%), and cost of running (CR), for calculating running speed at lactate threshold 2 (vLT2) in young athletes. 2. The impact of different CR determination methods on the accuracy of the model. 3. The contributions of [Formula: see text], LT2%, and CR to vLT2 in different sexes. METHODS: 45 male and 55 female young squad athletes from different sports (age: 15.4 ± 1.3 years; [Formula: see text]: 51.4 ± 6.8 [Formula: see text]) performed an incremental treadmill test to determine [Formula: see text], LT2%, CR, and vLT2. CR was assessed at a fixed running speed (2.8 [Formula: see text]), at lactate threshold 1 (LT1), and at 80% of [Formula: see text], respectively. RESULTS: Experimentally determined and modeled vLT2 were highly consistent independent of sex and age (ICC [Formula: see text] 0.959). The accuracy of vLT2 modeling was improved by reducing random variation using individualized CR at 80% [Formula: see text] (± 4%) compared to CR at LT1 (± 7%) and at a fixed speed (± 8%). 97% of the total variance of vLT2 was explained by [Formula: see text], LT2%, and CR. While [Formula: see text] and CR showed the highest unique (96.5% and 31.9% of total [Formula: see text], respectively) and common (- 31.6%) contributions to the regression model, LT2% made the smallest contribution (7.5%). CONCLUSION: Our findings indicate: 1. High accuracy of the classical model of endurance performance in calculating vLT2 in young athletes independent of age and sex. 2. The importance of work rate selection in determining CR to accurately predict vLT2. 3. The largest contribution of [Formula: see text] and CR to vLT2, the latter being more important in female athletes than in males, and the least contribution of LT2%.

The course of knee extensor strength after total knee arthroplasty: a systematic review with meta-analysis and -regression.

PURPOSE: Muscular strength loss and atrophy are postoperative complications. This systematic review with meta-analysis investigated the course of on knee extensor mass and strength from pre-surgery over total knee arthroplasty to rehabilitation and recovery. METHODS: A systematic literature search was conducted in PubMed (Medline), Cochrane Library (CINAHL, Embase) and Web of Science (until 29th of June 2022). Main inclusion criteria were ≥ 1 preoperative and ≥ 1 measurement ≥ 3-months post-operation and ≥ 1 objective assessment of quadriceps strength, muscle mass or neuromuscular activity, measured at both legs. Studies were excluded if they met the following criteria: further impairment of treated extremity or of the contralateral extremity; further muscle affecting disease, or muscle- or rehabilitation-specific intervention. The Robins-I tool for non-randomized studies, and the Cochrane Rob 2 tool for randomized controlled studies were used for risk of bias rating. Pre-surgery, 3 months, 6 months and 1 year after surgery data were pooled using random effects meta-analyses (standardized mean differences, SMD, Hedge's g) in contrast to the pre-injury values. RESULTS: 1417 studies were screened, 21 studies on 647 participants were included. Thereof, 13 were non-randomized controlled trails (moderate overall risk of bias in most studies) and 7 were randomized controlled trials (high risk of bias in at least one domain in most studies). Three (k = 12 studies; SMD = - 0.21 [95% confidence interval = - 0.36 to - 0.05], I2 = 4.75%) and six (k = 9; SMD = - 0.10 [- 0.28 to - 0.08]; I2 = 0%) months after total knee arthroplasty, a deterioration in the strength of the operated leg compared with the strength of the non-operated leg was observed. One year after surgery, the operated leg was stronger in all studies compared to the preoperative values. However, this increase in strength was not significant compared to the non-operated leg (k = 6, SMD = 0.18 [- 0.18 to 0.54], I2 = 77.56%). CONCLUSION: We found moderate certainty evidence that deficits in muscle strength of the knee extensors persist and progress until 3 months post-total knee arthroplasty in patients with end-stage knee osteoarthritis. Very low certainty evidence exists that preoperatively existing imbalance of muscle strength and mass in favor of the leg not undergoing surgery is not recovered within 1 year after surgery.

The Molecular Signature of High-intensity Training in the Human Body.

High-intensity training is becoming increasingly popular outside of elite sport for health prevention and rehabilitation. This expanded application of high-intensity training in different populations requires a deeper understanding of its molecular signature in the human body. Therefore, in this integrative review, cellular and systemic molecular responses to high-intensity training are described for skeletal muscle, cardiovascular system, and the immune system as major effectors and targets of health and performance. Different kinds of stimuli and resulting homeostatic perturbations (i. e., metabolic, mechanical, neuronal, and hormonal) are reflected, taking into account their role in the local and systemic deflection of molecular sensors and mediators, and their role in tissue and organ adaptations. In skeletal muscle, a high metabolic perturbation induced by high-intensity training is the major stimulus for skeletal muscle adaptation. In the cardio-vascular system, high-intensity training induces haemodynamic stress and deflection of the Ca 2+ handling as major stimuli for functional and structural adaptation of the heart and vessels. For the immune system haemodynamic stress, hormones, exosomes, and O2 availability are proposed stimuli that mediate their effects by alteration of different signalling processes leading to local and systemic (anti)inflammatory responses. Overall, high-intensity training shows specific molecular signatures that demonstrate its high potential to improve health and physical performance.

Influence of physical and psychological stress on decision-making performance of soccer referees.

Soccer referees have to make quick and accurate decisions while experiencing physical stress (i.e., fatigue) and psychological stress (i.e., pressure from the crowd). Researchers have examined the influence of physical and psychological stress on skilled referees' decision-making performance separately; however, referees usually experience both types of stress simultaneously. The aim of the study was to investigate the influence of both physical and psychological stress on skilled and less-skilled soccer referees' decision-making performance. To simulate the physical and psychological stress during a game, 25 referees were asked to make foul decisions while running on a treadmill and/or being exposed to auditory stress. Referees were more physically fatigued in the physical and psychologically stressed in the psychological stress condition. However, this only negatively influenced their decision-making performance in the video test during the submaximal physical stress condition, when compared to the resting condition. The results also indicate that the experienced referees learned to cope with fatigue and psychological stress regarding their cognitive processes. The effects seem to be differentially detrimental, depending on the league level of refereeing, but also whether physical and psychological stress are induced separately. The study protocol could help referees train in a simulated learning environment, besides on-field games.

Effects of Alternating Unilateral vs. Bilateral Resistance Training on Sprint and Endurance Cycling Performance in Trained Endurance Athletes: A 3-Armed, Randomized, Controlled, Pilot Trial.

ABSTRACT: Ji, S, Donath, L, and Wahl, P. Effects of alternating unilateral vs. bilateral resistance training on sprint and endurance cycling performance in trained endurance athletes: A 3-armed, randomized, controlled, pilot trial. J Strength Cond Res 36(12): 3280-3289, 2022-Traditional preparatory resistance training for cyclists mainly relies on simultaneous bilateral movement patterns. This lack of movement specificity may impede transfer effects to specific aerobic and anaerobic requirements on the bike. Hence, this study investigated the effects of resistance training in alternating unilateral vs. simultaneous bilateral movement pattern on strength and anaerobic as well as aerobic cycling performance indices. Twenty-four trained triathletes and cyclists (age: 31.1 ± 8.1 years; V̇ o2 max: 57.6 ± 7.1 ml·min -1 ·kg -1 ) were randomly assigned to either an alternating unilateral (AUL), a simultaneous bilateral (BIL) training group or a control group (CON). Ten weeks of resistance training (4 × 4-10 repetition maximum) were completed by both training groups, although CON maintained their usual training regimen without resistance training. Maximal strength was tested during isometric leg extension, leg curl, and leg press in both unilateral and bilateral conditions. To compare the transfer effects of the training groups, determinants of cycling performance and time to exhaustion at 105% of the estimated anaerobic threshold were examined. Maximal leg strength notably increased in both training groups (BIL: ∼28%; AUL: ∼27%; p < 0.01) but not in CON (∼6%; p > 0.54). A significant improvement in cycling time trial performance was also observed in both training groups (AUL: 67%; BIL: 43%; p < 0.05) but not for CON (37%; p = 0.43). Bilateral group exhibited an improved cycling economy at submaximal intensities (∼8%; p < 0.05) but no changes occurred in AUL and CON (∼3%; p > 0.24). While sprint cycling performance decreased in CON (peak power: -6%; acceleration index: -15%; p < 0.05), improvement in favor of AUL was observed for acceleration abilities during maximal sprinting (20%; d = 0.5). Our pilot data underpin the importance of resistance training independent of its specific movement pattern both for improving the endurance cycling performance and maximal leg strength. Further research should corroborate our preliminary findings on whether sprint cycling benefits favorably from AUL resistance training.

Feasibility and suitability of a graded exercise test in patients with aggressive hemato-oncological disease.

PURPOSE: Physical activity promises to reduce disease-related symptoms and therapy-related side effects in patients suffering from aggressive lymphoma (L) or acute leukemia (AL). For an efficient training program, determination of patients' physical capacity with a purposive exercise test is crucial. Here, we evaluated the feasibility and suitability of a graded exercise test (GXT) frequently applied in patients suffering from solid tumors by assessing whether patients achieved criteria for maximal exercise testing according to the American College of Sports Medicine (ACSM). METHODS: The GXT was performed by 51 patients with an aggressive L or AL prior to the start or in the earliest possible phase of high-dose chemotherapy, following a recommended protocol for cancer patients, starting at 20 Watts (W), with an increase of 10 W/min until volitional exhaustion. Subsequently, we investigated whether the following ACSM criteria were fulfilled: (1) failure of heart rate to increase despite increasing workload, (2) post-exercise capillary lactate concentration ≥ 8.0 mmol L-1, (3) rating of perceived exertion at exercise cessation > 17 on the 6-20 Borg Scale. RESULTS: Out of 51 patients, two, six, and 35 participants met the first, second, and third criterion, respectively. No relevant relationships between the completion of the criteria and patients' characteristics (e.g., gender, age) were found. CONCLUSION: Although results of this study suggest a general feasibility of the applied GXT, the ACSM criteria were not met by the majority of the participants. Therefore, this study raises doubts about the suitability of the GXT protocol and the ACSM criteria for this group of patients.

No Influence of Nonivamide-nicoboxil on the Peak Power Output in Competitive Sportsmen.

Recent studies have shown that the oxygenated hemoglobin level can be enhanced during rest through the application of nonivamide-nicoboxil cream. However, the effect of nonivamide-nicoboxil cream on oxygenation and endurance performance under hypoxic conditions is unknown. Therefore, the purpose of this study was to investigate the effects of nonivamide-nicoboxil cream on local muscle oxygenation and endurance performance under normoxic and hypoxic conditions. In a cross-over design, 13 athletes (experienced cyclists or triathletes [age: 25.2±3.5 years; VO2max 62.1±7.3 mL·min-1·kg-1]) performed four incremental exercise tests on the cycle ergometer under normoxic or hypoxic conditions, either with nonivamide-nicoboxil or placebo cream. Muscle oxygenation was recorded with near-infrared spectroscopy. Capillary blood samples were taken after each step, and spirometric data were recorded continuously. The application of nonivamide-nicoboxil cream increased muscle oxygenation at rest and during different submaximal workloads as well as during physical exhaustion, irrespective of normoxic or hypoxic conditions. Overall, there were no significant effects of nonivamide-nicoboxil on peak power output, maximal oxygen uptake or lactate concentrations. Muscle oxygenation is significantly higher with the application of nonivamide-nicoboxil cream. However, its application does not increase endurance performance.

Comparison and Performance Validation of Calculated and Established Anaerobic Lactate Thresholds in Running.

Background and Objectives: This study aimed to compare the calculated running velocity at the anaerobic lactate threshold (cLTAn), determined by a mathematical model for metabolic simulation, with two established threshold concepts (onset of blood lactate accumulation (OBLA; 4 mmol∙L-1) and modified maximal deviation method (mDmax)). Additionally, all threshold concepts were correlated with performance in different endurance running events. Materials and Methods: Ten sub-elite runners performed a 30 s sprint test on a cycle ergometer adjusted to an isokinetic mode set to a cadence of 120 rpm to determine maximal lactate production rate (VLamax), and a graded exercise test on a treadmill to determine maximal oxygen uptake (VO2max). Running velocities at OBLA, mDmax, and cLTAn were then compared with each other, and further correlated with running performance over various distances (3000 m, 5000 m, and 10,000 m). Results: The mean difference in cLTAn was -0.13 ± 0.43 m∙s-1 and -0.32 ± 0.39 m∙s-1 compared to mDmax (p = 0.49) and OBLA (p < 0.01), respectively. cLTAn indicated moderate to good concordance with the established threshold concepts (mDmax: ICC = 0.87, OBLA: ICC = 0.74). In comparison with other threshold concepts, cLTAn exhibited comparable correlations with the assessed running performances (cLTAn: r = 0.61-0.76, mDmax: r = 0.69-0.79, OBLA: r = 0.56-0.69). Conclusion: Our data show that cLTAn can be applied for determining endurance performance during running. Due to the consideration of individual physiological profiles, cLTAn offers a physiologically justified approach to assess an athlete's endurance performance.

Training Load Measures and Biomarker Responses during a 7-Day Training Camp in Young Cyclists-A Pilot Study.

Background and Objectives: During intense training periods, there is a high need to monitor the external and especially the internal training load in order to fine-tune the training process and to avoid overreaching or overtraining. However, data on stress reactions, especially of biomarkers, to high training loads in children and youth are rare. Therefore, in this study, we aimed to investigate the training load of youth athletes during a training camp using a multilevel approach. Materials and Methods: Six trained youth male cyclists performed a 7-day preseason training camp. To investigate the internal training load, every morning, minimally invasive "point-of-care testing" (POCT) devices were used to analyze the following biomarkers: creatine kinase (CK), blood urea nitrogen (BUN), albumin (Alb), bilirubin (Bil), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total protein (TP). Additionally, data of training load measures (HR: heart rate, RPE: rating of perceived exertion, sRPE: session-RPE, TRIMP: training impulse, intensity (RPE:HR), and load (sRPE:TRIMP) ratios), self-perception (person's perceived physical state, questionnaires on muscle soreness, and sleep quality), and measures of the autonomic nervous system (resting heart rate, heart rate variability) were collected. Two days before and after the training camp, subjects performed performance tests (Graded Exercise Test, Wingate Anaerobic Test, Counter Movement Jump). Results: Primarily, the biomarkers CK, BUN, and Alb, as well as the self-perception showed moderate to large load-dependent reactions during the 7-day training camp. The biomarkers returned to baseline values two days after the last training session. Power output at lactate threshold showed a small increase, and no changes were found for other performance parameters. Conclusions: The study suggests that a multilevel approach is suitable to quantify the internal training load and that different parameters can be used to control the training process. The biomarkers CK, BUN, and Alb are suitable for objectively quantifying the internal training load. The self-perception provides additional subjective information about the internal training load.

Reverse lactate threshold test accurately predicts maximal lactate steady state and 5 km performance in running.

This study evaluated the accuracy of the reverse lactate threshold (RLT) and the onset of blood lactate accumulation (OBLA; 4 mmol·L-1) to determine the running speed at the maximal lactate steady state (MLSS) and 5 km running performance in a field test approach. Study 1: 16 participants performed an RLT test, and 2 or more constant-speed tests, lasting 30 minutes each, to determine running speed at the MLSS. Study 2: 23 participants performed an RLT test and a 5000 m all-out run as an indicator of performance. The RLT test consisted of an initial lactate-priming segment, in which running speed was increased stepwise up to ~5% above the estimated MLSS, followed by a reverse segment in which speed was decreased by 0.1 m·s-1 every 180 s. RLT was determined using the highest lactate equivalent ([La-]/running speed) during the reverse segment. OBLA was determined during the priming segment and was set at a value of 4 mmol∙L1. The mean difference in MLSS was +0.06 ± 0.05 m·s-1 for RLT, and +0.13 ± 0.23 m·s-1 for OBLA. OBLA showed a good concordance with the MLSS (ICC = 0.83), whereas RLT revealed excellent concordance with the MLSS with an ICC = 0.98. RLT showed a very high correlation with 5000 m speed (r = 0.97). The RLT exhibited exceptional agreement to MLSS and 5000 m running performance. Due to this high accuracy, especially concerning the small intraindividual differences, the RLT test may be superior to common threshold concepts. Further research is needed to evaluate its sensitivity during the training process.

Cellular immune response to acute exercise: Comparison of endurance and resistance exercise.

OBJECTIVES: Exercise-induced cellular mobilization might play a role in treatment and prevention of several diseases. However, little is known about the impact of different exercise modalities on immune cell mobilization and clinical cellular inflammation markers. Therefore, the present study aimed to investigate differences between acute endurance exercise (EE) and resistance exercise (RE) on cellular immune alterations. METHODS: Twenty-four healthy men conducted an acute EE (cycling at 60% of peak power output) and RE (five exercise machines at 70% of the one-repetition maximum) session lasting 50 minutes in randomized order. Blood samples were collected before, after and one hour after exercise cessation. Outcomes included counts and proportions of leukocytes, neutrophils (NEUT), lymphocytes (LYM), LYM subsets, CD4/CD8 ratio, and the clinical cellular inflammation markers NEUT/LYM ratio (NLR), platelets/LYM ratio (PLR), and systemic immune inflammation index (SII). RESULTS: Alterations in all outcomes were revealed except for CD8+ T cells, CD4/CD8 ratio, NLR, and PLR. EE induced a stronger cellular immune response and provoked alterations in more immune cell populations than RE. SII was altered only after EE. CONCLUSION: An acute EE session causes a stronger mobilization of immune cells than RE. Additionally, SII represents an integrative marker to depict immunological alterations.

The physiological effects of daily cold-water immersion on 5-day tournament performance in international standard youth field-hockey players.

PURPOSE: This study examined the effects of daily post-exercise cold-water immersion (CWI) on match performance, perceptual recovery, and biomarkers of muscle damage and metabolic load during a 5-day international tournament of elite youth field-hockey players. METHODS: The entire German under-18 national squad (n = 18) was randomly assigned to a daily CWI- (5-min at ~ 6 °C; excluding the head; n = 9) or passive recovery (CON; n = 9) intervention. Training and match performance were assessed using a GPS-tracking system and perceived exertion (RPE). Daily ratings of delayed onset muscle soreness (DOMS), perceived stress and recovery, quality of sleep, heart-rate recovery and serum creatine kinase (CK), lactate dehydrogenase, and urea nitrogen were also recorded. Repeated-sprint ability (RSA) and counter-movement jump (CMJ) were carried out on days 1 and 5. RESULTS: There was no significance between intervention differences in time-on pitch, total distance, velocity zones, and accelerometer-base parameters during match performance (all p > 0.05). DOMS (p < 0.01), RPE (p < 0.01), and CK (p < 0.01) were significantly elevated over the course of the tournament; however, no between-intervention effects were observed (all p > 0.05). Both groups were able to maintain RSA and CMJ (all p > 0.05). CONCLUSION: In conclusion, daily post-exercise CWI did not improve match performance, perceptual recovery, or biomarkers of muscle damage and metabolic load in elite youth field-hockey players.

Acute Impact of Recovery on the Restoration of Cellular Immunological Homeostasis.

In view of the growing amount of (intense) training in competitive sports, quick recovery plays a superior role in performance restoration. The aim of the present study was to compare the effects of active versus passive recovery during high-intensity interval training (HIIT) and sprint interval training (SIT) protocols on acute alterations of circulating blood cells. Twelve male triathletes/cyclists performed 1) a HIIT consisting of 4×4 min intervals, 2) a SIT consisting of 4×30s intervals, separated by either active or passive recovery. Blood samples were collected immediately before and at 0', 30', 60' and 180' (minutes) post-exercise. Outcomes comprised leukocytes, lymphocytes, neutrophils, mixed cell count, platelets, cellular inflammation markers (neutrophil/lymphocyte-ratio (NLR), platelet/lymphocyte-ratio (PLR)), and the systemic immune-inflammation index (SII). In view of HIIT, passive recovery attenuated the changes in lymphocytes and neutrophils compared to active recovery. In view of SIT, active recovery attenuated the increase in leukocytes, lymphocytes and absolute mixed cell count compared to passive recovery. Both protocols, independent of recovery, significantly increased NLR, PLR and SII up to 3h of recovery compared to pre-exercise values. The mode of recovery influences short-term alterations in the circulating fraction of leukocytes, lymphocytes, neutrophils and the mixed cell count, which might be associated with different hormonal and metabolic stress responses due to the mode of recovery.

Effects of psychosocial and physical stress on lactate and anxiety levels.

Both intense physical activity and potent psychosocial stressors increase blood lactate. Raising lactate levels by infusing the chemical can have an anxiogenic effect. Here, we compare the relationship between changes in lactate and anxiety levels resulting from two standardized stressors. We investigated the effects of the Multiple Wingate All-Out Performance Test (WG), a strong physical stressor, and the Trier Social Stress Test (TSST), a well-documented psychosocial stressor, in 32 healthy young men using a crossover design. Before and after each stressor, venous blood was analyzed for lactate levels and the State-Trait-Anxiety Inventory (STAI) was given. Both stressors raised both lactate and anxiety significantly above their baseline levels. While the rise in lactate was much higher for the WG than for the TSST, the rises in anxiety were nearly equal. Individual fitness did not influence the results for lactate or anxiety. No significant relation between lactate and anxiety changes were found. Thus, our results as well as the literature suggest that lactate is an important variable for understanding the impact of sport participation.

Aqua cycling for immunological recovery after intensive, eccentric exercise.

PURPOSE: Alterations in immunological homeostasis induced by acute exercise have been frequently reported. In view of the growing amount of repetitive exercise stimuli in competitive sports, quick recovery plays a superior role. Therefore, we examined whether aqua cycling affects cellular immunological recovery. METHODS: After performing 300 countermovement jumps with maximal effort male sport students (n = 20; 24.4 ± 2.2 years) were randomized into either an aqua cycling (AC) or a passive recovery (P) group. AC pedaled in chest-deep water without resistance, while P lay in a supine position. Each recovery protocols lasted 30 min. Blood samples were taken at Baseline, Post-exercise, Post-recovery and 1 h (h), 2 h, 4 h, 24 h, 48 h and 72 h after recovery. Outcomes comprised white blood cell (WBC) counts, lymphocyte (LYM) counts and LYM subsets (CD4/CD8 ratio). Additionally, cellular inflammation markers (neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and systemic immune-inflammation index (SII)) were calculated. RESULTS: In both groups, WBC, NLR and SII were significantly increased compared to Baseline up to and including 4 h after recovery. Significant interaction effects were found for WBC (Post-recovery, 2 h and 4 h), NLR (Post-recovery), SII (Post-recovery) and CD4/CD8 ratio (2 h) with values of AC being higher than of P. CONCLUSIONS: Interestingly, AC provoked a stronger but not prolonged immunological disturbance than P. NLR and SII may present simple, more integrative markers to screen exercise-induced alterations in immune homeostasis/recovery in athletes and clinical populations. More research is warranted to elucidate the clinical and practical relevance of these findings.

Higher Accuracy of the Lactate Minimum Test Compared to Established Threshold Concepts to Determine Maximal Lactate Steady State in Running.

This study evaluated the accuracy of the lactate minimum test, in comparison to a graded-exercise test and established threshold concepts (OBLA and mDmax) to determine running speed at maximal lactate steady state. Eighteen subjects performed a lactate minimum test, a graded-exercise test (2.4 m·s-1 start,+0.4 m·s-1 every 5 min) and 2 or more constant-speed tests of 30 min to determine running speed at maximal lactate steady state. The lactate minimum test consisted of an initial lactate priming segment, followed by a short recovery phase. Afterwards, the initial load of the subsequent incremental segment was individually determined and was increased by 0.1 m·s-1 every 120 s. Lactate minimum was determined by the lowest measured value (LMabs) and by a third-order polynomial (LMpol). The mean difference to maximal lactate steady state was+0.01±0.14 m·s-1 (LMabs), 0.04±0.15 m·s-1 (LMpol), -0.06±0.31 m·s1 (OBLA) and -0.08±0.21 m·s1 (mDmax). The intraclass correlation coefficient (ICC) between running velocity at maximal lactate steady state and LMabs was highest (ICC=0.964), followed by LMpol (ICC=0.956), mDmax (ICC=0.916) and OBLA (ICC=0.885). Due to the higher accuracy of the lactate minimum test to determine maximal lactate steady state compared to OBLA and mDmax, we suggest the lactate minimum test as a valid and meaningful concept to estimate running velocity at maximal lactate steady state in a single session for moderately up to well-trained athletes.

Reply to: Could superimposed electromyostimulation be an effective training to improve aerobic and anaerobic capacity? Methodological considerations for its development.

In the present reply, we would like to put forward our perspective on the points raised by Amaro-Gahete et al. The main concerns addressed by the authors deal with the stimulation modalities applied in our study, compared to the results of Miyamoto et al. (Eur J Sports Sci 16(8):1104-1110, 2016), who showed an increase in the first ventilatory threshold and VO2peak after 16 × 30 min low-frequency neuromuscular electrical stimulation (NMES). We have to emphasize that both mentioned studies generally follow different approaches, and that the different outcomes might not only be related to stimulation modalities. Even the results of different studies, which used sole NMES is not consistent. Especially the relevance of local metabolic and ultrastructural adaptations in skeletal muscle for the translation to functional performance, that is particularly important for sport and activities, is not always investigated in these studies.

Chronic effects of superimposed electromyostimulation during cycling on aerobic and anaerobic capacity.

PURPOSE: To examine if chronic endurance training by means of simultaneously applied, superimposed electromyostimulation (EMS) can be used to improve performance and physiological core parameters compared to the traditional cycling. METHODS: Twenty-one male subjects (VO2peak 55.2 ± 5.1 ml min- 1 kg- 1) were assigned to either a cycling (C) or cycling with superimposed EMS (C + E) group. Before and after the 4-week training period, including 14 sessions of moderate cycling [60 min at 60% peak power output (PPO)], participants performed a 20-min time-trial, a step test to exhaustion, a 30-s isokinetic sprint test, and maximum force- and power-tests. Markers of muscle damage and metabolic condition were assessed during the training period. RESULTS: Step test results revealed increases in PPO, VO2peak, lactate threshold 1, and the anaerobic threshold for both groups (p < 0.05). Mean power output (MPO) obtained from time-trial was improved in C and C + E (p < 0.05). Isokinetic sprint test revealed increased PPO in both groups, whereas MPO was only changed in C (p < 0.05). Strength parameters were unaffected. Although metabolic stimuli and markers of muscle damage were higher in C + E compared to C, improvements of endurance performance and capacity were not significantly different between C and C + E. CONCLUSIONS: Despite a higher metabolic, respiratory, and muscular demand, chronic additional superimposed EMS during cycling does not result in superior improvements in endurance and strength performance compared to the traditional cycling.