ORIGINAL ARTICLE  EXERCISE PHYSIOLOGY AND BIOMECHANICS 

The Journal of Sports Medicine and Physical Fitness 2025 May;65(5):599-605

DOI: 10.23736/S0022-4707.25.16223-3

Copyright © 2025 EDIZIONI MINERVA MEDICA

language: English

Delayed effects of heavy resistance or ballistic priming on sprint and agility in elite U19 football

René B. JØRGENSEN ^{1, 2}, Lars T. PEDERSEN ^{1, 2}, Torben NIELSEN ^{1, 2}, Heidi K. EGEBÆK ^{3, 4}, Rasmus JENSEN ^{1, 5} ✉

¹ Department for Research in Applied Health Science, University College South Denmark, Kolding, Denmark; ² Department of Physiotherapy, University College South Denmark, Esbjerg, Denmark; ³ Research Unit of Exercise Epidemiology, Department of Sport Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark; ⁴ Department of Applied Health Science, University College Lillebaelt, Odense, Denmark; ⁵ Unit of Nutrition and Health, Department of Health, University College South Denmark, Haderslev, Denmark

BACKGROUND: In elite football, optimization of physical performance increases athlete performance. Sprint and change of directional performance can be improved by previously conducting a priming protocol. However, it is unknown if this priming-induced performance enhancement is long-lasting.
METHODS: Eighteen under 19 years old elite football players (mean ± standard deviation [SD] age: 17.8±0.8 years, height: 181±8 cm, body mass: 72±8 kg) with 34±6 months of strength training experience were tested in 30 m sprint and 505 agility without previous exercise (baseline) or 20 hours following a priming protocol consisting of heavy resistance (heavy) or ballistic (ballistic) training. Baseline testing was performed between 3 and 5pm and the effects of priming were tested between 10 and 11 am the day after training. Heavy consisted of 3*2 repetitions of 85% of 1RM in the back squat, and ballistic consisted of 3*5 repetitions of 40% of 1RM in the specialized jump squat.
RESULTS: Compared to baseline, sprint was improved after 10 m with heavy and ballistic by 0.01 and 0.03 s, respectively (P<0.05), whereas only ballistic improved sprint after 5 m (0.03 s, P<0.05). There were no differences after 30 m sprint or in the agility test.
CONCLUSIONS: Acceleration (i.e., 5 m sprint) is improved 20 hours after performing heavy resistance or ballistic priming exercise. Since these priming exercises can be performed on the previous day, coaches should consider incorporating these in their regular training and match plans.

KEY WORDS: Resistance training; Exercise; Athletic performance; Physical conditioning, human; Soccer