The synergistic effect of the supplements may provide a “promising nutritional strategy for high-intensity intermittent exercise,” researchers from Wuhan Sports University and Beijing Sport University in China wrote in the journal Metabolites.
“Together, they complement each other by optimizing energy supply and neural drive.”
Rhodiola and caffeine in sports performance
Rhodiola rosea and caffeine have both been studied as ergogenic aids to support exercise performance and recovery.
Rhodiola rosea contains active compounds rosavin and salidroside that have been shown to boost anaerobic capacity in muscle fibers, facilitate mitochondrial biogenesis and accelerate ATP resynthesis, “thereby providing direct energy support for explosive power output,” the researchers noted.
Evidence also suggests that rhodiola stimulates pathways that enhance and optimize oxygen delivery and muscle contraction.
Caffeine is a central nervous system stimulant that antagonizes adenosine receptors, promoting the release of neurotransmitters and catecholamines. Caffeine can increase muscle contraction force, reduce fatigue and optimize performance.
The researchers report that the combined effect of the two supplements has not been studied in boxing, a sport that requires explosive power and sustained output.
“Trained boxing volunteers, whose performance nears physiological limits, exhibit a significant “ceiling effect”, making single interventions or supplements less effective in yielding noticeable improvements,” they noted.
“However, the combined supplementation of CAF and RHO, through synergistic effects, can still extend physiological boundaries, leading to marginal improvements in performance.”
Study details
The study involved 96 participants from Wuhan Sports University, with an equal number of participants with four ears of boxing training and participants with no prior training. While completing two weekly sessions of an eight-week boxing training program, they were randomly assigned to consume a daily dose of 2.4g Rhodiola rosea (RHO), caffeine (CAF) at 3 mg per kg of body weight only on the final test day, a combination of daily RHO and CAF on the test day, or a placebo.
The experimental groups exhibited similar macronutrient patterns with no significant differences. The study also controlled for training intensity and sleep, meaning that the observed improvements in performance can be attributed to the supplementation, the researchers wrote.
The study assessed participant punch performance using professional boxing equipment and biomechanical testing.
Results revealed significant improvements in trained and untrained participants in the CAF + RHO group.
Compared to the RHO group, the combined supplement group showed “higher lead punch velocity, shorter bi-lateral peak force time during rear punches, and more punches in the 30 s test,” the researchers wrote.
Compared to the CAF-only group, the combined group “exhibited greater rear punch force, higher bilateral peak force during lead punches, increased forefoot peak force in rear punches, and improved 30 s power output,” they added.
Concluding that the combined supplement outperformed the single supplements in all parameters, the researchers noted that this may be due to “improved energy metabolism efficiency and neuromuscular coordination”.
They acknowledged the study’s limitations, calling for larger trials that measure biochemical markers to fully explore the specific mechanisms.
Source: Metabolites 2025, 15(4), 262; doi: 10.3390/metabo15040262. “Combined Effects of Rhodiola Rosea and Caffeine Supplementation on Straight Punch Explosive Power in Untrained and Trained Boxing Volunteers: A Synergistic Approach”. Authors: B. Tao et al.