Comparison of physiological responses of running on a nonmotorized and conventional motor-propelled treadmill at similar intensities.

This study aimed to test the agreement of the incremental test's physiological responses between tethered running on a nonmotorized treadmill (NMT) to matched relative intensities while running on a conventional motorized treadmill (MT). Using a within-subject crossover design, nine male recreational runners (age = 22 ± 5 years; height = 175 ± 6 cm; weight = 68.0 ± 16.6 kg) underwent two test sessions: one was an incremental intensity protocol on an MT; the other was on an instrumented NMT. Intensity thresholds at [Formula: see text]O2max, respiratory compensation point (iRCP), and lactate threshold (iLT) were registered for analysis, together with [Formula: see text]̇O2, [Formula: see text]̇E, ƒR, and blood lactate concentration ([Lac]). Comparisons were based on hypothesis testing (Student's T-test), effect sizes (Cohen's d), ICC, and Bland Altman analysis. Statistical significance was accepted at p < 0.05. Attained [Formula: see text]O2max (MT = 52.2 ± 7.3 mL·kg-1·min-1 vs NMT = 50.1 ± 8.1 mL·kg-1·min-1) and [Formula: see text]̇O2 at iRCP (MT = 46.3 ± 7.2 mL·kg-1·min-1 vs NMT = 42.8 ± 9.3 mL·kg-1·min-1) were not different between ergometers (p = 0.15 and 0.13, respectively), with significant ICCs (0.84 and 0.70, respectively) and Pearson's correlations (r = 0.87 and 0.76, respectively). The [Lac] at iLT presented poor agreement between conditions. Significant correlations were found (r between 0.72 and 0.83) for relative power values of i[Formula: see text]O2max (6.56 ± 1.28 W·kg-1), iRCP (4.38 ± 1.50 W·kg-1), and iLT (4.15 ± 1.29 W·kg-1) related to their counterpart obtained on MT. Results show that running on an NMT offers a higher glycolytic demand under the same relative internal load as running on an MT but with a similar aerobic response and correlated intensity determination.

Comparison of parameters derived from a three-minute all-out test with classical benchmarks for running exercise.

This study aimed to compare four constructs from the three-minute all-out test (AO3)-end power (EP), the area above EP (WEP), maximum power (Pmax), and attained [Formula: see text]-to those derived from the classical CP model in tethered running. Seventeen male recreational runners underwent two experiments to test for reliability and agreement of AO3 parameters with those obtained from the classical CP model (Wꞌ and CP), a graded exercise test ([Formula: see text]) and a 30-second all-out test (AO30s; Pmax); all performed on a non-motorized treadmill (NMT). Significance levels were set at p<0.05. There were no significant differences between test-retest for Pmax (p = 0.51), WEP (p = 0.39), and EP (p = 0.64), showing generally close to zero bias. Further, retest ICC were high for Pmax and EP (ICC > 0.86) but moderate for WEP (ICC = 0.69). Pmax showed no difference between AO3 and AO30s (p = 0.18; CV% = 9.5%). EP and WEP disagreed largely with their classical critical power model counterparts (p = 0.05; CV%>32.7% and p = 0.23; CV%>39.7%, respectively), showing greater error than their test-retest reliability. [Formula: see text] from AO3 was not different (p = 0.13) and well related (CV% = 8.4; ICC = 0.87) to the incremental test [Formula: see text]. Under the studied conditions, the agreement of EP and WEP to CP and Wꞌ was not strong enough to assure their use interchangeably. Pmax and [Formula: see text] were closer to their criterion parameters.

Computational and Complex Network Modeling for Analysis of Sprinter Athletes' Performance in Track Field Tests.

Sports and exercise today are popular for both amateurs and athletes. However, we continue to seek the best ways to analyze best athlete performances and develop specific tools that may help scientists and people in general to analyze athletic achievement. Standard statistics and cause-and-effect research, when applied in isolation, typically do not answer most scientific questions. The human body is a complex holistic system exchanging data during activities, as has been shown in the emerging field of network physiology. However, the literature lacks studies regarding sports performance, running, exercise, and more specifically, sprinter athletes analyzed mathematically through complex network modeling. Here, we propose complex models to jointly analyze distinct tests and variables from track sprinter athletes in an untargeted manner. Through complex propositions, we have incorporated mathematical and computational modeling to analyze anthropometric, biomechanics, and physiological interactions in running exercise conditions. Exercise testing associated with complex network and mathematical outputs make it possible to identify which responses may be critical during running. The physiological basis, aerobic, and biomechanics variables together may play a crucial role in performance. Coaches, trainers, and runners can focus on improving specific outputs that together help toward individuals' goals. Moreover, our type of analysis can inspire the study and analysis of other complex sport scenarios.

Aerobic Evaluation in Elite Slalom Kayakers Using a Tethered Canoe System: A New Proposal.

BACKGROUND: Among other aspects, aerobic fitness is indispensable for performance in slalom canoe. PURPOSE: To propose the maximal-lactate steady-state (MLSS) and critical-force (CF) tests using a tethered canoe system as new strategies for aerobic evaluation in elite slalom kayakers. In addition, the relationship between the aerobic parameters from these tests and the kayakers' performances was studied. METHODS: Twelve male elite slalom kayakers from the Brazilian national team participated in this study. All tests were conducted using a tethered canoe system to obtain the force records. The CF test was applied on 4 d and analyzed by hyperbolic (CFhyper) and linear (CFlin) mathematical models. The MLSS intensity (MLSSint) was obtained by three 30-min continuous tests. The time of a simulated race was considered the performance index. RESULTS: No difference (P < .05) between CFhyper (65.9 ± 1.6 N) and MLSSint (60.3 ± 2.5 N) was observed; however, CFlin (71.1 ± 1.7 N) was higher than MLSSint. An inverse and significant correlation was obtained between MLSSint and performance (r = -.67, P < .05). CONCLUSION: In summary, MLSS and CF tests on a tethered canoe system may be used for aerobic assessment of elite slalom kayakers. In addition, CFhyper may be used as an alternative low-cost and noninvasive method to estimate MLSSint, which is related with slalom kayakers' performance.