According to this study, “greater results of strength and potency are assumed to occur when progesterone is low (in follicular phase, i.e. when menstruation is poured), and especially when estrogen reaches its peak (late follicular phase). And less intense results would occur when progesterone is high (in the luteal or uterine phase).” However, no evidence can be deduced from the research, since five of the studies reviewed by this study affirm that yes, it influences the validity of the ovulatory phase and five others that do not.

This study indicates that the ovulatory cycle can also affect muscle and tendinous rigidity, since estrogen increase can reduce stiffness, as it reduces collagen density in muscles and ligaments. Consequently, in tests requiring short sprints or multiple jumps, the risk of leg injury may be higher or lower at each ovulation stage. However, the results of some studies are also very contradictory on this point: according to some studies it has influence and others it does not.

By increasing progesterone, body thermoregulation (ability to maintain temperature) changes, warming up the body more and can therefore negatively or positively influence performance depending on how long the sport lasts: increasing body temperature improves performance in short-term activities that require speed and power. In contrast, in prolonged activities, the increase in body temperature causes higher thermoregulatory and cardiovascular tension and limits resistance performance. But in this too, research has had a lot of consequences.

The increase in body mass is counterproductive to obtain good results in aerobic resistance. Anaerobic performance also decreases as body mass increases. Some studies that analyzed the body composition of female athletes during the different phases of the ovulatory cycle state that body mass and the amount of body water increased from the follicular phase (menstrual degrowth) to the uterine phase. This may be related to decreased insulin as progesterone increases and fluid retention as aldosterone increases. On the contrary, other studies indicate that the body composition of athletes is not affected by the ovulation phases.

This study, which reviewed 35 studies, says that 15 studies do, that ovulation phases influence yields, and that 20 studies found no evidence that ovulation phases affect performance. On the basis of studies that have concluded that there has been an impact, the study concludes that: “It seems that in the early follicular phase (menstruation days) it is possible to improve the results of aerobic performance, but the strength yield decreases, the resistance decreases in the ovulation phase, while the strength and anaerobic performance improve in this phase.”

Athletes say yes, ovulation phases influence their performance

Between 50-71% of the athletes who have participated in the research indicate that the performance of the training is influenced by the ovulation phase and 49-65% indicate that the performance in competition influences. In some phases of ovulation, they perceive different strength, velocity and potency. Athletes claim that performance is better at all stages of ovulation, except at the stage of menstruation (premature follicular phase) and late uterine phase (nominal late luteus in figure).

The perception of a decrease in performance corresponds to the appearance of menstrual symptoms. And athletes who have noticed a decrease in performance are the ones who most point out that they feel tired or crazy. Some elite athletes have also been harmed by performance: the first days of menstruation divert attention to menstrual pains and worry about preventing them.

Gaps in research

The study has explained that the method used by some studies raises doubts. For example, the three studies that analyzed the influence of the ovulation cycle in sport are based on the memories of the athletes, that is, they were asked to remember the participants in the research. According to the study, “it is possible that not everything is remembered and, therefore, that the participants increase or underestimate the impact of the cycle on the activity”.

Sixteen studies studied only two phases of the ovulation cycle, and ten of these sixteen studies concluded that the cycle does not influence sports performance. The study requires future research: “The most recent recommendation is to evaluate the results in at least three phases, namely the early follicular phase (in which the rule is poured), the ovulatory and the uterine media, as they are the only hormonal means.”

The study also points out that there are no fluidity studies. And we have to investigate whether the ovulation phases affect lightness, as this would impact the performance of jumping and running sports.

It also highlights that some sports have been studied very little: the collective sports practiced abroad have been much less researched than the individual ones. The study recognizes that it has not studied the cognitive performance of athletes: “We recognize the importance of cognition in the overall performance of the athlete, especially in collective sports abroad.”

A statistically non-significant difference can bring gold medal in sport

The study warns that some of the studies it has reviewed have concluded that the impact of ovulation phases in sport “is not significant”, and that these differences may not be statistically significant, but are so “significant” for elite sport that they can lead to victory or failure. “For example, in one study, it was not statistically significant that in swimming tests of 100 meters of free style swimmers swam 2.3 quick seconds in the late uterus phase, but in the menstrual phase. It should be borne in mind, from this data, that the ovulation phase greatly influences swimming performance, as there was a difference of 1.95 seconds between swimmers who practiced first and eighth at a 100-meter free end at the 1992 Olympic Games.” This study therefore requires that sports research take into account the parameters of sports performance when analysing the findings.

The need to investigate multiple bodies

The study points out that it is important to keep in mind that the ovulation cycle affects each body differently: remember that among those who have menstruation there are bodies that undergo important changes in the ovulatory phases and that affect them much less.

It also includes the need for body tests that notice and do not notice premenstrual symptoms “to determine whether PMS induces athletes to make greater changes in their performance.”

The study highlights the need to investigate separately the bodies that adopt hormonal contraceptives, in which hormonal events are different.

And it also specifies that bodies that do not have a “eumenorrheoic” ovulation cycle (covering cycles of 21 to 35 days) should be investigated: “A comprehensive review would be needed to properly analyze complexities.”