Comparison of anaerobic speed reserve and maximal aerobic speed methods to prescribe short format high-intensity interval training.

The purpose of the study was to compare the degree of intersubject variability in the cardiorespiratory, metabolic, and perceptual responses to high-intensity interval training (HIIT) prescribed based on the relative anaerobic speed reserve (ASR) or maximal aerobic speed (MAS) and to identify the optimal % ASR for execution of such HIIT. Seventeen male physical education students (age: 23.6 ± 1.1 years, height: 180.2 ± 5.9, body mass: 78.3 ± 8.1 kg; % body fat: 14.3 ± 2.7%) volunteered to execute three randomly scheduled 10-min HIIT exercises at 110% vVO2max , Δ15% ASR, or Δ25% ASR. Analysis of variance for repeated measures and the least significant difference post-hoc test were used to compare the physiological responses and the mean of individual residuals between the training sessions. The coefficients of variation (CV) of time spent ≥90% of maximal oxygen uptake (VO2max ) and maximal heart rate (HRmax ), peak VO2 , mean VO2 , peak HR, mean HR, blood lactate [La], and rating of perceived exertion (RPE) were 48.7%, 35.9%, 9.3%, 7%, 3.5%, 4.8%, 32%, and 16.9% during 110% vVO2max , 47.2%, 31%, 7.5%, 6.7%, 3.9%, 4.6%, 24.2%, and 14.6% during Δ15% ASR, and 48.1%, 31.5%, 7.6%, 8.4%, 3.6%, 4.1%, 20.2%, and 3.4% during Δ25% ASR session, respectively. Only the residuals in RPE were significantly (p < 0.001) higher in 110% vVO2max and Δ15% ASR in comparison to Δ25% ASR. Time spent ≥90% HRmax /VO2max was maximized during Δ15% ASR session, albeit this was not significantly different from other sessions. The ASR-based method leads to reduced CVs of physiological and perceptual responses during 10-min HIIT; however, only reductions in [La] and RPE may be considered practically meaningful. Practitioners can use vVO2max for prescription of 10-min HIIT session comprised of 15-s work and passive recovery intervals.

Validation of session ratings of perceived exertion for quantifying training load in karate kata sessions.

This study was intended to investigate the associations between session Ratings of Perceived Exertion (sRPE) and Edwards' training load (TL) and Banister training impulse (TRIMP) in order to determine the validity of the sRPE method for TL assessment in karate kata discipline. Eight elite karate kata athletes, members of the national karate team, took part in this study. A multistage 20 m shuttle run test was performed to determine maximal heart rate (HRmax). Subsequently, the subjects performed 3 different kata training sessions separated by minimally 48 hours. To calculate Edwards TL, Banister TRIMP and sRPE, heart rate (HR) was continuously monitored during the sessions and RPE of the entire session was collected 30 minutes after each training session. The Pearson correlation coefficient (r) was used for determining associations between TL variables. Edwards TL (p = 0.064) and Banister TRIMP (p = 0.102) were not, but sRPE was significantly different between each training session (p < 0.001). There were no significant correlations between sRPE and Edwards TL (r = 0.53, p = 0.18) or Banister TRIMP (r = 0.13, p = 0.77) when data from all training sessions were pooled. A significant correlation was obtained between sRPE and Edwards TL (r = 0.71, p = 0.04) in situational training session, whereas in technical training session sRPE was significantly correlated with Banister TRIMP (r = 0.82, p = 0.01). HR-based methods for TL assessment are not able to discriminate between kata training sessions and, therefore, sRPE may be more useful for coaches to monitor TL in karate kata athletes.

"Falling Behind," "Letting Go," and Being "Outsprinted" as Distinct Features of Pacing in Distance Running.

INTRODUCTION: In distance running, pacing is characterized by changes in speed, leading to runners dropping off the leader's pace until a few remain to contest victory with a final sprint. Pacing behavior has been well studied over the last 30 years, but much remains unknown. It might be related to finishing position, finishing time, and dependent on critical speed (CS), a surrogate of physiologic capacity. We hypothesized a relationship between CS and the distance at which runners "fell behind" and "let go" from the leader or were "outsprinted" as contributors to performance. METHODS: 100-m split times were obtained for athletes in the men's 10,000-m at the 2008 Olympics (N = 35). Split times were individually compared with the winner at the point of "falling behind" (successive split times progressively slower than the winner), "letting go" (large increase in time for distance compared with winner), or "outsprinted" (falling behind despite active acceleration) despite being with the leader with 400 m remaining. RESULTS: Race times ranged between 26:55 and 29:23 (world record = 26:17). There were 3 groups who fell behind at ∼1000 (n = 11), ∼6000 (n = 16), and ∼9000 m (n = 2); let go at ∼4000 (n = 10), ∼7000 (n = 14), and ∼9500 m (n = 5); or were outkicked (n = 6). There was a moderate correlation between CS and finishing position (r = .82), individual mean pace (r = .79), "fell behind" distance (r = .77), and "let go" distance (r = .79). D' balance was correlated with performance in the last 400 m (r = .87). CONCLUSIONS: Athletes displayed distinct patterns of falling behind and letting go. CS serves as a moderate predictor of performance and final placing. Final placing during the sprint is related to preservation of D' balance.

The Fine-Tuning Approach for Training Monitoring.

PURPOSE: Monitoring is a fundamental part of the training process to guarantee that the programmed training loads are executed by athletes and result in the intended adaptations and enhanced performance. A number of monitoring tools have emerged during the last century in sport. These tools capture different facets (eg, psychophysiological, physical, biomechanical) of acute training bouts and chronic adaptations while presenting specific advantages and limitations. Therefore, there is a need to identify what tools are more efficient in each sport context for better monitoring of training process. METHODS AND RESULTS: We present and discuss the fine-tuning approach for training monitoring, which consists of identifying and combining the best monitoring tools with experts' knowledge in different sport settings, designed to improve (1) the control of actual training loads and (2) understanding of athletes' training adaptations. Instead of using single-tool approaches or merely subjective decision making, the identification of the best combination of monitoring tools to assist experts' decisions in each specific context (ie, triangulation) is necessary to better understand the link between acute and chronic adaptations and their impact on health and performance. Future studies should elaborate on the identification of the best combination of monitoring tools for each specific sport setting. CONCLUSION: The fine-tuning monitoring approach requires the simultaneous use of several valid and practical tools, instead of a single tool, to improve the effectiveness of monitoring practices when added to experts' knowledge.

Effects of a training program for special operations battalion on soldiers' fitness characteristics.

The aim of this study was to investigate the effects of special operations battalion (SOB) training program on soldiers' fitness parameters. The research was conducted on a sample of 25 members (mean ± SD: age 27.93 ± 5.12 years, height 178.64 ± 6.91 cm, body mass 81.42 ± 9.18 kg) of the Croatian Armed Forces for SOB, divided into control and experimental groups. Total duration of the SOB basic training was 62 days. The sample of variables consists of 12 tests for the assessment of fitness characteristics, 2 tests for functional capacity, and 18 morphological measures. Morphological parameters were measured according to the instructions of the International Biological Program. Fitness characteristics were measured with the following tests: 1-kg medicine ball throw from a seated position, standing broad jump (SBJ), relative sergeant test, 20-m sprint, the maximum thrust from the bench, push-ups in 2 minutes (PU(2minutes)), sit-ups in 2 minutes (SU(2minutes)), pull-ups (PU), thrust from the bench with 70% of body weight (BP(70%)), crawling and jumping, agility test 93639 with turn (A9-3-6-3-9), and sit and reach. Functional abilities were evaluated with 2 tests: 3,200 m running (SK3200) and 300 yards running (MBI3Y). There was a statistically significant difference in a set of fitness characteristics variables analyzed between the 2 groups in initial and final measurements in the multivariate level. Analyzing the results of t-test, differences of variables, it was evident that the difference after the SOB program occurred in 7 variables in the experimental group: SBJ, PU2minutes, SU2minutes, PU, BP70%, MBI3Y, and SK3200. Basic training for SOB during 8 weeks has produced significant burnout of the body for the participants who have completed their training. This led to a reduction in fitness performance manifested through the tested variables.

An Examination and Critique of Subjective Methods to Determine Exercise Intensity: The Talk Test, Feeling Scale, and Rating of Perceived Exertion.

Prescribing exercise intensity is crucial in achieving an adequate training stimulus. While numerous objective methods exist and are used in practical settings for exercise intensity prescription, they all require anchor measurements that are derived from a maximal or submaximal graded exercise test or a series of submaximal or supramaximal exercise bouts. Conversely, self-reported subjective methods such as the Talk Test (TT), Feeling Scale (FS) affect rating, and rating of perceived exertion (RPE) do not require exercise testing prior to commencement of the exercise training and therefore appear as more practical tools for exercise intensity prescription. This review is intended to provide basic information on reliability and construct validity of the TT, FS, and RPE measurements to delineate intensity domains. The TT and RPE appear to be valid measures of both the ventilatory threshold and the respiratory compensation threshold. Although not specifically examined, the FS showed tendency to demarcate ventilatory threshold, but its validity to demarcate the respiratory compensation threshold is limited. Equivocal stage of the TT, RPE of 10-11, and FS ratings between fairly good (+ 1) and good (+ 3) are reflective of the ventilatory threshold, while negative stage of the TT, RPE of 13-15, and FS ratings around neutral (0) are reflective of the respiratory compensation threshold. The TT and RPE can effectively be used to elicit homeostatic disturbances consistent with the moderate, heavy, and severe intensity domains, while physiological responses to constant FS ratings show extensive variability around ventilatory threshold to be considered effective in demarcating transition between moderate and heavy intensity domains.

Simple Approach to Defining Training Intensity in Endurance Runners.

Training intensity distribution is important to training program design. The zones 1 to 2 boundary can be defined by the Talk Test and the rating of perceived exertion. The zones 2 to 3 boundary can be defined by respiratory gas exchange, maximal lactate steady state, or, more simply, by critical speed (CS). The upper boundary of zone 3 is potential defined by the velocity at maximum oxygen uptake (vVO2max), although no clear strategy has emerged to categorize this intensity. This is not normally definable outside the laboratory. PURPOSE: This study predicts vVO2max from CS, determined from 1 (1.61 km) and 2 (3.22 km) citizen races in well-trained runners. METHODS: A heterogeneous group of well-trained runners (N = 22) performed 1- and 2-mile races and were studied during submaximal and maximal treadmill running to measure oxygen uptake, allowing computation of vVO2max. This vVO2max was compared with CS. RESULTS: vVO2max (4.82 [0.53] m·s-1) was strongly correlated with CS (4.37 [0.49] m·s-1; r = .84, standard error of estimate [SEE] = 0.132 m·s-1), 1-mile speed (5.09 [0.51] m·s-1; r = .84, SEE = 0.130 m·s-1), and 2-mile speed (4.68 [0.49] m·s-1; r = .86, SEE = 0.120 m·s-1). CONCLUSIONS: CS, calculated from 2 citizen races (or even training time trials), can be used to make reasonable estimates of vVO2max, which can be used in the design of running training programs.

COVID-19 Lockdown: A Global Study Investigating the Effect of Athletes' Sport Classification and Sex on Training Practices.

PURPOSE: To investigate differences in athletes' knowledge, beliefs, and training practices during COVID-19 lockdowns with reference to sport classification and sex. This work extends an initial descriptive evaluation focusing on athlete classification. METHODS: Athletes (12,526; 66% male; 142 countries) completed an online survey (May-July 2020) assessing knowledge, beliefs, and practices toward training. Sports were classified as team sports (45%), endurance (20%), power/technical (10%), combat (9%), aquatic (6%), recreational (4%), racquet (3%), precision (2%), parasports (1%), and others (1%). Further analysis by sex was performed. RESULTS: During lockdown, athletes practiced body-weight-based exercises routinely (67% females and 64% males), ranging from 50% (precision) to 78% (parasports). More sport-specific technical skills were performed in combat, parasports, and precision (∼50%) than other sports (∼35%). Most athletes (range: 50% [parasports] to 75% [endurance]) performed cardiorespiratory training (trivial sex differences). Compared to prelockdown, perceived training intensity was reduced by 29% to 41%, depending on sport (largest decline: ∼38% in team sports, unaffected by sex). Some athletes (range: 7%-49%) maintained their training intensity for strength, endurance, speed, plyometric, change-of-direction, and technical training. Athletes who previously trained ≥5 sessions per week reduced their volume (range: 18%-28%) during lockdown. The proportion of athletes (81%) training ≥60 min/session reduced by 31% to 43% during lockdown. Males and females had comparable moderate levels of training knowledge (56% vs 58%) and beliefs/attitudes (54% vs 56%). CONCLUSIONS: Changes in athletes' training practices were sport-specific, with few or no sex differences. Team-based sports were generally more susceptible to changes than individual sports. Policy makers should provide athletes with specific training arrangements and educational resources to facilitate remote and/or home-based training during lockdown-type events.

Training During the COVID-19 Lockdown: Knowledge, Beliefs, and Practices of 12,526 Athletes from 142 Countries and Six Continents.

OBJECTIVE: Our objective was to explore the training-related knowledge, beliefs, and practices of athletes and the influence of lockdowns in response to the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: Athletes (n = 12,526, comprising 13% world class, 21% international, 36% national, 24% state, and 6% recreational) completed an online survey that was available from 17 May to 5 July 2020 and explored their training behaviors (training knowledge, beliefs/attitudes, and practices), including specific questions on their training intensity, frequency, and session duration before and during lockdown (March-June 2020). RESULTS: Overall, 85% of athletes wanted to "maintain training," and 79% disagreed with the statement that it is "okay to not train during lockdown," with a greater prevalence for both in higher-level athletes. In total, 60% of athletes considered "coaching by correspondence (remote coaching)" to be sufficient (highest amongst world-class athletes). During lockdown, < 40% were able to maintain sport-specific training (e.g., long endurance [39%], interval training [35%], weightlifting [33%], plyometric exercise [30%]) at pre-lockdown levels (higher among world-class, international, and national athletes), with most (83%) training for "general fitness and health maintenance" during lockdown. Athletes trained alone (80%) and focused on bodyweight (65%) and cardiovascular (59%) exercise/training during lockdown. Compared with before lockdown, most athletes reported reduced training frequency (from between five and seven sessions per week to four or fewer), shorter training sessions (from ≥ 60 to < 60 min), and lower sport-specific intensity (~ 38% reduction), irrespective of athlete classification. CONCLUSIONS: COVID-19-related lockdowns saw marked reductions in athletic training specificity, intensity, frequency, and duration, with notable within-sample differences (by athlete classification). Higher classification athletes had the strongest desire to "maintain" training and the greatest opposition to "not training" during lockdowns. These higher classification athletes retained training specificity to a greater degree than others, probably because of preferential access to limited training resources. More higher classification athletes considered "coaching by correspondence" as sufficient than did lower classification athletes. These lockdown-mediated changes in training were not conducive to maintenance or progression of athletes' physical capacities and were also likely detrimental to athletes' mental health. These data can be used by policy makers, athletes, and their multidisciplinary teams to modulate their practice, with a degree of individualization, in the current and continued pandemic-related scenario. Furthermore, the data may drive training-related educational resources for athletes and their multidisciplinary teams. Such upskilling would provide athletes with evidence to inform their training modifications in response to germane situations (e.g., COVID related, injury, and illness).

How reliable are the equations for predicting maximal heart rate values in military personnel?

OBJECTIVES: The purpose of this study was to evaluate the validity and reliability of equations for predicting maximal values of heart rate (HR) in military personnel. METHODS: Five hundred and nine members of the Croatian Armed Forces (age 29.1 +/- 5.5 years; height 180.1 +/- 6.6 cm; body mass 83.4 +/- 11.3 kg; maximal oxygen uptake [VO2(max)] 49.7 +/- 6.9 mL O2/kg/min) were tested. The graded exercise test with gas exchange measurements was used to determine VO2(max) and maximum HR (HR(max)). The analysis of variance was used to determine the differences between the equations to calculate HR(max). RESULTS: The analysis of variance yielded statistically significant differences between seven HR equations (p < 0.05). The values from Stevens Creek's (HR(max) = 205 - [age/2]) and Fox and Haskell's (HR(max) = 220 - age) equations had the highest correlation with the HRmax obtained by the graded exercise test. CONCLUSION: The authors recommend using the HR(max) values from the Stevens Creek and the Fox and Haskell equations for the purpose of training, testing, and daily exercise routine in military personnel.

Impact of body composition on performance in fitness tests among personnel of the Croatian navy.

The purpose of this study was to determine the impact of body weight on fitness tests among the personnel of the Croatian navy. Forty two naval personnel (age 27 +/- 4.1 years; body mass 86.2 +/- 4.9 kg; height 184.6 +/- 7.4 cm; body fat percentage 17.3 +/- 5.2) participated in this study. In order to evaluate the fitness of the naval servicemen, we applied a testing procedure that included measurements of 7 fitness tests and 15 body anthropometric tests. A negative correlation was found between the body fat percentage and all the analyzed sprint tests and three anaerobic power tests (r), SP5 (r = -0.42), SP10 (r = -0.51), SP20 (r = -0.53), SJ (r = -0.45), CM (r = -0.57), SLJ (r = -0.67). Also a negative correlation was found between the body fat percentage and VO2(max) (r = -0.44). A positive correlation was found between the sprint test and the power performance test and thigh and calf girth. Spiriting ability is influenced by the strength of a person. This is one of the reasons why we found a positive correlation between the sprint test (SP5, SP10 and SP20) and thigh and calf girth. In this study we found a negative correlation between body fat percentages and all the sprint tests and three anaerobic power tests and VO2(max). The ectomorph somatotypes have positive correlations with all variables. The mesomorph somatotypes have the greatest positive correlations with all variables. The endomorph somatotypes have negative correlations with all variables. According to the body composition of Croatian naval servicemen we can conclude that they need a sufficient level of strength and endurance for everyday tasks. The effectiveness of a weight-management program is determined by the success of the participants in losing the necessary amount of weight and being able to maintain that weight loss. This requires long-term tracking of these individuals in a naval environment.

Applicability of Field Aerobic Fitness Tests in Soccer: Which One to Choose?

A desire to make fitness testing cheaper and easier to conduct in a team-sport setting has led to the development of numerous field aerobic fitness tests. This has contributed to a growing confusion among strength and conditioning coaches about which one to use. The main aim of this narrative review was to examine the reliability, validity, sensitivity and usefulness of the commonly used field aerobic fitness tests and to provide practical guidelines for their use in soccer. The University of Montreal track test (UMTT) and Vam Eval test seem the best options for estimation of maximal oxygen uptake (VO2max) while the highest signal-to-noise ratio of the 30-15 intermittent fitness test (30-15IFT) suggests its superior sensitivity to track changes in fitness. The UMTT and 30-15IFT are the best solutions for prescription of long and short high-intensity interval training sessions, respectively. All field tests mostly present with marginal usefulness, but the smallest worthwhile change for UMTT or Vam Eval test, Yo-YoIRT2 and 30-15IFT are smaller than their stage increment making the improvement of only one stage in the test performance already worthwhile. Strength and conditioning coaches are advised to choose the test based on their specific purpose of testing.

25 Years of Session Rating of Perceived Exertion: Historical Perspective and Development.

The session rating of perceived exertion (sRPE) method was developed 25 years ago as a modification of the Borg concept of rating of perceived exertion (RPE), designed to estimate the intensity of an entire training session. It appears to be well accepted as a marker of the internal training load. Early studies demonstrated that sRPE correlated well with objective measures of internal training load, such as the percentage of heart rate reserve and blood lactate concentration. It has been shown to be useful in a wide variety of exercise activities ranging from aerobic to resistance to games. It has also been shown to be useful in populations ranging from patients to elite athletes. The sRPE is a reasonable measure of the average RPE acquired across an exercise session. Originally designed to be acquired ∼30 minutes after a training bout to prevent the terminal elements of an exercise session from unduly influencing the rating, sRPE has been shown to be temporally robust across periods ranging from 1 minute to 14 days following an exercise session. Within the training impulse concept, sRPE, or other indices derived from sRPE, has been shown to be able to account for both positive and negative training outcomes and has contributed to our understanding of how training is periodized to optimize training outcomes and to understand maladaptations such as overtraining syndrome. The sRPE as a method of monitoring training has the advantage of extreme simplicity. While it is not ideal for the precise recording of the details of the external training load, it has large advantages relative to evaluating the internal training load.

Muscle Damage During a Soccer World Cup Preparatory and Competition Period.

PURPOSE: To report creatine kinase ([CK]) responses during a soccer World Cup preparatory and first-leg period and to determine the influence of aerobic fitness on postmatch [CK] responses. METHODS: Eleven national-team players were analyzed in this study. A lactate threshold test was performed during the first 3 d, whereas fingertip blood was drawn most mornings (21 out of 30 d) for [CK] measurements. One-way repeated-measures analysis of variance was used for determining the effect of time on [CK] measurements, whereas Pearson correlation coefficient was used for assessing associations between the changes in [CK] and velocities associated with blood lactate concentrations of 2 (v2) and 4 mmol·L-1 (v4). RESULTS: Peak [CK] concentrations were consistently reached on the first day after the match with values of 474 (261), 520 (419), and 460 (126) U·L-1 but with no significant differences between them. [CK] concentrations returned to prematch values (331 [201] U·L-1) on the second day after the match. The change in [CK] concentration between prematch and postmatch day was largely correlated (r = .614, P = .044) with v2. CONCLUSIONS: Top-level soccer players display low levels of muscle damage during official tournaments, and they recover before the next match. Postmatch muscle damage is greater in players with higher aerobic endurance because this fitness quality enables them to execute high-intensity activities known to be a major contributor to muscle damage.

Beating Yourself: How Do Runners Improve Their Own Records?

BACKGROUND: Pacing studies suggest the distribution of effort for optimizing performance. Cross-sectional studies of 1-mile world records (WRs) suggest that WR progression includes a smaller coefficient of variation of velocity. PURPOSE: This study evaluates whether intraindividual pacing used by elite runners to break their own WR (1 mile, 5 km, and 10 km) is related to the evolution of pacing strategy. We provide supportive data from analysis in subelite runners. METHODS: Men's WR performances (with 400-m or 1-km splits) in 1 mile, 5 km, and 10 km were retrieved from the IAAF database (from 1924 to present). Data were analyzed relative to pacing pattern when a runner improved their own WR. Similar analyses are presented for 10-km performance in subelite runners before and after intensified training. RESULTS: WR performance was improved in 1 mile (mean [SD]: 3:59.4 [11.2] to 3:57.2 [8.6]), 5 km (13:27 [0:33] to 13:21 [0:33]), and 10 km (28:35 [1:27] to 28:21 [1:21]). The average coefficient of variation did not change in the 1 mile (3.4% [1.8%] to 3.6% [1.6%]), 5 km (2.4% [0.9%] to 2.2% [0.8%]), or 10 km (1.4% [0.1%] to 1.5% [0.6%]) with improved WR. When velocity was normalized to the percentage mean velocity for each race, the pacing pattern was almost identical. Very similar patterns were observed in subelite runners in the 10 km. When time improved from 49:20 (5:30) to 45:56 (4:58), normalized velocity was similar, terminal RPE increased (8.4 [1.6] to 9.1 [0.8]), coefficient of variation was unchanged (4.4% [1.1%] to 4.8% [2.1%]), and VO2max increased (49.8 [7.4] to 55.3 [8.8] mL·min-1·kg-1). CONCLUSION: The results suggest that when runners break their own best performances, they employ the same pacing pattern, which is different from when WRs are improved in cross-sectional data.

Generalized Approach to Translating Exercise Tests and Prescribing Exercise.

Although there is evidence supporting the benefit of regular exercise, and recommendations about exercise and physical activity, the process of individually prescribing exercise following exercise testing is more difficult. Guidelines like % heart rate (HR) reserve (HRR) require an anchoring maximal test and do not always provide a homogenous training experience. When prescribing HR on the basis of % HRR, rating of perceived exertion or Talk Test, cardiovascular/perceptual drift during sustained exercise makes prescription of the actual workload difficult. To overcome this issue, we have demonstrated a strategy for "translating" exercise test responses to steady state exercise training on the basis of % HRR or the Talk Test that appeared adequate for individuals ranging from cardiac patients to athletes. However, these methods depended on the nature of the exercise test details. In this viewpoint, we combine these data with workload expressed as Metabolic Equivalent Task (METs). We demonstrate that there is a regular stepdown between the METs during training to achieve the same degree of homeostatic disturbance during testing. The relationship was linear, was highly-correlated (r = 0.89), and averaged 71.8% (Training METs/Test METs). We conclude that it appears possible to generate a generalized approach to correctly translate exercise test responses to exercise training.

Intense Physical Exercise Induces an Anti-inflammatory Change in IgG N-Glycosylation Profile.

Exercise is known to improve many aspects of human health, including modulation of the immune system and inflammatory status. It is generally understood that exercise reduces inflammation, but there are missing links in terms of understanding the mechanisms as well as the differences between exercise modalities. N-glycosylation of immunoglobulin G (IgG) and total plasma proteins was previously shown to reflect changes in inflammatory pathways, which could provide valuable information to further clarify exercise effects. In order to further expand the understanding of the relationship between physical activity and inflammation, we examined the effect of intense exercise, in the form of repeated sprint training (RST), on IgG and total plasma proteins N-glycosylation in combination with traditionally used inflammation markers: C-reactive protein (CRP), interleukin 6 (IL-6), and leukocyte count. Twenty-nine male physical education students were separated into treatment (RST, N = 15) and control (N = 14) groups. The RST group completed a 6-week exercise protocol while the control group was instructed to refrain from organized physical activity for the duration of the study. Three blood samples were taken at different time points: prior to start of the training program, the final week of the exercise intervention (EXC), and at the end of the 4-week recovery period (REC). Following the end of the recovery period IgG N-glycosylation profiles showed anti-inflammatory changes in RST group compared to the control group, which manifested as a decrease in agalactosylated (p = 0.0473) and an increase in digalactosylated (p = 0.0473), and monosialylated (p = 0.0339) N-glycans. Plasma protein N-glycans didn't change significantly, while traditional inflammatory markers also didn't show significant change in inflammatory status. Observed results demonstrate the potential of intense physical exercise to reduce levels of systemic basal inflammation as well as the potential for IgG N-glycosylation to serve as a sensitive longitudinal systemic inflammation marker.