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Purpose:

To investigate the effects of an uphill marathon (43 km, 3063-m elevation gain) on running mechanics and neuromuscular fatigue in lower-limb muscles.

Methods:

Maximal mechanical power of lower limbs (MMP), temporal tensiomyographic (TMG) parameters, and muscle-belly displacement (Dm) were determined in the vastus lateralis muscle before and after the competition in 18 runners (age 42.8 ± 9.9 y, body mass 70.1 ± 7.3 kg, maximal oxygen uptake 55.5 ± 7.5 mL · kg−1 · min−1). Contact (tc) and aerial (ta) times, step frequency (f), and running velocity (v) were measured at 3, 14, and 30 km and after the finish line (POST). Peak vertical ground-reaction force (Fmax), vertical displacement of the center of mass (Δz), leg-length change (ΔL), and vertical (kvert) and leg (kleg) stiffness were calculated.

Results:

MMP was inversely related with race time (r = –.56, P = .016), tc (r = –.61, P = .008), and Δz (r = –.57, P = .012) and directly related with Fmax (r = .59, P = .010), ta (r = .48, P = .040), and kvert (r = .51, P = .027). In the fastest subgroup (n = 9) the following parameters were lower in POST (P < .05) than at km 3: ta (–14.1% ± 17.8%), Fmax (–6.2% ± 6.4%), kvert (–17.5% ± 17.2%), and kleg (–11.4% ± 10.9%). The slowest subgroup (n = 9) showed changes (P < .05) at km 30 and POST in Fmax (–5.5% ± 4.9% and –5.3% ± 4.1%), ta (–20.5% ± 16.2% and –21.5% ± 14.4%), tc (5.5% ± 7.5% and 3.2% ± 5.2%), kvert (–14.0% ± 12.8% and –11.8% ± 10.0%), and kleg (–8.9% ± 11.5% and –11.9% ± 12%). TMG temporal parameters decreased in all runners (–27.35% ± 18.0%, P < .001), while Dm increased (24.0% ± 35.0%, P = .005), showing lower-limb stiffness and higher muscle sensibility to the electrical stimulus.

Conclusions:

Greater MMP was related with smaller changes in running mechanics induced by fatigue. Thus, lower-limb power training could improve running performance in uphill marathons.

Giovanelli, Taboga, Rejc, Antonutto, and Lazzer are with the Dept of Biomedical Sciences and Technology, University of Udine, Udine, Italy. Simunic is with the Inst for Kinesiology Research, University of Primorska, Koper, Slovenia.

Address author correspondence to Nicola Giovanelli at nicola.giovanelli@uniud.it.