Repeatability of scores on a novel test of endurance running performance

Effects of Specific Bioactive Collagen Peptides in Combination with Concurrent Training on Running Performance and Indicators of Endurance Capacity in Men: A Randomized Controlled Trial

BACKGROUND

First evidence indicates that the supplementation of specific collagen peptides (SCP) is associated with a significant improvement in running performance in physically active women; however, it is unclear if the same is true in males. The purpose of the present study was to investigate the effects of a concurrent training program including 60 min of continuous moderate intensity running training and 15 min of dynamic resistance training combined with supplementation of SCP on parameters of running performance in moderately trained males.

METHODS

In a double-blind, placebo-controlled, randomized trial, participants performed a 12 weeks concurrent training and ingested 15 g of SCP [treatment group (TG)] or placebo [control group (CG)] daily. Before and after the intervention, running endurance performance was measured by a 1-h time trial on a running track. Velocity at the lactate threshold (VLT) and at the individual anaerobic threshold (VIAT) were assessed on a treadmill ergometer. Body composition was evaluated by bioelectrical impedance analysis.

RESULTS

Thirty-two men (28.4 ± 5.2 years) completed the study and were included in the analysis. After 12 weeks, TG had a statistically significant (p ≤ 0.05) higher increase in running distance (1727 ± 705 m) compared to the CG (1018 ± 976 m) in the time trial. VLT increased in the TG by 0.680 ± 1.27 km h-1 and slightly decreased by - 0.135 ± 0.978 km h-1 in the CG, resulting in statistically significant group differences (p ≤ 0.05). A significantly higher improvement in VIAT (p ≤ 0.05) was shown in the TG compared with the CG only (1.660 ± 1.022 km h-1 vs 0.606 ± 0.974 km h-1; p ≤ 0.01). Fat mass decreased (TG - 1.7 ± 1.6 kg; CG - 1.2 ± 2.0 kg) and fat free mass increased (TG 0.2 ± 1.2 kg; CG 0.5 ± 1.3 kg) in both groups with no significant group differences.

CONCLUSION

In summary, supplementation with 15 g of SCP improved running performance in a 1-h time trial and enhanced indicators of endurance capacity at submaximal exercise intensities such as an increased velocity at the lactate as well as the anaerobic threshold more effectively than CT alone.

TRIAL REGISTRATION

ETK: 123/17; DRKS-ID: DRKS00015529 (Registered 07 November 2018-Retrospectively registered); https://drks.de/search/de/trial/DRKS00015529.

A self-paced 15-minute cycling time trial is a reliable performance measure in recreationally active individuals

Cycling time trial (TT) protocols have been shown to be reliable in trained cyclists, but their reproducibility in lesser-trained individuals is unknown. This study examined the reliability of a self-paced 15-minute cycling TT in recreationally active individuals. Twelve recreationally active males (age 27 ± 3 y; body mass 75.2 ± 8.9 kg; V ˙ O2peak = 51.10 ± 7.53 ml∙kg∙min-1) completed a V ˙ O2peak test and four experimental trials, separated by > 48 h. Experimental trials consisted of 10 min cycling at 60% Wmax, followed by a self-paced 15-min TT. Heart rate and work done were recorded every 5 min during the TT; and coefficient of variation (CV) was calculated. Work done was not different (P = 0.706) between trials (193.2 ± 45.3 kJ; 193.2 ± 43.5 kJ; 192.0 ± 42.3 kJ; 193.9 ± 42.8 kJ). Within participant CV ranged from 0.5-4.9% for the four TTs, with a mean CV of 2.1%. Mean CV decreased from 2.0% (range 0.1-5.0%) for the first two TTs to 1.7% (range 0.2-5.6%) for the second and third TTs, and further decreased to 1.0% (range 0.2-1.8%) for the third and fourth TTs. In conclusion, the use of a short-duration self-paced cycling TT in recreationally active individuals is a reliable performance measure.

Influence of Specific Collagen Peptides and Concurrent Training on Cardiometabolic Parameters and Performance Indices in Women: A Randomized Controlled Trial

The purpose was to examine the effects of concurrent training (CT) combined with specific collagen peptides (SCP) intake on cardiometabolic parameters and performance indices in women. In a double-blind, placebo-controlled, randomized trial recreationally active women (n = 59) completed a 12-week CT training (3 day/week) and ingested 15 g of SCP (treatment group [TG]) or placebo (control group [CG]) on a daily basis. Running distance as a marker of endurance performance (time trial), velocity and heart rate at the lactate and anaerobic threshold (incremental running test) and body composition (bioelectrical impedance analysis [BIA]) were measured. BIA measurements included determination of fat mass (FM) and fat free mass (FFM). Additionally, muscular strength (one-repetition-maximum [1RM]) and muscular endurance (60% of 1RM) were assessed. After 12-weeks, TG had a higher increase in running distance (1,034 ± 643 m) compared to the CG (703 ± 356 m) indicated by a significant interaction effect (p < 0.05). Velocity at lactate and anaerobic threshold improved in both groups over time (p < 0.001), with no significant differences between groups. Similarly, heart rate at lactate threshold decreased over time (p < 0.001), with no time × group interaction. TG declined more in heart rate at anaerobic threshold (−8 ± 14 bpm) than the CG (−1 ± 7 bpm), which resulted in a significant interaction effect (p < 0.01). FM decreased over time in TG and CG (p < 0.001), with no group differences. On contrary, TG had a higher increase in FFM (0.8 ± 0.9 kg) compared to the CG (0.3 ± 1.0 kg) (time × group interaction: p < 0.05). Both, 1RM and muscular endurance improved over time (p < 0.001), with no significant group differences. In conclusion, supplementation of SCP in combination with CT resulted in a significant increase in endurance performance compared to the control group. This might potentially be a consequence of improved structural and cardiometabolic adaptations.

Five-Kilometer Time Trial Reliability of a Nonmotorized Treadmill and Comparison of Physiological and Perceptual Responses vs. a Motorized Treadmill

Waldman, HS, Heatherly, AJ, Waddell, AF, Krings, BM, and O'Neal, EK. Five-kilometer time trial reliability of a nonmotorized treadmill and comparison of physiological and perceptual responses vs. a motorized treadmill. J Strength Cond Res 32(5): 1455-1461, 2018-This study examined the reliability of running performance across 3 nonmotorized treadmill (NMT) 5-km time trials (TTs) and physiological, gait, and perceptual differences at a 5-km pace for both NMT and motorized treadmills (MTs). Ten male runners experienced in road racing who had never run on an NMT completed 3 TT to establish personal best 5-km pace. In a later session, participants ran at this pace for 5 minutes on the NMT while metabolic, gait, and perceptual measures were recorded and then ran at outdoor 5-km personal best pace on an MT at 1% grade (counter-balanced crossover design). Intraclass correlation (ICC = 0.95) between the TT1 and TT2 was strong but improved between TT2 and TT3 (ICC = 0.99) with considerable reduction in variability. Nonmotorized treadmill resulted in a 24% slower pace (10.6 ± 1.5 vs. 13.9 ± 2.6 km·h; p < 0.001), shorter stride length (1.02 ± 0.10 vs. 1.27 ± 0.18 m; p < 0.001), and decreased cadence (175 ± 12 vs. 181 ± 13 steps per·minute; p = 0.01). However, V[Combining Dot Above]O2, respiratory exchange ratio (RER), lactate concentration, and heart rate did not differ between modalities (NMT = 3.4 ± 0.4 L·min, 0.96 ± 0.04, 6.9 ± 3.7 mmol, 172 ± 10 b·min; MT = 3.4 ± 0.5 L·min, 0.96 ± 0.04, 5.7 ± 3.4 mmol, 170 ± 10 b·min). rate of perceived exertion (RPE) for legs, breathing, and overall did not differ between treadmill types. A familiarization session should be included for TT using NMT. Other than gait and pace characteristics similar responses were elicited by both treadmills when running at 5-km pace. However, with these considerations, NMT TT of 4-km might be more appropriate in matching MT 5-km TT duration without altering physiological responses significantly.

The Reliability and Validity of a Four-Minute Running Time-Trial in Assessing [Formula: see text]max and Performance

Introduction: Traditional graded-exercise tests to volitional exhaustion (GXTs) are limited by the need to establish starting workloads, stage durations, and step increments. Short-duration time-trials (TTs) may be easier to implement and more ecologically valid in terms of real-world athletic events. The purpose of the current study was to assess the reliability and validity of maximal oxygen uptake (V˙O2max) and performance measured during a traditional GXT (STEP) and a four-minute running time-trial (RunTT).

Methods: Ten recreational runners (age: 32 ± 7 years; body mass: 69 ± 10 kg) completed five STEP tests with a verification phase (VER) and five self-paced RunTTs on a treadmill. The order of the STEP/VER and RunTT trials was alternated and counter-balanced. Performance was measured as time to exhaustion (TTE) for STEP and VER and distance covered for RunTT.

Results: The coefficient of variation (CV) for V˙O2max was similar between STEP, VER, and RunTT (1.9 ± 1.0, 2.2 ± 1.1, and 1.8 ± 0.8%, respectively), but varied for performance between the three types of test (4.5 ± 1.9, 9.7 ± 3.5, and 1.8 ± 0.7% for STEP, VER, and RunTT, respectively). Bland-Altman limits of agreement (bias ± 95%) showed V˙O2max to be 1.6 ± 3.6 mL·kg⁻¹·min⁻¹ higher for STEP vs. RunTT. Peak HR was also significantly higher during STEP compared with RunTT (P = 0.019).

Conclusion: A four-minute running time-trial appears to provide more reliable performance data in comparison to an incremental test to exhaustion, but may underestimate V˙O2max.

VO2max Measured with a Self-selected Work Rate Protocol on an Automated Treadmill

PURPOSE

The use of graded maximal exercise tests for measuring maximal oxygen consumption (VO2max) is common practice in both cardiopulmonary rehabilitation settings and in sports medicine research. Recent alterations of common testing protocols to allow for self-selected work rates (SPV) have elicited V˙O2max values similar to or higher than more traditional style protocols (TP). Research is lacking in the delivery of the SPV protocol using a treadmill modality. The purpose of the study was to examine the validity of an SPV using an automated treadmill for measuring cardiorespiratory fitness.

METHODS

Thirteen experienced endurance runners completed three maximal exercise tests on a treadmill. Oxygen consumption was measured using a computerized system and averaged more than 30-s time periods. SPV was completed using an automated treadmill that consisted of a sonar range finder, microcontroller, and customized computer software. Subject deviations from the middle of the treadmill belt resulted in rapid, graded increases or decreases in speed. TP was completed on the same treadmill without the use of the automated software. A verification phase protocol (VP) was used to verify if VO2 was maximal.

RESULTS

Peak work rate achieved during SPV was significantly greater than that achieved during TP by 1.2 METs; P < 0.05, d = 0.564. Oxygen consumption was significantly greater in TP (64.9 ± 8.2 mL·kg·min) than SPV (63.4 ± 7.8 mL·kg·min); P < 0.005, d = 0.195.

CONCLUSION

An automated treadmill allowed for the completion of SPV similar to what has been reported for cycling. SPV with an automated treadmill did not provide a higher VO2max than TP despite higher work rates.

Pre-exercise hyperhydration-induced bodyweight gain does not alter prolonged treadmill running time-trial performance in warm ambient conditions

This study compared the effect of pre-exercise hyperhydration (PEH) and pre-exercise euhydration (PEE) upon treadmill running time-trial (TT) performance in the heat. Six highly trained runners or triathletes underwent two 18 km TT runs (~28 °C, 25%–30% RH) on a motorized treadmill, in a randomized, crossover fashion, while being euhydrated or after hyperhydration with 26 mL/kg bodyweight (BW) of a 130 mmol/L sodium solution. Subjects then ran four successive 4.5 km blocks alternating between 2.5 km at 1% and 2 km at 6% gradient, while drinking a total of 7 mL/kg BW of a 6% sports drink solution (Gatorade, USA). PEH increased BW by 1.00 ± 0.34 kg (P < 0.01) and, compared with PEE, reduced BW loss from 3.1% ± 0.3% (EUH) to 1.4% ± 0.4% (HYP) (P < 0.01) during exercise. Running TT time did not differ between groups (PEH: 85.6 ± 11.6 min; PEE: 85.3 ± 9.6 min, P = 0.82). Heart rate (5 ± 1 beats/min) and rectal (0.3 ± 0.1 °C) and body (0.2 ± 0.1 °C) temperatures of PEE were higher than those of PEH (P < 0.05). There was no significant difference in abdominal discomfort and perceived exertion or heat stress between groups. Our results suggest that pre-exercise sodium-induced hyperhydration of a magnitude of 1 L does not alter 80–90 min running TT performance under warm conditions in highly-trained runners drinking ~500 mL sports drink during exercise.

Effect of mouth-rinsing carbohydrate solutions on endurance performance

Ingesting carbohydrate-electrolyte solutions during exercise has been reported to benefit self-paced time-trial performance. The mechanism responsible for this ergogenic effect is unclear. For example, during short duration (≤1 hour), intense (>70% maximal oxygen consumption) exercise, euglycaemia is rarely challenged and adequate muscle glycogen remains at the cessation of exercise. The absence of a clear metabolic explanation has led authors to speculate that ingesting carbohydrate solutions during exercise may have a 'non-metabolic' or 'central effect' on endurance performance. This hypothesis has been explored by studies investigating the performance responses of subjects when carbohydrate solutions are mouth rinsed during exercise. The solution is expectorated before ingestion, thus removing the provision of carbohydrate to the peripheral circulation. Studies using this method have reported that simply having carbohydrate in the mouth is associated with improvements in endurance performance. However, the performance response appears to be dependent upon the pre-exercise nutritional status of the subject. Furthermore, the ability to identify a central effect of a carbohydrate mouth rinse maybe affected by the protocol used to assess its impact on performance. Studies using functional MRI and transcranial stimulation have provided evidence that carbohydrate in the mouth stimulates reward centres in the brain and increases corticomotor excitability, respectively. However, further research is needed to determine whether the central effects of mouth-rinsing carbohydrates, which have been seen at rest and during fatiguing exercise, are responsible for improved endurance performance.

Influence of ingesting a carbohydrate-electrolyte solution before and during a 1-hour run in fed endurance-trained runners

The aim of this study was to determine whether the ingestion of a carbohydrate-electrolyte solution would improve 1-h running performance in runners who had consumed a meal 3 h before exercise. Ten endurance-trained male runners completed two trials that required them to run as far as possible in 1 h on an automated treadmill that allowed changes in running speed without manual input. Following the consumption of the pre-exercise meal, which provided 2.5 g carbohydrate per kilogram body mass (BM), runners ingested either a 6.4% carbohydrate-electrolyte solution or placebo solution (i.e. 8 ml x kg BM(-1)) 30 min before and 2 ml x kg BM(-1) at 15-min intervals throughout the 1-h run. There were no differences in total distance covered (placebo: 13,680 m, s = 1525; carbohydrate: 13,589 m, s = 1635) (P > 0.05). Blood glucose and lactate concentration, respiratory exchange ratio, and carbohydrate oxidation during exercise were not different between trials (P > 0.05). There were also no differences in ratings of perceived exertion, felt arousal or pleasure-displeasure between trials (P > 0.05). In conclusion, the ingestion of a 6.4% carbohydrate-electrolyte solution did not improve 1-h running performance when a high carbohydrate meal was consumed 3 h before exercise.

Physiological correlates of 2-mile run performance as determined using a novel on-demand treadmill

The purpose of this study was to assess the reproducibility of an on-demand motorised treadmill to measure 2-mile (3.2 km) race performance and to examine the physiological variables that best predict this free-running performance in active men. Twelve men (mean (SD): age, 28 (9) years; stature, 1.79 (0.05) m; body mass, 72 (9) kg) completed the study in which maximum oxygen uptake (VO2 max), running economy, and running speedin the abstract section. They appear in the rest of the paper.), running economy, and running speed at VO2 max (vVO2 max), lactate threshold (vLT), and 4 mmol.L-1 fixed blood lactate concentration (v4) were measured. Subsequently, the maximal lactate steady state (MLSS) was identified using a series of 30-min treadmill runs. Finally, each participant completed a 2-mile running performance trial on 2 separate occasions, using an on-demand treadmill that adjusts belt speed according to the participant's position on the moving belt. The average 2-mile run speed was 15.7 (SD, 1.9) km.h-1, with small individual differences between repeat-performance trials (intraclass correlation coefficient = 0.99, 95% CI 0.953 to 0.996; standard error of measurement as coefficient of variation = 1.5%, 95% CI 1.0% to 2.5%). Bivariate regression analyses identified VO2 max, vVO2 max, VO2 (mL.kg-1.min-1) at MLSS, vLT, v4, and velocity at MLSS (vMLSS) as the strongest individual predictor variables (r2 = 0.69 to 0.87; standard error of the estimate = 1.08 to 0.72 km.h-1) for 2-mile running performance. The vLT and vMLSS explained 85% and 87% of the variance in running performance, respectively, suggesting that there is considerable shared variance between these parameters. In conclusion, the on-demand treadmill system provided a reliable measure of distance running performance. Both vLT and vMLSS were strong predictors of 2-mile running performance, with vMLSS explaining marginally more of the variance.