Kinematics of recreational male runners in "super", minimalist and habitual shoes.

We conducted an exploratory analysis to compare running kinematics of 16 male recreational runners wearing Nike Vaporfly 4% (VP4), Saucony Endorphin racing flat (FLAT), and their habitual (OWN) footwear. We also explored potential relationships between kinematic and physiological changes. Runners (age: 33 ± 12 y, V˙ O2peak: 55.2 ± 4.3 ml · kg-1·min-1) attended 3 sessions after completing an V˙ O2peak test in which sagittal plane 3D kinematics at submaximal running speeds (60%, 70% and 80% ʋ V˙ O2peak) were collected alongside economy measures. Kinematics were compared using notched boxplots, and between-shoe kinematic differences were plotted against between-shoe economy differences. Across intensities, VP4 involved longer flight times (6.7 to 10.0 ms) and lower stance hip range of motion (~3°), and greater vertical pelvis displacement than FLAT (~0.4 cm). Peak dorsiflexion angles (~2°), ankle range of motion (1.0° to 3.9°), and plantarflexion velocities (11.3 to 89.0 deg · sec-1) were greatest in FLAT and lowest in VP4. Foot-ground angles were smaller in FLAT (2.5° to 3.6°). Select kinematic variables were moderately related to economy, with higher step frequencies and shorter step lengths in VP4 and FLAT associated with improved economy versus OWN. Footwear changes from OWN altered running kinematics. The most pronounced differences were observed in ankle, spatiotemporal, and foot-ground angle variables.

Metabolic and performance responses of male runners wearing 3 types of footwear: Nike Vaporfly 4%, Saucony Endorphin racing flats, and their own shoes.

PURPOSE: We compared running economy (RE) and 3-km time-trial (TT) variables of runners wearing Nike Vaporfly 4% (VP4), Saucony Endorphin lightweight racing flats (FLAT), and their habitual running (OWN) footwear. METHODS: Eighteen male recreational runners (age = 33.5 ± 11.9 year (mean ± SD), peak oxygen uptake (VO2peak) = 55.8 ± 4.4 mL/kg·min) attended 4 sessions approximately 7 days apart. The first session consisted of a VO2peak test to inform subsequent RE speeds set at 60%, 70%, and 80% of the speed eliciting VO2peak. In subsequent sessions, treadmill RE and 3-km TTs were assessed in the 3 footwear conditions in a randomized, counterbalanced crossover design. RESULTS: Oxygen consumption (mL/kg·min) was less in VP4 (from 4.3% to 4.4%, p ≤ 0.002) and FLAT (from 2.7% to 3.4%, p ≤ 0.092) vs. OWN across intensities, with a non-significant difference between VP4 and FLAT (1.0%-1.7%, p ≥ 0.292). Findings related to energy cost (W/kg) and energetics cost of transport (J/kg·m) were comparable. VP4 3-km TT performance (11:07.6 ± 0:56.6 mm:ss) was enhanced vs. OWN by 16.6 s (2.4%, p = 0.005) and vs. FLAT by 13.0 s (1.8%, p = 0.032). The 3-km times between OWN and FLAT (0.5%, p = 0.747) were similar. Most runners (n = 11, 61%) ran their fastest TT in VP4. CONCLUSION: Overall, VP4 improved laboratory-based RE measures in male recreational runners at relative speeds compared to OWN, but the RE improvements in VP4 were not significant vs. FLAT. More runners exhibited better treadmill TT performances in VP4 (61%) vs. FLAT (22%) and OWN (17%). The variability in RE (-10.3% to 13.3%) and TT (-4.7% to 9.3%) improvements suggests that responses to different types of shoes are individualized and warrant further investigation.

Strongman vs. traditional resistance training effects on muscular function and performance.

Currently, no evidence exists as to the effectiveness of strongman training programs for performance enhancement. This study compared the effects of 7 weeks of strongman resistance training vs. traditional resistance training on body composition, strength, power, and speed measures. Thirty experienced resistance-trained rugby players were randomly assigned to one of the 2 groups; strongman (n = 15; mean ± SD: age, 23.4 ± 5.6 years; body mass, 91.2 ± 14.8 kg; height, 180.1 ± 6.8 cm) or traditional (n = 15; mean ± SD: age, 22.5 ± 3.4 years; body mass, 93.7 ± 12.3 kg; height, 181.3 ± 5.9 cm). The strongman and traditional training programs required the participants to train twice a week and contained exercises that were matched for biomechanical similarity with equal loading. Participants were assessed for body composition, strength, power, speed, and change of direction (COD) performance. Within-group analyses indicated that all performance measures improved with training (0.2-7%) in both the strongman and traditional training groups. No significant between-group differences were observed in functional performance measures after 7 weeks of resistance training. Between-group differences indicated small positive effects in muscle mass and acceleration performance and large improvements in 1 repetition maximum (1RM) bent over row strength associated with strongman compared with traditional training. Small to moderate positive changes in 1RM squat and deadlift strength, horizontal jump, COD turning ability, and sled push performance were associated with traditional compared with strongman training. Practitioners now have the first evidence on the efficacy of a strongman training program, and it would seem that short-term strongman training programs are as effective as traditional resistance training programs in improving aspects of body composition, muscular function, and performance.