Meta-analysis of genomic variants in power and endurance sports to decode the impact of genomics on athletic performance and success.

Association between genomic variants and athletic performance has seen a high degree of controversy, as there is often conflicting data as far as the association of genomic variants with endurance, speed and strength is concerned. Here, findings from a thorough meta-analysis from 4228 articles exploring the association of genomic variants with athletic performance in power and endurance sports are summarized, aiming to confirm or overrule the association of genetic variants with athletic performance of all types. From the 4228 articles, only 107 were eligible for further analysis, including 37 different genes. From these, there were 21 articles for the ACE gene, 29 articles for the ACTN3 gene and 8 articles for both the ACE and ACTN3 genes, including 54,382 subjects in total, from which 11,501 were endurance and power athletes and 42,881 control subjects. These data show that there is no statistically significant association between genomic variants and athletic performance either for endurance or power sports, underlying the fact that it is highly risky and even unethical to make such genetic testing services for athletic performance available to the general public. Overall, a strict regulatory monitoring should be exercised by health and other legislative authorities to protect the public from such services from an emerging discipline that still lacks the necessary scientific evidence and subsequent regulatory approval.

Comprehensive analysis of performance, physiological, and perceptual responses during an entire sprint cross-country skiing competition.

PURPOSE: To investigate performance, physiological, and perceptual responses of an entire sprint cross-country skiing competition in the skating style. METHODS: Eighteen national-level male junior skiers participated in a simulated competition comprising an individual time trial (TT), followed by three heats (quarterfinals [QF], semifinals [SF], and final [F]). Participants' heart rate (HR) was continuously monitored while perceived readiness (RED, 1-10), rating of perceived exertion (RPE, 6-20), and blood lactate [La-] were assessed at standardized time points. RESULTS: The total duration and distance covered were 03:30 ± 00:06 h and 25.2 ± 2.9 km, respectively. The participants spent 02:19 ± 00:27 h > 60% of their maximal HR (HRmax) and 00:16 ± 00:04 h > 85% of HRmax. Average HR decreased from TT to F (89.3 ± 2.0% vs. 86.9 ± 3.0% of HRmax, P < 0.01). [La-] levels were highest before (4.6 ± 2.0 vs. 2.9 ± 1.2, 3.2 ± 2.0 and 2.5 ± 1.3 mmol·L-1, all P < 0.01) and after (10.8 ± 1.4 vs. 9.8 ± 1.6, 9.1 ± 1.8 and 8.7 ± 1.7 mmol·L-1, all P < 0.05) F compared to TT, QF, and SF, respectively. RED was lowest before F compared to TT, QF, and SF (6.6 ± 1.4 vs. 7.9 ± 1.1, 7.6 ± 1.1, and 7.4 ± 1.4, respectively, all P < 0.05) while RPE was highest after TT compared to QF, SF, and F (17.8 ± 0.9 vs. 15.1 ± 2.0, 16.5 ± 1.2 and 16.6 ± 1.8, respectively, all P < 0.01). The six best-performing skiers demonstrated higher RED before F (7.2 ± 0.9 vs. 5.3 ± 1.2, P < 0.05) and higher [La-] after F (11.2 ± 0.2 vs. 10.2 ± 0.3, mmol·L-1, P < 0.05) than lower-performing competitors. CONCLUSION: This study provides novel insights into physiological demands of an entire sprint cross-country skiing competition, which involves repeated 3-min high-intensity efforts interspersed with > 2 h (25 km) of low- to moderate-intensity exercise.

Highest oxygen consumption prediction: introducing variable theoretical proportional factors for different sports.

PURPOSE: The use of a fixed theoretical-proportional-factor (TPF15) is one of the indirect highest-oxygen-consumptions (HOC) assessment methods, but it may not accurately reflect the physiological differences across various sports (cycling-triathlon-running-football-multisport). The aim of this study is to evaluate the variability of TPF across different sports, proposing a series of sport-specific new TPF values for more accurate HOC estimation. METHODS: A sample of 340 adults (26.01 ± 7.18 years) performed a maximal-incremental-test using sport-specific-ergometers. HOC was considered for cycling  V ˙ O 2peak , whereas for the other investigated sports it was considered V ˙ O 2max . HOC was directly measured using a gas-analyzer, and TPF values were calculated using heart rate (HR): the ratio of HRmax/HRrest multiplied for the measured values of HOC. A one-way ANOVA was used to measure differences and Bland-Altman plots were constructed to compare predicted and actual  V ˙ O 2max / V ˙ O 2peak . RESULTS: Actual HOC was significantly greater than those predicted by the fixed TPF15 (P < 0.001). Sport-specific new TPF values ranged from 16.55 in multisport to 20.15 in cycling, consistently exceeding the old fixed TPF15, and predicting therefore better HOC. The new TPF exhibited a closer agreement with the directly measured V ˙ O 2max / V ˙ O 2peak  compared to the TPF15. Furthermore, the new TPF reduced the typical-measurement-error (14.94-17.78%) compared to TPF15 (15.63-24.13%). CONCLUSION: This study suggests that new TPF values predict V ˙ O 2max / V ˙ O 2peak  with higher accuracy compared to the traditional method. The use of HRmax and HRrest values allows to customize training programs for different athletes. Future research should focus on validating these findings across larger populations of athletes.

Relationships between training dose and record power outputs in professional road cyclists: insights and threats to validity.

Testing short-term (4-8 weeks) correlations between training dose and performance in professional road cyclists can help improve their training and performance. Multilevel mixed-modeling was used to correlate training dose (Time, Edwards' Trimp-eTRIMP, Training Stress Score-TSS, time spent in power output zones-Z1, Z2, Z3, Polarization Index-PI) and Record Power Output (RPO) over 1 minute (RPO1), 5 (RPO5), 20 (RPO20), and 40 minutes (RPO40) across four different time periods: training dose of the previous month with RPOs of the subsequent month (Monthly-analysis); training dose of the 8 weeks preceding All, Grand tours, One-day races with RPOs of these races. In Monthly-analysis, small positive relationships between all the training dose parameters, except for PI, and RPO1, RPO5, RPO20, RPO40 were found (p ≤ 0.001). In Grand tours analysis, Z3 showed a positive association with RPO40 (r: 0.45; p = 0.007, moderate) and was positively related to RPO1 and RPO5 (r between 0.32 and 0.34; p = 0.053-0.059, moderate). PI was small positively related to RPO1 (r = 0.29, p = 0.076, small). In One-day races analysis, eTRIMP was positively related to RPO5 (r = 0.30, p = 0.035, moderate), Z1 negatively related to RPO40 (r = -0.31, p = 0.031, moderate), PI positively related to RPO5 (r = 0.24, p = 0.068, small) and Z2 was negatively related to RPO20 (r = -0.29, p = 0.051, small). A certain degree of responsiveness to training dose exists in professional road cyclists. To improve RPOs an appropriate preparation pattern seems to be increasing high intensity training for Grand Tours and fostering high intensity and overall training load (eTRIMP and TSS) in a more polarized-fashion for one-day races. Systematic and precise data collection during training and racing is highly advocated.

Heart rate-based indices to detect parasympathetic hyperactivity in functionally overreached athletes. A meta-analysis.

Investigations into the sensitivity of heart rate-(HR) derived indices for tracking parasympathetic nervous system (PNS) changes in functionally overreached (F-OR) endurance-trained athletes have produced equivocal findings. Lack of clarity may be a result of methodological inconsistencies. Therefore, the aims of this systematic review and meta-analysis were (a) to determine the sensitivity of resting and post-exercise vagal-related HR variability (HRV) and HR recovery (HRR) indices to detect PNS modulation in F-OR and non-overreached (non-OR) athletes, and (b) to investigate the influence of methodological factors on the sensitivity of HR-based indices to detect PNS hyperactivity in F-OR athletes. We searched CENTRAL, Scopus, PubMed, Embase, and Web of Science up to May 2020 for the following terms: male and female endurance-trained athletes, controlled and uncontrolled studies that carried out an overload training period, and PNS modulation measured in resting and post-exercise, pre- and post-overload training period. A random-effects model of standardized mean difference (SMD) was estimated for each outcome measure based on the training-induced fatigue status (F-OR vs non-OR athletes), and the influence of methodological issues to detect PNS hyperactivity in F-OR was assessed by subgroup analyses. Pooled analysis showed that resting vagal-related HRV indices did not detect PNS hyperactivity in F-OR athletes (SMD+ = -0.01; 95% confidence interval [CI] = -0.51, 0.50), and no statistical difference (P = .600) was found with non-OR athletes (SMD+ = 0.15; 95% CI = -0.14, 0.45). However, subgroup analysis based on HRV parameter showed a moderate statistical increase in weekly averaged HRV in F-OR athletes (SMD+ = 0.81; 95% CI = 0.35, 1.26), while isolated HRV values did not reach statistical significance (SMD+ = -0.45; 95% CI = -0.96, 0.06). We observed a moderate and statistically significant increase in HRR indices among F-OR athletes (SMD+ = 0.65; 95% CI = 0.44, 0.87), no changes for non-OR athletes (SMD+ = 0.10; 95% CI = -0.15, 0.34), and statistically significant differences between F-OR and non-OR athletes (P < .001). Insufficient data prevented meta-analysis for post-exercise vagal-related HRV indices. Our findings show that when methodological factors are considered, HR-based indices are sensitive to increased PNS modulation in F-OR.

Medical encounters, cardiac arrests and deaths during a 109 km community-based mass-participation cycling event: a 3-year study in 102 251 race starters-SAFER IX.

BACKGROUND: There are few data on medical encounters, including deaths during mass-participation cycling events. OBJECTIVE: To determine the incidence and nature of medical encounters during a community-based mass-participation cycling event. DESIGN: Cross-sectional study across three annual events. SETTING: 2012-2014 Cape Town Cycle Tour (109 km), South Africa. PARTICIPANTS: 102 251 race starters (male=80 354, female=21 897). METHODS: Medical encounters (moderate, serious life-threatening, sudden cardiac arrest/death), using the 2019 international consensus definitions, were recorded on race day for 3 years as incidence rates (IR per 1000 starters; 95% CI). Overall illness-related (by organ system) or injury-related (by anatomical region) encounters, and severity were recorded. RESULTS: We recorded 539 medical encounters (IR 5.3; 4.8 to 5.7). The IR was 3.2 for injuries (2.9 to 3.6), 2.1 for illnesses (1.0 to 2.4) and 0.5 for serious life-threatening medical encounters (0.4 to 0.7). In the 3-year study, we encountered three cardiac arrests and one death (2.9 and 1.0 per 100 000 starters, respectively). Injury IRs included upper limb (1.9; 1.6 to 2.1), lower limb (1.0; 0.8 to 1.0) and head/neck (0.8; 0.6 to 1.0). Illness IRs included fluid/electrolyte abnormalities (0.6; 0.5 to 0.8) and the cardiovascular system (0.5; 0.4 to 0.6). CONCLUSION: In a 109 km community-based mass-participation cycling event, medical encounters (moderate to severe) occurred in about 1 in 200 cyclists. Injury-related (1/300 cyclists) encounters were higher than illness-related medical encounters (1 in about 500). Serious life-threatening medical encounters occurred in 1/2000 cyclists. These data allow race organisers to anticipate the medical services required and the approximate extent of demand.

Thinking about your running movement makes you less efficient: attentional focus effects on running economy and kinematics.

A number of studies have shown that attentional focus instructions can effect running economy. This study assessed spiroergometry, as well as running kinematics as a possible mechanism to explain these effects. Twelve runners had to focus their attention on either their running movement, their breathing or on a video while running on a treadmill at a set, submaximum speed. Spiroergometry and running kinematics were measured. Results revealed worse running economy in both internal focus conditions (breathing and movement) compared to the external focus condition (video), replicating previous findings. In addition, vertical oscillation during the running movement was elevated in the movement compared to the video condition, indicating a less efficient running style. No changes in kinematics were found for the breathing compared to the video condition. Therefore, consciously focusing on the running movement moves runners away from their optimised running pattern and leads to detriments in economy. The decreases in running economy in the breathing condition can be better explained by changes in breathing patterns.

[Relaxation techniques and behavioural therapy for the treatment of migraine : Guidelines from the German Migraine and Headache Society]. / Entspannungsverfahren und verhaltenstherapeutische Interventionen zur Behandlung der Migräne : Leitlinie der Deutschen Migräne- und Kopfschmerzgesellschaft.

Besides pharmacological and interventional possibilities nonpharmacological options, deriving from behavioural approaches may be helpful in the treatment of migraine. Already consulting a patient reduces frequency of attacks. Relaxation (especially progressive muscle relaxation), endurance sports, and biofeedback as well as cognitive behavioural therapy are effective in treatment of migraine. The combination of these treatment options also with pharmacological treatment increase the positive effects.

Scoliosis in adulthood-a case with untreated early onset scoliosis presenting at the age of 76 years.

[Purpose] Untreated early-onset scoliosis may eventually progress to more than 90° after growth, cause severe health problems, and increase chance of mortality. Therefore, surgical intervention is often indicated prior to the development of a life-threatening deformity. This case report aims to reveal how a 76-year-old male patient with curves exceeding 110° is functioning with minimal difficulty. [Subject and Methods] The patient, who has never had surgical intervention for scoliosis, can perform his everyday activities. His curves were 111° thoracic and 118° lumbar when he presented at the author's office in January 2015. [Results] The patient reported that he rarely needs a physician and participates in endurance sports like jogging. Despite this, the patient recognizes his restrictive ventilation disorder (shortness of breath) when he is inactive. The patient complained of shortness of breath and cosmetic concerns. [Conclusion] The current guidelines indicate that early-onset scoliosis should be operated at a young age; however, this protocol is not supported by high-quality evidence. Notably, patients with curvatures exceeding 100° after puberty may have a reasonable quality of life when they lead an active life with regular participation in endurance sports and physical rehabilitation.

Clinical and Laboratory Responses of Cross-Country Skiing for a 24-H World Record: Case Report.

The physiological consequences of ultra-endurance cross-country skiing in cold conditions are poorly known. We report here clinical, echocardiographic and laboratory findings from a 41-y old male elite skier in a world record trial for 24-h skiing. The athlete completed a total of 406.8 km outdoors with the temperature ranging between -24°C and -5°C during the 24-h period. Post exercise, notable increases from baseline values were observed in myoglobin (50-fold), creatinine kinase (30-fold) and proBNP (6-fold), whereas troponin T or troponin I levels remained unchanged. At baseline, echocardiographic findings showed cardiac hypertrophy and after skiing, a 5% reduction of left-ventricular end-diastolic dimension. Increases in markers of kidney (creatinine) and liver function (alanine aminotransferase), serum uric acid, C-reactive protein and white blood cell counts were also noted. In addition, electrolyte disturbances including hyponatremia, hypophosphatemia and hypocalcaemia were noted during the follow-up. The data indicates that a prolonged period of high-intensity skiing leads to muscle, heart and kidney affection and activation of inflammation even in an experienced elite skier. The observed health effects underscore the need for strict medical surveillance of participants in extreme sports with long duration. Key pointsAn elite athlete was able to ski over 400 km during 24 hours with an outdoor temperature ranging between -5 °C and -24 °C.Several postrace abnormalities occurred in biomarkers of muscle, heart, kidney, liver and inflammation status.Serum troponins, specific markers of myocardial cell damage, remained stable.The report supports careful medical surveillance of participants in extreme sports with long duration.

Morphological characteristics of the patellar tendon in runners, cyclists, triathletes, and physically active individuals.

The objective of the study was to compare measurements of length, thickness, and cross-section area (CSA) of the patellar tendon (PT) among cyclists, runners, triathletes, and physically active individuals (control group). Forty healthy individuals (10 cyclists, 10 runners, 10 triathletes, and 10 physically active individuals) aged between 18 and 45 years (30.3 ± 8.6 years) participated in the study. PT was measured by a B-mode ultrasound system. To measure the length and thickness (in 5, 10, 15, and 20 mm of the PT length) the probe was positioned parallel to the tendon and to measure the CSA the probe was positioned perpendicularly in 25, 50, and 75% of the PT length. PT length data were analyzed using a one-way ANOVA to compare between groups and PT CSA and thickness were analyzed using a two-way ANOVA (group vs. position) to compare the variables among the groups with the post-hoc Tukey test. All statistical analyses were performed considering p < 0.05. We observed a significant difference, where cyclists had smaller PT thickness (regardless of the location measured) compared to the group of triathletes (p = 0.001) and the physically active group (p = 0.043). All other variables (length, thickness, and CSA) and interactions (local and position) were not significant. We concluded that regardless of the position where PT thickness is measured, cyclists have smaller PT thickness compared to triathletes and physically active individuals but similar when compared to runners. And no differences in the length and CSA of the PT between groups.

Correlation properties of heart rate variability for exercise prescription during prolonged running at constant speeds: A randomized cross-over trial.

The study explores the validity of the nonlinear index alpha 1 of detrended fluctuation analysis (DFAa1) of heart rate (HR) variability for exercise prescription in prolonged constant load running bouts of different intensities. 21 trained endurance athletes (9 w and 12 m) performed a ramp test for ventilatory threshold (vVT1 and vVT2) and DFAa1-based (vDFAa1-1 at 0.75 and vDFAa1-2 at 0.5) running speed detection as well as two 20-min running bouts at vDFAa1-1 and vDFAa1-2 (20-vDFAa1-1 and 20-vDFAa1-2), in which HR, oxygen consumption (VO2), respiratory frequency (RF), DFAa1, and blood lactate concentration [La-] were assessed. 20-vDFAa1-2 could not be finished by all participants (finisher group (FG), n = 15 versus exhaustion group (EG), n = 6). Despite similar mean external loads of vDFAa1-1 (10.6 ± 1.9 km/h) and vDFAa1-2 (13.1 ± 2.4 km/h) for all participants compared to vVT1 (10.8 ± 1.7 km/h) and vVT2 (13.2 ± 1.9 km/h), considerable differences were present for 20-vDFAa1-2 in EG (15.2 ± 2.4 km/h). 20-vDFAa1-1 and 20-DFAa1-2 yielded significant differences in FG for HR (76.2 ± 5.7 vs. 86.4 ± 5.9 %HRPEAK), VO2 (62.1 ± 5.0 vs. 77.5 ± 8.6 %VO2PEAK), RF (40.6 ± 11.3 vs. 46.1 ± 9.8 bpm), DFA-a1 (0.86 ± 0.23 vs. 0.60 ± 0.15), and [La-] (1.41 ± 0.45 vs. 3.34 ± 2.24 mmol/L). Regarding alterations during 20-vDFAa1-1, all parameters showed small changes for all participants, while during 20-vDFAa1-2 RF and DFAa1 showed substantial alterations in FG (RF: 15.6% and DFAa1: -12.8%) and more pronounced in EG (RF: 20.1% and DFAa1: -35.9%). DFAa1-based exercise prescription from incremental testing could be useful for most participants in prolonged running bouts, at least in the moderate to heavy intensity domain. In addition, an individually different increased risk of overloading may occur in the heavy to severe exercise domains and should be further elucidated in the light of durability and decoupling assessment.

Sex Differences in Self-Reported Causes, Symptoms, and Recovery Strategies Associated With Underperformance in Endurance Athletes.

PURPOSE: This study investigated sex differences in self-reported causes, symptoms, and recovery strategies associated with underperformance in endurance athletes. METHODS: A total of 82 athletes (40 women) meeting the inclusion criteria (performance level ≥tier 3, used training diaries, and experienced 1 or more periods of underperformance during their career) completed an online questionnaire. The questionnaire encompassed inquiries regarding load monitoring and experiences with underperformance, focusing on causes, symptoms, and recovery strategies. RESULTS: The most frequently reported symptoms associated with underperformance included psychological (31%), physiological (23%), and health-related (12%) symptoms. Notably, female athletes were more likely to report psychological symptoms associated with underperformance (38% vs 25%, P = .01) compared with male athletes. The leading causes of underperformance comprised illness (21%), mental/emotional challenges (20%), training errors (12%), lack of recovery (10%), and nutritional challenges (5%). Female athletes reported nutritional challenges more frequently as the cause of underperformance compared with males (9% vs 1%, P = .01), whereas male athletes more often attributed underperformance to training errors (15% vs 9%, P = .03). Overall, 67% of athletes reported recovering from underperformance, with a tendency for more male than female athletes to recover (76% vs 58%, P = .07). Furthermore, a higher proportion of male than female athletes reported implementing changes in the training process as a recovery strategy (62% vs 35%, P = .02). CONCLUSIONS: This study offers valuable insights into sex differences in experiences with underperformance in endurance athletes. The findings could inform coaches and athletes in both the prevention and treatment of such incidents.

Post-race reactions: The emotional paradox of high performance and anxiety - a conventional content analysis.

BACKGROUND: Studies examining post-race emotional experiences in the context of endurance races among recreational athletes are scarce. The purpose of this study was to describe how recreational athletes experience the time after completing an endurance race. METHODS: In this study, a qualitative study design was used, and data collection was carried out with semi-structured interviews. The selection of subjects was completed systematically through criterion selection. The selection criteria were men and women, aged 18 years or older, who had completed an endurance race, and finished, lasting at least 180 min within the past 12 months. The interviews were analyzed using conventional qualitative content analysis. RESULTS: Sixteen recreational endurance athletes who, within six months, had completed an endurance race of running, cycling, cross-country skiing or Ironman, participated and were interviewed. Four overarching themes emerged from the analysis: "High on life", "Loss of energy, Ambivalence and Melancholy", "Activity-charged emotions", and "Dimensions of emotions over time and new goals", describing the content of the interviews. CONCLUSIONS: Endurance athletes experienced varied post-race emotions that were both physically and mentally challenging, suggesting a holistic approach to managing post-race emotions would be beneficial. From the athletes' perspectives, post-race feelings were dependent on many factors, including time spent training for a specific race, and perceived inability to set new goals for an upcoming training period. Setting future goals prior to an event may be a tool for reducing the risk of negative post-race emotions, including post-race blues.

The Evolvement of Session Design From Junior Age to Senior Peak Performance in World-Class Cross-Country Skiers.

PURPOSE: To compare designs of training sessions applied by world-class cross-country skiers during their most successful junior and senior season. METHODS: Retrospective analysis of self-reported training characteristics (ie, training form, intensity, and exercise mode) among 8 male and 7 female world-class cross-country skiers was conducted. RESULTS: Total number of sessions (441 [71] vs 519 [34], P < .001, large effect) and mean duration (1.5 [0.1] h vs 1.7 [0.1] h, P < .001, moderate effect) increased from junior to senior age. More double-session days were performed at senior age (124 [50] vs 197 [29] d, P < .001, large). The number (310 [64] vs 393 [64], P < .001, large effect) and duration (1.3 [0.1] h vs 1.5 [0.1] h, P < .001, moderate effect) of low-intensity training sessions increased from junior to senior age. Regarding intensive training, most emphasis was put on high-intensity training sessions lasting 20 to 39 minutes with <5-minute intervals at junior age, while 40 to 59 minutes of moderate-intensity training with 5- to 9-minute intervals was predominant at senior age. More MIXED (combined moderate- and high-intensity) sessions (9 [7] vs 14 [7], P = .023, moderate effect) and longer races (0.5 [0.1] h vs 0.6 [0.1] h, P = 0.29, moderate effect) compensated for fewer high-intensity training sessions at senior age (36 [17] vs 25 [10], P = .027, moderate effect). Duration of strength-training sessions increased significantly (0.6 [0.1] vs 0.8 [0.2] h, P = 0.30, moderate effect), while other training forms remained unchanged. CONCLUSIONS: World-class cross-country skiers increased their training volume from junior to senior age primarily by more and longer low-intensity training sessions and more often training twice per day. Concurrently, the most frequent intensive sessions were modified from high- to moderate-intensity training, lasted longer, and contained longer intervals.

Acute respiratory infections hamper training and competition in cross-country skiers, especially in those with asthma.

Acute respiratory infections (ARinf) are one of the leading causes that prevent athletes from training and competing. The aim of this study was to investigate the burden of ARinfs during one season among cross-country skiers. All Finnish cross-country skiers enrolled in the largest national competitions in winter 2019 (n = 1282) were sent a postal questionnaire. A higher proportion of skiers with than without asthma had to refrain from competitions because of ARinf (76.9% vs. 62.2%, p = 0.011) but there was no significant difference in refraining from training (91.2% vs. 83.8%, p = 0.084). In skiers with asthma, the median duration of a single ARinf episode was longer (5.0 days, IQR 3.8-6.8 vs. 4.0 days, IQR 3.0-6.7, p = 0.017), and they had more days of absence because of ARinf throughout the season (median 15 days (IQR 8-28) vs. 10 days (IQR 6-18), p = 0.006) in comparison to non-asthmatics. However, many of the skiers either trained (54.4%) or competed (22.5%) during an ARinf.

Development of an Instrument to Evaluate the Intake of Liquids, Food and Supplements in Endurance Competitions: Nutritional Intake Questionnaire for Endurance Competitions-NIQEC.

BACKGROUND: In the last few years endurance sports have experienced a great increase in the number of competitions and participants. Dietary-nutritional planning is key for performing well during such competitions. To date, there is no questionnaire expressly developed to be able to analyze the consumption of liquids, foods, and supplements, as well as gastrointestinal problems in these events. This study describes the development of the Nutritional Intake Questionnaire for Endurance Competitions (NIQEC). METHODS: The study was composed in the following phases: (1) Bibliographic search for the most important nutrients, (2) focus groups (17 dietitian-nutritionists and 15 experienced athletes) and generation of items, (3) Delphi surveys, and (4) cognitive interviews. RESULTS: After an initial shaping of the questionnaire with the items that emerged in the focus groups, their relevance was evaluated by means of the Delphi survey, which showed more than 80% approval for most items. Finally, the cognitive interviews indicated that the questionnaire was simple and complete for its purpose. The final NIQEC (n = 50 items) was divided in 5 sections: Demographic data; sports data; consumption of liquids, food and supplements before, during, and after the competition; gastrointestinal complaints, and dietary-nutritional planning for the competition. CONCLUSIONS: The NICEQ is a useful tool that allows collecting information from participants on sociodemographic factors and gastrointestinal complaints, and estimating the intake of liquid, food, and supplements, for endurance competitions.

Does Lactate-Guided Threshold Interval Training within a High-Volume Low-Intensity Approach Represent the "Next Step" in the Evolution of Distance Running Training?

The aim of the present study was to describe a novel training model based on lactate-guided threshold interval training (LGTIT) within a high-volume, low-intensity approach, which characterizes the training pattern in some world-class middle- and long-distance runners and to review the potential physiological mechanisms explaining its effectiveness. This training model consists of performing three to four LGTIT sessions and one VO2max intensity session weekly. In addition, low intensity running is performed up to an overall volume of 150-180 km/week. During LGTIT sessions, the training pace is dictated by a blood lactate concentration target (i.e., internal rather than external training load), typically ranging from 2 to 4.5 mmol·L-1, measured every one to three repetitions. That intensity may allow for a more rapid recovery through a lower central and peripheral fatigue between high-intensity sessions compared with that of greater intensities and, therefore, a greater weekly volume of these specific workouts. The interval character of LGTIT allows for the achievement of high absolute training speeds and, thus, maximizing the number of motor units recruited, despite a relatively low metabolic intensity (i.e., threshold zone). This model may increase the mitochondrial proliferation through the optimization of both calcium and adenosine monophosphate activated protein kinase (AMPK) signaling pathways.

From juniors to seniors: changes in training characteristics and aerobic power in 17 world-class cross-country skiers.

Purpose: To compare training characteristics and aerobic power (VO2max) between the most successful junior and senior seasons of world-class cross-country (XC) skiers and to identify differences between sexes and among sprint and distance skiers. Methods: Retrospective analysis was conducted on self-reported training and VO2max tests of ten male and seven female world-class XC-skiers, collectively holding 38 Olympic medals. Training was categorized by form (endurance, strength, speed, other) and mode (specific, unspecific) and was divided into low- (LIT), moderate- (MIT), and high-intensity training (HIT). Results: Total training increased by 203 ± 130 h (35% ± 31%, p < .001, large effect) and 78 ± 69 sessions (21% ± 24%, p < .001, very large effect). Junior training volume (658 ± 107 h) did not correlate with senior volume (861 ± 74 h) but correlated negatively with changes in volume (r = -.822, p < .001). No sex differences were observed related to total volume, but distance skiers increased their total volume more than sprint skiers (p = .037, large effect). Endurance training increased by 197 ± 117 h (p < .001; large effect) tied to increased low-intensity training (186 ± 115 h, p < .001; large effect) and moderate-intensity training (13 ± 7 h, p < .001; large effect). Training intensity distribution (% LIT/MIT/HIT) was 91/3/6 in junior and 92/4/4 in senior season. Women demonstrated greater increase of unspecific modes (100 ± 58 vs. 37 ± 44 h, p = .022; large effect) and strength training (25 ± 23 vs. -3 ± 17 h, p = .010, large effect). Men improved absolute (8% ± 5%; p = .009; large effect) and relative VO2max (6% ± 4%; p = .016; large effect) from junior to senior, while women only increased relative VO2max (7% ± 5%, p = .012; large effect). Conclusion: This study provides novel information regarding changes in training characteristics and aerobic power from junior to senior age in world-class XC-skiers. Overall, the enhanced training volume during this transition was primarily driven by increased LIT and MIT and the exceptionally high relative VO2max at junior age further increased in both sexes.

Free-living competitive racewalkers and runners with energy availability estimates of <35 kcal·kg fat-free mass-1·day-1 exhibit peak serum progesterone concentrations indicative of ovulatory disturbances: a pilot study.

Introduction: The release of luteinising hormone (LH) before ovulation is disrupted during a state of low energy availability (EA). However, it remains unknown whether a threshold EA exists in athletic populations to trigger ovulatory disturbances (anovulation and luteal phase deficiency) as indicated by peak/mid-luteal serum progesterone concentration (Pk-PRG) during the menstrual cycle. Methods: We assessed EA and Pk-PRG in 15 menstrual cycles to investigate the relationship between EA and Pk-PRG in free-living, competitive (trained-elite) Guatemalan racewalkers (n = 8) and runners (n = 7) [aged: 20 (14-41) years; post-menarche: 5 (2-26) years; height: 1.53 ± 0.09 m; mass: 49 ± 6 kg (41 ± 5 kg fat-free mass "FFM")]. EA was estimated over 7 consecutive days within the follicular phase using food, training, and physical activity diaries. A fasted blood sample was collected during the Pk-PRG period, 6-8 days after the LH peak, but before the final 2 days of each cycle. Serum progesterone concentration was quantified using electrochemiluminescence immunoassay. Results: Participants that reported an EA of <35 kcal·kg FFM-1·day-1 (n = 7) exhibited ovulatory disturbances (Pk-PRG ≤9.40 ng·mL-1). Athletes with EA ≥36 kcal·kg FFM-1·day-1 (n = 8) recorded "normal"/"potentially fertile" cycles (Pk-PRG >9.40 ng·mL-1), except for a single racewalker with the lowest reported protein intake (1.1 g·kg body mass-1·day-1). EA was positively associated with Pk-PRG [r(9) = 0.79, 95% confidence interval (CI): 0.37-0.94; p = 0.003; 1 - ß = 0.99] after excluding participants (n = 4) that likely under-reported/reduced their dietary intake. Conclusions: The result from the linear regression analysis suggests that an EA ≥ 36 kcal·kg FFM-1·day-1 is required to achieve "normal ovulation." The threshold EA associated with ovulatory disturbances in athletes and non-invasive means of monitoring the ovulatory status warrant further research.