2000-m Time Trial Research Articles

Differences and relationship between velocity attained at VO2max and time trial performances in Para athletes with vision impairment and their guides

The aim of this study was to compare the relationship and difference between velocity attained at maximal oxygen consumption (vVO2max) and 1000-m time trials in Para athletes with vision impairment and their guides. This study had seven Para athletes of class T11 (six Paralympic Games medalists and one non-medalist) and seven respective guides who performed an incremental treadmill test and 1000-m time trial on the athletics track. Data normality was checked through the Shapiro-Wilk test, Student t test, and effect size (ES) to compare differences between groups, and the association between vVO2max and time trial mean velocity (vTT) was made through linear regression. No differences were observed ( p = .555, ES: 0.236) in the VO2max of the T11 athletes (49.29 ± 9.25 ml kg−1 min−1) and their respective guides (51.30 ± 8.92 ml kg−1 min−1), as well as in the vVO2max (T11 athlete: 18.14 ± 3.53 km h−1, guide: 19.00 ± 2.52 km h−1, p = .585, ES: 0.218) and vTT (T11 athlete: 17.25 ± 3.57 km h−1, guide: 20.12 ± 2.25 km h−1, p = .100, ES: 0.735). However, the linear regression analysis between vVO2max and vTT revealed a positive and moderate relationship in T11 athletes (R2 = 0.684, p < .01) and a very large guide (R2 = 0.774, p < .01). The speed reserve of the guide in relation to the T11 athlete was 16%. The results of vTT underestimate the vVO2max more in guides than in T11 athletes.

Calculating Load and Intensity Using Muscle Oxygen Saturation Data.

The study aimed to calculate training intensity and load using muscle oxygen saturation (SmO2) during two differentiated physical tasks. 29 university athletes participated in a 40-m Maximal Shuttle Run Test (MST, 10 × 40-m with 30 s recovery between sprints) and a 3000-m time trial run. Distance and time were used to calculate external load (EL). Internal load indicators were calculated based on percentage of maximum heart rate (%HRMAX) and SmO2 variables: muscle oxygen extraction (∇%SmO2) and the cardio-muscle oxygen index (CMOI) was also provided by relating ∇%SmO2 ÷ %HRMAX, and the training load were calculated as the product of speed (m/min × IL) and the efficiency index [Effindex (m/min ÷ IL)]. A student t test was applied based on Bayesian factor analysis. As expected, EL differed in the 40-m MST (331 ± 22.8) vs. 3000-m trials (222 ± 56.8) [BF10 = 6.25e+6; p = <0.001]. Likewise, IL showed higher values in 40-m MST (39.20 ± 15.44) vs. 3000-m (30.51 ± 8.67) in CMOI: [BF10 = 1.70; p = 0.039]. Training load was greater in 40-m MST (85.77 ± 27.40) vs. 3000-m (15.55 ± 6.77) [(m/min × ∇%SmO2): BF10 = 12.5; p = 0.003] and 40-m MST (129.27 ± 49.44) vs. 3000-m (70.63 ± 32.98) [(m/min × CMOI): BF10 = 169.6; p = <0.001]. Also, the Effindex was higher in 40-m MST (10.19 ± 4.17) vs. 3000-m (6.06 ± 2.21) [(m/min × ∇%SmO2): BF10 = 137.03; p = <0.001] and 40-m MST (9.69 ± 4.11) vs. 3000-m (7.55 ± 1.87) [(m/min × CMOI): BF10 = 1.86; p = 0.035]. This study demonstrates calculations of training intensity and load based on SmO2 as an internal load indicator along with speed as an external load indicator during two differentiated exercises.

Determining V̇O2max in competitive swimmers: Comparing the validity and reliability of cycling, arm cranking, ergometer swimming, and tethered swimming

ObjectivesThis study aims to identify the optimal method for determining V̇O2max in competitive swimmers in terms of validity and test–retest reliability. DesignControlled experiment. MethodsTwenty competitive swimmers performed four maximal incremental exercise tests: cycling, arm cranking, ergometer swimming, and tethered swimming. Gas analysis was conducted to estimate V̇O2max. Validity was assessed in terms of the amount of variance of the performance on a 1500-m time trial explained by the estimated V̇O2max . Test–retest reliability was evaluated using the intraclass correlation coefficient (ICC). ResultsV̇O2max obtained from tethered swimming, ergometer swimming, and cycling explained a similar amount of variance of the 1500-m performance (R2 = 0.64, 0.64 and 0.65, respectively). However, ergometer swimming yielded significantly lower V̇O2max estimates (40.54 ± 6.55 ml/kg/min) than tethered swimming (54.40 ± 6.21 ml/kg/min) and cycling (54.39 ± 5.63 ml/kg/min). Arm cranking resulted in both a lower explained variance (R2 = 0.41) and a significantly lower V̇O2max (43.14 ± 7.81 ml/kg/min). Tethered swimming showed good reliability (ICC = 0.81). ConclusionsBicycle and tethered swimming tests demonstrated high validity with comparable V̇O2max estimates, explaining a large proportion of differences in endurance performance. Choosing between these two methods involves a trade-off between a higher practical applicability and reliability of the bicycle test and the more sport-specific nature of the tethered swimming test.

Five-Week, Low-Intensity Blood Flow Restriction Rowing Improves V̇ o2 max in Elite Rowers.

Held, S, Rappelt, L, Rein, R, Deutsch, J-P, Wiedenmann, T, and Donath, L. Five-week, low-intensity, blood flow restriction rowing improves V̇ o2 max in elite rowers. J Strength Cond Res 38(6): e299-e303, 2024-This controlled intervention study examined the effects of low-intensity rowing with blood flow restriction (BFR) on maximal oxygen uptake (V̇ o2 max), peak power output during ramp testing (PPO), and 2000-m time trial performance (P2k). Eleven, highly elite, male rowers (22.1 ± 1.6 years; 92.6 ± 3.8 kg; 1.93 ± 0.04 m; 7.9. ± 2.2 years rowing experience; 20.4 ± 2.0 h·w -1 training volume; 11.9 ± 1.1 session per week) trained 5 weeks without BFR (Base) followed by a 5-week BFR intervention period. BFR of the lower limb was applied through customized elastic wraps. BFR took place 3 times a week (accumulated net pBFR: 60 min·wk -1 ; occlusion per session: 2 times 10 min·session -1 ) and was used exclusively at low intensities (<2 mmol·L -1 ). V̇ o2 max, PPO, and P2k were examined before, between, and after both intervention periods. Bayesian's credible intervals revealed relevantly increased V̇ o2 max +0.30 L·min -1 (95% credible interval: +0.00 to +0.61 L·min -1 ) adaptations through BFR. By contrast, PPO +14 W (-6 to +34 W) and P2k -5 W (-14 to +3 W) were not noticeably affected by the BFR intervention. This study revealed that 15 sessions of BFR application with a cumulative total BFR load of 5 h over a 5-week macrocycle increased V̇ o2 max remarkably. Thus, pBFR might serve as a promising tool to improve aerobic capacity in highly trained elite rowers.

Cranberry supplementation improves physiological markers of performance in trained runners.

Cranberries have the highest polyphenol and antioxidant capacity among fruits and vegetables and may protect against exercise-induced free radical production, consequently improving performance. This study aimed to investigate the effect of polyphenol-rich cranberry extract (CE) on time-trial performance and lactate response following exercise. A total of 14 trained runners were tested at i) baseline, ii) 2 h following an acute CE dose (0.7 g/kg of body mass), and iii) 4 weeks after daily supplement consumption (0.3 g/kg of body mass). At each time point, runners performed a 1500-m race followed by a 400-m race where the live vastus lateralis oxygenation changes were determined by near-infrared spectroscopy and blood lactate was measured at rest and 1 and 3 min after each trial. The Shapiro-Wilk test and repeated-measures analysis of variance were used to establish significance (P &lt;0.05). Cranberry supplementation over 28 d improved aerobic performance during the 1500-m time trial, whereas the acute dose had no effect. More specifically, muscle reoxygenation rates were significantly faster after 28 d compared to baseline (P = 0.04; η² = 0.29), and a trend towards slower deoxygenation rate was observed (P = 0.13; η² = 0.20). Chronic CE consumption also buffered the post-exercise lactate response for the 400-m race (P = 0.01; η² = 0.27), while no effects were seen for the longer race. Our results suggest that cranberry supplementation may have ergogenic effects, as it improves physiological markers of performance during short- and long-distance running.

Competitive Cross-Country Skiers Have Longer Time to Exhaustion Than Recreational Cross-Country Skiers During Intermittent Work Intervals Normalized to Their Maximal Aerobic Power.

To investigate differences in time to exhaustion (TTE), O2 uptake (V˙O2), and accumulated O2 deficit (O2def) between competitive and recreational cross-country (XC) skiers during an intermittent-interval protocol standardized for maximal aerobic power (MAP). Twelve competitive (maximal V˙O2 [V˙O2max]=76.5±3.8 mL·kg-1·min-1) and 10 recreational (V˙O2max=63.5±6.3 mL·kg-1·min-1) male XC skiers participated. All tests were performed on a rollerski treadmill in the V2 ski-skating technique. To quantify MAP and maximal accumulated oxygen deficit(MAOD), the skiers performed a steady-state submaximal test followed by a 1000-m time trial. After a 60-minute break, TTE, V˙O2, and accumulated O2def were measured during an intermittent-interval protocol (40-s work and 20-s recovery), which was individually tailored to 120% and 60% of each subject's MAP. During the 1000-m time trial, the competitive skiers had 21% (95% CI, 12%-30%) shorter finish time and 24% (95% CI, 14%-34%) higher MAP (all P < .01) than the recreational skiers. No difference was observed in relative exercise intensity (average power/MAP; P = .28), MAOD (P = .18), or fractional utilization of V˙O2max. During the intermittent-interval protocol, the competitive skiers had 34% (95% CI, 3%-65%) longer TTE (P = .03) and accumulated 61% (95% CI, 27%-95%) more O2def (P = .001) than the recreational skiers during work phases. Competitive XC skiers have longer TTE and accumulate more O2def than recreational XC skiers during an intermittent-interval protocol at similar intensity relative to MAP. This implies that performance in intermittent endurance sports is related to the ability to repeatedly recharge fractions of MAOD.

Adding heat stress to repeated-sprint training in hypoxia does not enhance performance improvements in canoe/kayak athletes.

The present study investigated the effects of adding heat stress to repeated-sprint training in hypoxia on performance and physiological adaptations in well-trained athletes. Sixteen canoe/kayak sprinters conducted 2weeks of repeated-sprint training consisting of three sets of 5 × 10s sprints with 20s active recovery periods under conditions of either normobaric hypoxia (RSH, FiO2: 14.5%, ambient temperature: 18 ℃, n = 8) or combined heat and normobaric hypoxia (RSHH, FiO2: 14.5%, ambient temperature: 38 ℃, n = 8). Before and after training, the 10 × 10s repeated-sprint ability (RSA) test and 500m time trial were performed on a canoe/kayak ergometer. Peak and average power outputs during the RSA test were significantly improved after training in both RSH (peak power: + 21.5 ± 4.6%, P < 0.001; average power: + 12.5 ± 1.9%, P < 0.001) and RSHH groups (peak power: + 18.8 ± 6.6%, P = 0.005; average power: + 10.9 ± 6.8%, P = 0.030). Indirect variables of skeletal muscle oxygen extraction (deoxygenated hemoglobin) and blood perfusion (total hemoglobin) during the RSA test were significantly increased after training in the RSH group (P = 0.041 and P = 0.034, respectively) but not in the RSHH group. In addition, finish time during the 500m time trial was significantly shortened after the training only in the RSH group (RSH: -3.9 ± 0.8%, P = 0.005; RSHH: -3.1 ± 1.4%, P = 0.078). Adding heat stress to RSH does not enhance performance improvement and may partially mask muscle tissue adaptation.

Effect of Wearing the Elevation Training Mask on Physiological Performance in Elite Kayaking Girls

Background: The elevation training mask 2.0 (ETM) has been introduced as a novel tool to allow for respiratory muscle training and altitude exposure during exercise that can improve performance and hematological markers in elite and well-trained athletes. Objectives: The purpose of the present study was to examine the effect of wearing ETM while performing exercise training on erythropoietin (EPO), vascular endothelial growth factor (VEGF), peak oxygen consumption (VO2max), lactate, and 1000-m kayaking performance in elite Kayaking girls. Methods: Thirty elite Kayaking girls (14 to 18-year-old) were equally and randomly assigned into mask, no mask, and control groups. The mask and no-mask groups completed 8 weeks of repeated sprint training, while the control group performed their routine kayaking training programs. Pre- and post-training tests included EPO, VEGF, VO2max, lactate, and 1000-m kayaking performance. Results: We showed that 1000-m time trial significantly decreased for mask (P &lt; 0.001) and control (P = 0.035) groups, and was significantly lower in mask group than control (P = 0.014) and no mask (P = 0.009) groups. EPO did not show any significant changes for all groups. VEGF was increased significantly for mask (P = 0.04) and no mask (P = 0.014) groups. Lactate was decreased significantly for mask group (P = 0.025). VO2max increased significantly for no mask group (P = 0.021). Conclusions: Performing repeated sprint training while wearing ETM has the potential to enhance performance in Kayak racing.

Lower volume throughout the taper and higher intensity in the last interval session prior to a 1500m time trial improves performance.

Eight highly trained middle-distance runners (1500m personal best 4:01.4± 0:09.2min) completed two 7-day tapers, separated by at least 3 weeks of regular training: (i) prescribed using prediction models from elite middle-distance runners, where continuous running volume was reduced by 30% and interval intensity was equal to 1500m race pace (RP); and (ii) continuous running volume was reduced by 60% and intensity of the final interval session was completed at 110% of 1500m race pace (HI). Performance was assessed using 1500m time trials on an indoor 200m track 1 day before, and 1 day after each taper. Performance time was improved after HI by 5.2± 3.7s (mean± 90% confidence limits, p= 0.03) and by 3.2± 3.8s after RP (p= 0.15). The first and second 300m segments of the 1500m time trial were faster post-taper in RP (p= 0.012 and p= 0.017, respectively) and HI (both p= 0.012). Running faster than race pace late in a low-volume taper is recommended to improve 1500m track performance. A positive pacing strategy is adopted after tapering, although care should be taken to avoid an over-fast start. Novelty: A large reduction in volume during tapering and an increase in final interval session intensity improves running performance. Athletes adopt a negative pacing strategy before tapering and a positive-pacing strategy after tapering.

Continuous Versus Intermittent Running: Acute Performance Decrement and Training Load.

To examine the effect of continuous (CON) and intermittent (INT) running training sessions of different durations and intensities on subsequent performance and calculated training load (TL). Runners (N = 11) performed a 1500-m time trial as a baseline and after completing 4 different running training sessions. The training sessions were performed in a randomized order and were either maximal for 10minutes (10CON and 10INT) or submaximal for 25minutes (25CON and 25INT). An acute performance decrement (APD) was calculated as the percentage change in 1500-m time-trial speed measured after training compared with baseline. The pattern of APD response was compared with that for several TL metrics (bTRIMP, eTRIMP, iTRIMP, running training stress score, and session rating of perceived exertion) for the respective training sessions. Average speed (P < .001, ηp2=.924) was different for each of the initial training sessions, which all resulted in a significant APD. This APD was similar when compared across the sessions except for a greater APD found after 10INT versus 25CON (P = .02). In contrast, most TL metrics were different and showed the opposite response to APD, being higher for CON versus INT and lower for 10- versus 25-minute sessions (P < .001, ηp2>.563). An APD was observed consistently after running training sessions, but it was not consistent with most of the calculated TL metrics. The lack of agreement found between APD and TL suggests that current methods for quantifying TL are flawed when used to compare CON and INT running training sessions of different durations and intensities.

Mean maximal power from an on-water 1000-m time-trial predicts lactate threshold power in well-trained flat-water sprint kayak athletes

ABSTRACT This study utilised on-water graded exercise tests (GXT) to determine the power output (PO) corresponding to the first and second lactate thresholds (LT1PO and LT2PO), subsequently examining their relationship to the mean maximal power (MMP) and race time achieved across three on-water sprint kayak time-trials. Twelve well-trained sprint kayak athletes completed an on-water GXT and a 200-, 500- and 1000-m time-trial utilising novel instrumented paddle technology. Stepwise multiple regression was used to determine whether equations incorporating 200-, 500- and 1000-m MMP data could be used as an alternative method for estimating LT1PO and LT2PO. On-water GXT derived LT1PO and LT2PO were 151 ± 34 and 194 ± 39 W, respectively. For the 200-, 500- and 1000-m time-trials, MMP were 528 ± 143, 358 ± 92 and 287 ± 67 W, respectively. Athletes’ LT1PO and LT2PO had very-large inverse relationships to 200-, 500- and 1000-m time-to-completion (r = −.71 to −.85, P ≤ .010) and very-large, to near-perfect positive relationships to 200-, 500- and 1000-m MMP (r = .81 to .94, P ≤ .001). The equation incorporating 1000-m MMP alone provided the best prediction of LT1PO and LT2PO, explaining 78% and 88% of the variance, and yielding a standard error of estimate (SEE) of 11.3% and 7.1% for these measures, respectively. The results of this study provide further evidence to support the ecological validity of recently developed on-water GXTs graded by PO, since LT1PO and LT2PO were significantly correlated to 200-, 500- and 1000-m performance. Practitioners could also predict LT2PO with reasonable accuracy based solely from a 1000-m time-trial; potentially providing an alternative, non-invasive, competition-specific protocol for threshold determination. Highlights The fact that LT1PO and LT2PO had very-large, to near-perfect positive relationships to 200-, 500- and 1000-m MMP suggests that coaches should consider these relative submaximal aerobic-fitness variables when evaluating the performance of sprint kayak athletes, regardless of their race specialty. While the SEE and 95% limits of agreement (95%LoA) values for the prediction of LT1PO may be too large to be practically meaningful, measures of LT2PO could be predicted with a reasonable level of accuracy based upon 1000-m MMP. The ability to inform athletes' LT2PO from a single 1000-m time-trial is advantageous since it would provide a more feasible, and time-efficient testing protocol within the athletes' training schedule compared to GXTs, potentially allowing coaches and practitioners to monitor changes in LT2PO, and subsequently review individual training zones, more regularly. Given that LT1PO and LT2PO derived from on-water GXTs had very-large, to nearly perfect relationships to 200-, 500- and 1000-m performance, practitioners may prefer to use on-water, rather than laboratory-based GXTs given their greater practical significance and ecological validity.

Heart-Rate Variability Recording Time and Performance in Collegiate Female Rowers.

To assess the agreement of the root mean square of successive R-R interval (RMSSD) values when recorded immediately upon waking to values recorded later in the morning prior to practice, and to determine the associations of the RMSSD recordings with performance outcomes in female rowers. A total of 31 National Collegiate Athletic Association Division I rowers were monitored for 6 consecutive days. Two seated RMSSD measurements were obtained on at least 3 mornings using a smartphone-based photoplethysmography application. Each 1-minute RMSSD measure was recorded following a 1-minute stabilization period. The first (T1) measurement occurred at the athlete's home following waking, while the second (T2) transpired upon arrival at the team's boathouse immediately before practice. From the measures, the RMSSD mean and coefficient of variation were calculated. Two objective performance assessments were conducted on an indoor rowing ergometer on separate days: 2000-m time trial and distance covered in 30minutes. Interteam rank was determined by the coaches, based on subjective and objective performance markers. The RMSSD mean (intraclass correlation coefficient = .82; 95% CI,.63 to .92) and RMSSD coefficient of variation (intraclass correlation coefficient = .75; 95% CI,.48 to .88) were strongly correlated at T1 and T2, P < .001. The RMSSD mean at T1 and T2 was moderately associated with athlete rank (r = -.55 and r = -.46, respectively), 30-minute distance (r = .40 and r = .41, respectively), and 2000m at T1 (r = -.37), P < .05. No significant correlations were observed for the RMSSD coefficient of variation. Ultrashort RMSSD measurements taken immediately upon waking show very strong agreement with those taken later in the morning, at the practice facility. Future research should more thoroughly investigate the relationship between specific performance indices and the RMSSD mean and coefficient of variation for female collegiate rowers.

Hypoxic re-exposure retains hematological but not performance adaptations post-altitude training.

To test the hypothesis that hypoxic re-exposure after return from natural altitude training is beneficial in retaining hematological and performance adaptations. Eighteen mixed martial art fighters completed a 3-weeks natural altitude training camp at 2418m. Afterwards, participants were randomly assigned to a living high-training low (12h/d at a simulated altitude of 2800m) group (LHTL, n = 9) or a living low-training low group (LLTL, n = 9) for a 3-week sea-level training period. At baseline and after return to sea level, hematological [hemoglobin mass (Hbmass) on days 2, 6, 9, 12, 15 and 21] and performance (3000m time trial and maximal oxygen uptake on days 4, 6, 9, 15 and 21) markers were assessed. Mean Hbmass increased from baseline to day 2 (11.7 ± 0.9 vs. 12.4 ± 1.3g/kg; + 6.6 ± 7.5%; P < 0.05). While Hbmass remained elevated above baseline in LHTL (P < 0.001), it returned near baseline levels from day 9 in LLTL. Irrespective of groups, mean V̇O2max was only elevated above baseline at day 2 (+ 4.5 ± 0.8%) and day 9 (+ 3.8 ± 8.0%) (both P < 0.05). Compared to baseline, 3000m running time decreased at day 4 (-3.1 ± 3.3%; P < 0.05) and day 15 (-2.8 ± 2.3%; P < 0.05) only. Despite re-exposure to hypoxia allowing a recovery of the hypoxic stimulus to retain Hbmass gains from previous altitude sojourn, there is no performance advantage of this practice above sea level residence. Our results also give support to empirical observations describing alternance of periods of optimal and attenuated performance upon return to sea level.

Is individual day-to-day variation of arterial stiffness associated with variation of maximal aerobic performance?

BackgroundMaximal aerobic capacity, e.g. maximal oxygen uptake (V̇O2max), is not constant, and it has a time-dependent variation based on the condition of individual. On the other hand, arterial properties play an important role in determining aerobic performance, and lower arterial stiffness is associated with higher cardiorespiratory fitness levels. This study examined whether individual variations in maximal aerobic performance are associated with arterial stiffness.MethodsTwenty-four (mean age, 19.8 ± 0.2 y) and 10 (mean age, 21.2 ± 0.2 y) recreationally active young men and women participated in Experiment 1 (Ex1) and in Experiment 2 (Ex2), respectively. Aerobic performance was assessed using a graded power test (Ex1) or a 1500-m time trial (Ex2). Simultaneously, brachial-ankle pulse wave velocity (baPWV) was measured as an index of arterial stiffness in both Ex1 and Ex2 before the exercise trials. In both experiments, subjects returned for measurement of baPWV and V̇O2max or 1500-m time trial at 1 month after first measurements.ResultsNo significant differences in mean baPWV, V̇O2max or 1500-m run time were seen between first and second visits. Mean baPWV was significantly lower on days when participants showed higher V̇O2max or better 1500-m run time (P = 0.001 each) than on days when participants showed lower V̇O2max or worse 1500-m run time. In addition, a significant relationship was seen between individual changes in baPWV from first to second visits and changes in V̇O2max (P=0.0001) or 1500-m run time (P=0.04).ConclusionThese findings suggest that individual day-to-day variations in maximal aerobic performance are associated with variations in arterial stiffness.

Changes in Urinary Biomarkers of Organ Damage, Inflammation, Oxidative Stress, and Bone Turnover Following a 3000-m Time Trial.

Strenuous exercise induces organ damage, inflammation, and oxidative stress. Currently, to monitor or investigate physiological conditions, blood biomarkers are frequently used. However, blood sampling is perceived to be an invasive method and may induce stress. Therefore, it is necessary to establish a non-invasive assessment method that reflects physiological conditions. In the present study, we aimed to search for useful biomarkers of organ damage, inflammation, oxidative stress, and bone turnover in urine following exercise. Ten male runners participated in this study and performed a 3000-m time trial. We measured biomarkers in urine collected before and immediately after exercise. Renal damage markers such as urea protein, albumin, N-acetyl-β-D-glucosaminidase (NAG), and liver-fatty acid binding protein (L-FABP), and an intestinal damage marker, intestine-fatty acid binding protein (I-FABP), increased following exercise (p < 0.05). However, a muscle damage marker, titin N-terminal fragments, did not change (p > 0.05). Inflammation-related factors (IRFs), such as interleukin (IL)-1β, IL-1 receptor antagonist (IL-1ra), IL-6, complement (C) 5a, myeloperoxidase (MPO), calprotectin, monocyte chemoattractant protein (MCP)-1, and macrophage colony-stimulating factor (M-CSF), increased whereas IRFs such as IL-4 and IL-10 decreased following exercise (p < 0.05). IRFs such as tumor necrosis factor (TNF)-α, IL-2, IL-8, IL-12p40, and interferon (IFN)-γ did not change (p > 0.05). Oxidative stress markers, such as thiobarbituric acid reactive substances (TBARS) and nitrotyrosine, did not change following exercise (p > 0.05) whereas 8-hydroxy-2′-deoxyguanosine (8-OHdG) decreased (p < 0.05). Bone resorption markers, such as cross-linked N-telopeptide of type I collagen (NTX) and deoxypyridinoline (DPD), did not change following exercise (p > 0.05). These results suggest that organ damage markers and IRFs in urine have the potential to act as non-invasive indicators to evaluate the effects of exercise on organ functions.

Effect of Wearing the Elevation Training Mask on Physiological Performance in Elite Kayaking Girls

Background: The elevation training mask 2.0 (ETM) has been introduced as a novel tool to allow for respiratory muscle training and altitude exposure during exercise that can improve performance and hematological markers in elite and well-trained athletes. Objectives: The purpose of the present study was to examine the effect of wearing ETM while performing exercise training on erythropoietin (EPO), vascular endothelial growth factor (VEGF), peak oxygen consumption (VO2max), lactate, and 1000-m kayaking performance in elite Kayaking girls. Methods: Thirty elite Kayaking girls (14 to 18-year-old) were equally and randomly assigned into mask, no mask, and control groups. The mask and no-mask groups completed 8 weeks of repeated sprint training, while the control group performed their routine kayaking training programs. Pre- and post-training tests included EPO, VEGF, VO2max, lactate, and 1000-m kayaking performance. Results: We showed that 1000-m time trial significantly decreased for mask (P &lt; 0.001) and control (P = 0.035) groups, and was significantly lower in mask group than control (P = 0.014) and no mask (P = 0.009) groups. EPO did not show any significant changes for all groups. VEGF was increased significantly for mask (P = 0.04) and no mask (P = 0.014) groups. Lactate was decreased significantly for mask group (P = 0.025). VO2max increased significantly for no mask group (P = 0.021). Conclusions: Performing repeated sprint training while wearing ETM has the potential to enhance performance in Kayak racing.

Determinants of last lap speed in paced and maximal 1500-m time trials.

The present study identified the physiological and performance characteristics that are deterministic during a maximal 1500-m time trial and in paced 1500-m time trials, with an all-out last lap. Thirty-two trained middle-distance runners (n = 21 male, VO2peak: 72.1 ± 3.2; n = 11, female, VO2peak: 61.2 ± 3.7mL kg-1 min-1) completed a 1500-m time trial in the fastest time possible (1500FAST) as well as a 1500MOD and 1500SLOW trial whereby mean speed was reduced during the 0-1100m by 5% and 10%, respectively. Anaerobic speed reserve (ASR), running economy (RE), the velocity corresponding with VO2peak (VVO2peak), maximal sprint speed (MSS) and maximal accumulated oxygen deficit (MAOD) were determined during additional testing. Carnosine content was quantified by proton magnetic resonance spectroscopy in the gastrocnemius and expressed as a Z-score to estimate muscle fibre typology. 1500FAST time was best explained by RE and VVO2peak in female runners (adjusted r2 = 0.80, P < 0.001), in addition to the 0-1100-m speed relative to VVO2peak in male runners (adjusted r2 = 0.72, P < 0.001). Runners with a higher gastrocnemius carnosine Z-score (i.e., higher estimated percentage of type II fibres) and greater MAOD, reduced their last lap time to a greater extent in the paced 1500-m trials. Neither ASR nor MSS was associated with last lap time in the paced trials. These findings suggest that VVO2 peak and RE are key determinants of 1500-m running performance with a sustained pace from the start, while a higher carnosine Z-score and MAOD are more important for last lap speed in tactical 1500-m races.

High-Intensity Interval Training in Middle-Distance NCAA Division I 800/1500m Collegiate Athletes

Background: High-intensity interval training (HIIT) has grown in popularity, with studies demonstrating improvements in aerobic and anaerobic performances within Sedentary and Recreationally active adults. Little research has been comprised on collegiate, middle-distance runners (800m/1500m). Objective: This research study aimed to investigate the impact of four-weeks HIIT cycling training on collegiate 800/1500m runners performance, and determine whether HIIT can be used as an alternative training method for student athletes. Methods: Twelve middle-distance runners were recruited, with six athletes completing the intervention. Athletes completed pre-testing, which included a 1500m time trial, a GXT, stride length and frequency measurements, and MVIC, using Biopac electromyography (EMG). After pre-testing, athletes completed four weeks of HIIT twice per week. The HIIT consisted of four 20-second bouts with 4 minutes recovery. Following the completion of the training intervention, post-testing was performed for all measures. A paired t-test was used to determine differences between pre- and post-performance tests. An ANOVA was used to determine changes in heart rate and RPE during the GXT. Results: Significant changes were demonstrated between the pre- and post-muscle activation tests of the quadriceps (p=0.05). Significant changes were seen with both HR (p&lt;0.05) and RPE (p&lt;0.05) throughout the GXT. No other significant differences were demonstrated between pre- and post-performance tests, concluding four-weeks HIIT does not alter 800/1500m performance. Conclusion: From the results of this study, HIIT could be used as an alternate method for training for 800/1500m runners. Further reasearch should be conducted toto further understand the impacts of HIIT on middle distance athletes.

Effects of Preferred and Nonpreferred Warm-Up Music on Exercise Performance.

This study investigated the effects of preferred and non-preferred warm-up music listening conditions on subsequent exercise performance. A total of 12 physically active male and female participants engaged in a crossover, counterbalanced research design in which they completed exercise trials after 3 different warm-up experiences of (a) no music (NM), (b) preferred music (PREF), and (c) nonpreferred music (NON-PREF). Participants began warming up by rowing at 50% of of age-predicted heart rate maximum (HRmax) for 5 minutes while exposed to the three music conditions. Immediately following the warm-up and cessation of any music, participants completed a 2000-m rowing time trial as fast as possible. Relative power output, trial time, heart rate, rating of perceived exertion, and motivation were analyzed. Results indicated that, compared with NM, relative power output was significantly higher (p = .018), trial time was significantly lower (p = .044), and heart rate was significantly higher (p = .032) during the PREF but not the NON-PREF condition. Rating of perceived exertion was not altered, regardless of music condition (p > .05). Motivation to exercise was higher during the PREF condition versus the NM (p = .001) and NON-PREF (p < .001) conditions. Listening to preferred warm-up music improved subsequent exercise performance compared with no music, while nonpreferred music did not impart ergogenic benefit.

Improved 2000-m Rowing Performance in a Cool Environment With an External Heating Garment.

Rowers can be in marshaling areas for up to 20 to 25min before the start of a race, which likely negates any benefits of an active warm-up, especially in cold environments. It is unknown if using a heated jacket following a standardized rowing warm-up can improve 2000-m rowing performance. On 2 separate occasions, 10 trained male rowers completed a standardized rowing warm-up, followed by 25min of passive rest before a 2000-m rowing time trial on a rowing ergometer. Throughout the passive rest, the participants wore either a standardized tracksuit top (CON) or an externally heated jacket (HEAT). The trials, presented in a randomized crossover fashion, were performed in a controlled environment (temperature 8°C, humidity 50%). Rowing time-trial performance, core body temperature, and mean skin temperature, along with perceptual variables, were measured. During the 25-min period, core body temperature increased in HEAT and decreased in CON (Δ0.54°C [0.74°C] vs -0.93°C [1.14°C]; P = .02). Additionally, mean skin temperature (30.22°C [1.03°C] vs 28.86°C [1.07°C]) was higher in HEAT versus CON (P < .01). In line with the physiological data, the perceptual data confirmed that participants were more comfortable in HEAT versus CON, and subsequently, rowing performance was improved in HEAT compared with CON (433.1 [12.7]s vs 437.9 [14.4]s, P < .01). The data demonstrate that an upper-body external heating garment worn following a warm-up can improve rowing performance in a cool environment.