Researchers at Beijing Sport University and other institutions in China and the UK investigated how the individual and combined supplements influenced repeated aerial duel performance and neck neuromuscular function in male collegiate soccer players over a 4-week period.
The results showed that caffeine was more closely linked to initiation-related output, whereas Rhodiola was associated with maintenance-related responses under repeated loading.
“The novelty of the present study lies in applying this differentiated supplementation framework to a soccer-specific repeated aerial duel model integrating take-off kinetics, repeated heading performance, neck neuromuscular function, and contest outcomes,” the researchers wrote in the journal Nutrients
Mechanisms at play
The demands of aerial dueling performance require both rapid initiation and the ability to maintain performance across repeated efforts.
The ergogenic effects of caffeine are mainly due to its antagonism of adenosine receptors, which increases alertness and reduces perceived exertion during exercise.
“As a classic adenosine receptor antagonist, CAF [caffeine] is thought to enhance rapid force production primarily by attenuating central inhibition, increasing neural drive, and improving the recruitment efficiency of high-threshold motor units during movement initiation,” the current study noted.
Caffeine also preserves muscle glycogen and increases calcium ion release, enhancing muscle contraction power.
In contrast, Rhodiola rosea acts as an adaptogen, with antioxidant, anti-fatigue, and stress-regulating properties, “and may therefore be more likely to attenuate fatigue accumulation during repeated high-intensity loading and help maintain performance during exercise,” the researchers wrote.
Consequently, combining the two supplements may support a soccer-specific task such as aerial dueling that requires explosiveness and repeatability.
Study details
The study involved 96 male soccer players from the varsity teams at Beijing Sport University who had been training in soccer for at least 6 years and were in good physical condition, with no neuromuscular or cardiovascular disorders. Participants were only included if they had not consumed regular caffeine or alcohol in the three months prior to the study.
The players were randomly assigned to four groups: Rhodiola rosea (RHO), caffeine (CAF), combined Rhodiola rosea and caffeine (RHO + CAF), or placebo for the four-week study period.
Supplements were administered in capsule form at dosages of 3 mg·kg−1 caffeine, ingested 30 minutes before testing, and 2.4 g RHO, divided into two daily doses, ingested in a fasted state.
The outcome measures included countermovement jump height, early take-off impulse, repeated heading contact height, ball exit velocity, heading duel success rate, neck maximal voluntary isometric contraction, and session rating of perceived exertion (session-RPE).
The researchers found significant effects across many of the parameters, noting that “CAF was mainly associated with improved takeoff-related explosive performance and duel success, whereas RHO was mainly associated with lower perceived exertion and better maintenance of heading contact height during the later repeated trials.”
They wrote that the combined supplementation “produced the broadest pattern of benefits across explosive output, ball-contact performance, duel success, and multidirectional neck strength.”
The researchers noted that their findings provide a theoretical basis for future research focused on neurophysiological mechanisms, biomechanical evidence chains, and optimization of combined supplementation strategies.
Source: Nutrients 2026, 18(9), 1339; https://doi.org/10.3390/nu18091339 “Effects of Combined Caffeine and Rhodiola rosea Supplementation on Repeated Aerial Duel Performance and Neck Neuromuscular Function in Soccer Players.” Authors: Y. Dou et al.
