Objective: This study evaluated the effects of advanced footwear technology (AFT) spikes on running performance measures, spatiotemporal variables, and perceptive parameters on different surfaces (track and grass). Methods: Twenty-seven male trained runners were recruited for this study. In Experiment 1, participants performed 12 × 200 m at a self-perceived 3000 m running pace with a recovery of 5 min. Performance (time in each repetition), spatiotemporal, and perceptive parameters were measured. In Experiment 2, participants performed 8 × 5 min at 4.44 m/s while energy cost of running (W/kg), spatiotemporal, and perceptive parameters were measured. In both experiments the surface was randomized and mirror order between spike conditions (Polyether Block Amide (PEBA) and PEBA + Plate) was used. Results: Experiment 1: Runners were faster on the track (p = 0.002) and using PEBA + Plate spike (p = 0.049). Experiment 2: Running on grass increased energy cost (p = 0.03) and heart rate (p < 0.001) regardless of the spike used, while PEBA + Plate spike reduced respiratory exchange ratio (RER) (p = 0.041). Step frequency was different across surfaces (p < 0.001) and spikes (p = 0.002), with increased performance and comfort perceived with PEBA + Plate spikes (p < 0.001; p = 0.049). Conclusions: Running on the track surface with PEBA + Plate spikes enhanced auto-perceived 3000 m running performance, showed lower RER, and improved auto-perceptive comfort and performance. Running on grass surfaces increased energy cost and heart rate without differences between spike conditions.

Objective: This study aimed to analyse the influence of Advanced Footwear Technology (AFT) on biomechanical, muscle damage, metabolic and oxidative stress markers in experienced long-distance runners.Methods: Using a counter-balanced randomized experimental design with twelve tier 3 male runners, two AFTs were tested: Cloudboom Strike (CS) and Cloudboom Echo 3 (CE). All participants completed, in both conditions, a graded exercise test (GXT) to determine the VT₁, followed by a prolonged effort test (60-min) at an intensity 10% above VT₁. Finally a GXT to exhaustion to assess the changes in biomechanical parameters in a fatigued state was performed. 24-h before and after each visit, blood samples were drawn for muscle damage, metabolic and oxidative stress determination.Results: Creatin kinase (CK) increased post-visit in both CS and CE (p = 0.026; ES = 0.69 and p = 0.018; ES = 0.59; respectively). However, no other significant differences pre- and post-visit were found in lactate dehydrogenase (LDH), Interleukin-6 (IL-6), alanine aminotransferase (ALT), cortisol or total antioxidant status (TAS) in either the CS or CE conditions. There were no differences between conditions in any of the biomarkers measured, although participants perceived lower DOMS post-24 h with the CS model (p = 0.016; ES = 0.71). We found no shoe × time interaction in any biomechanical parameter evaluated during the prolonged effort or any variable at any speed stage between footwear conditions in the GXT to exhaustion.Conclusion: According to our results, both the Cloudboom Strike and the Cloudboom Echo 3 models appear to provide minimal biomarker responses under these conditions after a 60-min treadmill run, regards to reducing muscle damage, oxidative and metabolic stress, soreness, and inflammation. This indicates attenuated biomarker responses when compared to previous studies with traditional footwear.

Objective: This study aimed to compare trained male and female athletes regarding physiological, perceptual, and performance variables at ventilatory thresholds (VT₁ and VT₂). Methods: Twenty-four male and nineteen female trained runners (age: 27.9 ± 6.4 vs. 24.4 ± 4.4 years; body mass: 61.8 ± 4.3 vs. 52.6 ± 4.1 kg; height: 174.6 ± 5.8 vs. 165.0 ± 5.0 cm for males and females, respectively) performed a graded exercise test to exhaustion on a treadmill. During the test, oxygen consumption, respiratory exchange ratio, running power output, heart rate, muscle oxygenation, and rate of perceived exertion were analyzed. Sex differences were evaluated with an unpaired-samples t-test. Results: Males exhibited significantly higher respiratory exchange ratios (0.87 ± 0.04 vs. 0.83 ± 0.03; 1.03 ± 0.06 vs. 1.01 ± 0.06) and absolute running speeds (15.00 ± 1.06 vs. 12.42 ± 1.22 km·h⁻¹; 19.04 ± 1.06 vs. 16.32 ± 1.29 km·h⁻¹) at both thresholds (p < 0.05), whereas women showed higher muscle oxygenation in vastus lateralis (60.44 ± 21.21 vs. 26.38 ± 10.21%) and fractional utilization of maximal aerobic speed (93.64 ± 6.44 vs. 91.43 ± 3.21%) at VT₂ (p < 0.01). Also, rate of perceived exertion was similar between sexes at both thresholds. Conclusion: Males showed higher absolute physiological values, while females demonstrated greater fractional utilization at VT₂ and higher muscle oxygenation. No sex differences were observed in rate of perceived exertion. These findings highlight the importance of using ventilatory thresholds in training prescription.

Purpose : This study aimed to evaluate the reliability and reproducibility of running economy measurements across multiple days and within the same day using 2 models of advanced footwear technology. Methods : Thirteen trained male runners (age: 27.6 [8.2] y; body mass: 64.4 [6.1] kg; height: 1.74 [0.06] m) completed 4 treadmill sessions separated by 7 days. Two advanced footwear technology models were tested in a randomized crossover design. Each session included two 5-minute trials per shoe condition at 13 km·h ⁻¹ . Reliability and reproducibility of running economy measures were evaluated using intraclass correlation coefficients (ICCs), SEM, coefficient of variation, and smallest worthwhile change. Results : Intrasession ICCs and coefficient of variations for oxygen cost and metabolic cost were excellent for both shoe conditions (.917 and .945; .921 and .948; ∼1%). Intersession reliability was good (oxygen cost ICC = .819; metabolic cost ICC = .849), though coefficient of variations increased (∼2%). No significant differences in metabolic variables were observed between footwear models ( P ≥ .05), and high variability was observed between individuals. Day-to-day variability affected oxygen cost and metabolic cost ( P < .05), independent of shoe condition. Conclusion : Running economy measurements are highly reliable within sessions but demonstrate moderate variability across days. Despite mechanical differences in footwear conditions, no differences were observed between the 2 models. These findings highlight the importance of multitrial, multiday, and individual testing when evaluating footwear conditions.