Purpose : This study quantified running pace and relative exercise intensity during a HYROX PRO MEN event by integrating laboratory-derived aerobic markers with competition data. Methods : Twenty-four male HYROX PRO MEN athletes (race time: 69:58 [5:05] min:s) completed a maximal incremental treadmill test to determine second ventilatory threshold (VT2), maximal aerobic speed (vVO ₂ max), and maximal oxygen uptake (VO ₂ max). Within 10 days, participants competed in the official HYROX Madrid 2025 event. Running speed was calculated for each of the eight 1-km segments and the Roxzone, as well as for the total running component, defined as the combined distance of run 1 to 8 and the Roxzone (8.70 km), and expressed in absolute terms (kilometers per hour) and relative to VT2 and vVO ₂ max. Results : During laboratory testing, athletes reached a VO ₂ max of 51.56 (5.00) mL·kg ⁻¹ ·min ⁻¹ (95% CI, 49.56 to 53.56), with VT2 and vVO ₂ max occurring at 16.41 (0.87) km·h ⁻¹ (95% CI, 16.06 to 16.76), and 18.08 (0.81) km·h ⁻¹ (95% CI, 17.76 to 18.40), respectively. Competition running speed declined from 16.13 (0.97) km·h ⁻¹ (95% CI, 15.74 to 16.52) in run 1 to 13.58 (1.02) km·h ⁻¹ (95% CI, 13.17 to 13.99) in run 8, with the lowest speed in the Roxzone (10.52 [1.18] km·h ⁻¹ ; 95% CI, 10.05 to 10.99). Mean intensity, calculated across the 8 running segments and the Roxzone, corresponded to 84.13% (5.54%) of VT2 (95% CI, 82.66 to 87.10) and 76.33% (4.05%) of vVO ₂ max (95% CI, 75.31 to 78.55). Conclusions : Running in HYROX PRO MEN is performed at submaximal intensities relative to VT2 and vVO ₂ max and declines progressively across segments. Sustaining a higher relative intensity appears central to shorter total running time.

Background: Steel club training is a form of strength and conditioning exercise that involves swinging weighted clubs through circular and pendular movements, thereby imposing substantial rotational and multiplanar demands on the trunk. However, the core muscle activation patterns elicited by these exercises remain poorly characterized. Purpose: This study aimed to characterize global, muscle-specific, and side-to-side core muscle activation across a battery of steel club exercises and compare it with that of conventional plank variations. Methods: A within-subject experimental design was used in a single-session laboratory setting. Fourteen trained males (n = 14) performed ten steel club exercise conditions (comprising seven distinct movement patterns, with unilateral variations performed bilaterally) using 8 and 16 kg clubs and four isometric plank variations; data from n = 13 were available for the Shield Cast 16 kg condition and the omnibus ANOVA due to one excluded signal. Surface electromyography was bilaterally recorded from the rectus abdominis, external oblique, internal oblique, and multifidus muscles and normalized to maximal voluntary contraction (% MVC). Repeated-measures ANOVA was used to assess global and muscle-specific differences across exercise conditions, and paired-samples t-tests were used to evaluate side-to-side differences. Results: Global core activation significantly differed across exercises (p < 0.001, ηp² = 0.798) and was generally greater during steel club exercises than during conventional planks. The Lateral Pendulum to Shoulder Cast (54.77 ± 9.32% MVC), Gamma Cast (47.79 ± 8.96% MVC), and Shield Cast (43.96 ± 11.25% MVC), all performed with 16 kg, elicited greater global activation than each of the four plank variations (all adjusted p < 0.05). The internal oblique showed the greatest activation across most steel club exercises, reaching 69.40 ± 12.18% MVC during the Lateral Pendulum to Shoulder Cast. Several unilateral exercises also elicited significant side-to-side differences, particularly Mills and Reverse Mills (all p < 0.05). Conclusions: Among experienced steel club practitioners, these exercises elicited exercise-specific, dynamic, and multiplanar core activation patterns, with several exercises—particularly those performed with 16 kg—producing greater global activation than conventional plank variations. These findings support steel club training as a complementary modality for dynamic core training, although the independent contributions of movement pattern and external load, as well as long-term adaptations, remain to be established.