A theory of abstaining from sexual activity postulates that sexual frustration increases aggression since testosterone would still be in the body instead of expelled due to ejaculation.
A “Clinical Journal of Sport Medicine” article by Samanatha McGlone and Ian McShrier, titled Does Sex the Night Before Competition Decrease Performance? and published in 2000, suggests that sex the night before has no effect on performance.
One example the authors cite from three physiological studies involved 14 married males to test their grip strength after at least six days of abstinence. This study suggests that sex had no effect on the men’s strength or endurance in the test. Another similar study tested “grip strength, balance, lateral movement, reaction time, and aerobic power” on 10 fit and married men with the similar results. The last study cited, Effects of sexual intercourse on maximal aerobic power, oxygen pulse, and double product in male sedentary subjects, also produced similar conclusions.
Since this is a physiological study, performance would degrade if the sexual activity lead to complete exhaustion. At most 250 calories are burned an hour during (aggressive) sex according to Dr. Gabe Mirkin. A study of heart rate, rate-pressure product, and oxygen uptake during four sexual activitiesshows that the maximum peak of exercise occurs during orgasm but quickly subsides to baseline levels thereafter.
However, that is not to say these studies are absolute. The authors suggest that the effects of aggression on non-physiological variables such as attitude and motivation should have been measured. In addition, there are a number of factors like time of day, stress, fatigue, frequency and duration of sex, diet, sexual partner, and individual sexual responses that are difficult to control in a study.
The article isn’t conclusive, but it also doesn’t dive into mentality at all. In general, sex doesn’t seem to have any significant physiological effects.
The purpose of this study is to gain understanding of the relationship between ejaculation and serum testosterone level in men. The serum testosterone concentrations of 28 volunteers were investigated daily during abstinence periods after ejaculation for two phases. The authors found that the fluctuations of testosterone levels from the 2nd to 5th day of abstinence were minimal. On the 7th day of abstinence, however, a clear peak of serum testosterone appeared, reaching 145.7% of the baseline ( P < 0.01). No regular fluctuation was observed following continuous abstinence after the peak. Ejaculation is the precondition and beginning of the special periodic serum testosterone level variations, which would not occur without ejaculation. The results showed that ejaculation-caused variations were characterized by a peak on the 7th day of abstinence; and that the effective time of an ejaculation is 7 days minimum. These data are the first to document the phenomenon of the periodic change in serum testosterone level; the correlation between ejaculation and periodic change in the serum testosterone level, and the pattern and characteristics of the periodic change.