The randomised, double-blind, crossover study, published in the journalย Nutrientsโ, assessed the effect of supplementing with 5 mg/kg body weight caffeine over one week of training.
The authors from Spain found that the impact of caffeine intake improved the well-being, physical performance and perception of fatigue in the women’s volleyball team athletes.ย
Female-focused research neededย โ
Caffeine is often used in athletic performanceย as an ergogenic aid,โย with its popularity on the rise due to its effect onย aerobicโย andย anaerobic activitiesโ, increasingย strength and power capacityโย byย enhancing intracellular calcium and Na+-K+ ATPase pump activityโย andย delaying the onset of fatigueโย through activation of the central nervous system, whichย blocks the adenosine receptorsโ.
It hasย been well establishedโย that a range of supplementation with a dose of three to nine mg/kg body weight enhances athletic performance.ย And caffeine intake one hour before a training session has been shown to beย an optimal strategy to enhance performanceโย due to its fastย absorption and plasma availabilityโ.ย
The authors noted that whileย previous volleyball studiesโย have reported the effect of caffeine on jumping improvement, components such as agility and change of directionย remain unclearโย and that more evidence is needed to determine the effect of caffeine on agility, especially in womenโs volleyball.
โCaffeine has been proven to deliver positive outcomes inย reducing perceived exertionโย andย diminishing muscular soreness or damageโ, although to aย lesser degree than in menโ,” they wrote.ย โAnd, a main undesirable aspect to consider regarding caffeine supplementation in athletes is that it couldย negatively affect sleep qualityโ, especially in women athletes becauseย the effect of caffeine persists longer in women than in menโ.ย
โThe scientific literature on the ergogenic effect of caffeine on womenโs volleyball players is scarce or lacking, which highlights the importance of this topic in volleyball. Hence, it is important to know its effects on physical performance, fatigue, and wellness.โ
The ‘super league’ studyย โย
The researchers recruited a sample of eight semi-professional womenโs volleyball players from the โSpanish Womenโs Superleague 2โ between the ages of 17 and 25 years and assigned them to either a caffeine or placebo supplementation group. The caffeine group consumed 5 mg/kg of caffeine anhydrous powder based on body weight before acute training.ย Participants switched groups after a one-week washout period.
In both groups, participants performed countermovement jumps, repeated jumps and handgrip tests, and change of direction was assessed.ย Well-being was also evaluated byย wellness questionnaireโ.
Results from ANOVA tests revealed a main effect of supplementation (Fโย (1.7) = 8.41,ย pโย = 0.02, ฮท2 = 0.54) across the training week on physical performance. The researchers also reported a significant effect of caffeine supplementation on perceived muscle damage and fatigue (Fโย (1.7) = 7.29,ย pโย = 0.03, and ฮท2 = 0.51), as well as better handgrip results in the caffeine group as compared to placebo but only in the dominant hand.
โFurther similar research is needed in women that collects both physical performance and well-being parameters and correlates these variables, particularly in highly competitive periods such as the playoffs,โ the researchers concluded.
Source: Nutrientsโ
doi: doi.org/10.3390/nu16010029โ
โThe Effect of Caffeine Supplementation on Female Volleyball Playersโ Performance and Wellness during a Regular Training Weekโโ
Authors: Jesรบs Siquier-Coll et al.