Several anecdotal reports suggest that sex before competition can affect performance. Our objective was to perform a systematic review and meta-analysis to determine whether athletic performance or some physical fitness measure is affected by prior sexual activity. Web of Science (all databases) and Google Scholar were used to identify studies from which adult healthy subjects were included. As all studies were crossover trials, an inverse variance statistical method with random effects was used to minimize the uncertainty of the pooled effect estimate. Bias was assessed via the revised Cochrane Risk of Bias tool (RoB 2) with a "per protocol" analysis. Nine crossover studies (133 subjects, 99% male) were used in this meta-analysis. All those studies did not examine athletic performance per se, but all studies assessed one or more physical fitness parameters. The RoB 2 suggested that overall, there were some concerns with bias. As there was moderate heterogeneity amongst the different outcomes (Tau² = 0.02, Chi-square = 17.2, df = 8, p = 0.03, I² = 54%), a random-effects model was used. The results neither favored abstinence nor sexual activity before a physical fitness test [standardized mean difference = 0.03 (- 0.10 to 0.16), Z = 0.47, p = 0.64, where a negative standardized mean difference favors abstinence, and a positive standardized mean difference favors sexual activity]. The results demonstrate that sexual activity within 30 min to 24 h before exercise does not appear to affect aerobic fitness, musculoskeletal endurance, or strength/power.

In recent years, various studies have attempted to understand human evolution by examining relationships between athletic performance or physical fitness and facial attractiveness. Over a wide range of five homogeneous groups (n = 327), there is an approximate 3% shared variance between facial attractiveness and athletic performance or physical fitness (95% CI = 0.5-8%, p = 0.002). Further, studies relating human performance and attractiveness often have major methodological limitations that limit their generalizability. Thus, despite statistical significance, the association between facial attractiveness and human performance has questionable biological importance. Here, we present a critique of these studies and provide recommendations to improve the quality of future research in this realm.

Objectives

Human blood gas stability data is limited to small sample sizes and questionable statistical techniques. We sought to determine the stability of blood gases under room temperature and slushed iced conditions in patients using survival analyses.

Methods

Whole blood samples from ∼200 patients were stored in plastic syringes and kept at room temperature (22-24 °C) or in slushed ice (0.1-0.2 °C) before analysis. Arterial and venous pO₂ (15-150 mmHg), pCO₂ (16-72 mmHg), pH (6.73-7.52), and the CO-oximetry panel [total hemoglobin (5.4-19.3 g/dL), percentages of oxyhemoglobin (O₂Hb%, 20-99%), carboxyhemoglobin (COHb, 0.1-5.4%) and methemoglobin (MetHb, 0.2-4.6%)], were measured over 5-time points. The Royal College of Pathologists of Australasia's (RCPA's) criteria determined analyte instability. Survival analyses identified storage times at which 5% of the samples for various analytes became unstable.

Results

COHb and MetHb were stable up to 3 h in slushed ice and at room temperature; pCO₂, pH was stable at room temperature for about 60 min and 3 h in slushed ice. Slushed ice shortened the storage time before pO₂ became unstable (from 40 to 20 min), and the instability increased when baseline pO₂ was ≥60 mmHg. The storage time for pO₂, pCO₂, pH, and CO-oximetry, when measured together, were limited by the pO₂.

Conclusions

When assessing pO₂ in plastic syringes, samples kept in slushed ice harm their stability. For simplicity's sake, the data support storage times for blood gas and CO-oximetry panels of up to 40 min at room temperature if following RCPA guidelines.

Introduction

The idea that sexual activity can affect athletic performance has been a matter of conjecture for the past several decades.

Aim

To provide preliminary data on whether sexual activity the evening before several physical exercise performance tests affects performance the next day.

Methods

Eight participants (mean age, 28 ± 5 years) underwent several physical exercise performance tests on 3 different mornings, under 3 conditions: (i) no sexual intercourse the night before the tests (control), (ii) sexual intercourse the night before the tests, and (iii) yoga the night before the tests (randomized, single-blinded).

Main outcome measures

Physical work capacity, lower body muscular power (standing vertical jump), upper body strength (handgrip strength), reaction time, and upper body musculoskeletal endurance (number of push-ups completed).

Results

All participants experienced orgasm through intercourse. The more pleasurable the orgasm, the lower the systolic blood pressure (SBP) on the day after intercourse (Spearman's rho = -0.86; P = .007). For every 2% increase in the total orgasm score, SBP decreased by 1 mmHg. Intercourse lasted 13 minutes; mean heart rate (HR) and caloric expenditure ranged from 88 to 145 beats/minute and from 53 to 190 kcal, respectively. There were no significant differences in the physical working capacity that elicited an HR of 170 beats/minute, number of push-ups completed, vertical jump height, grip strength, or reaction time across the 3 conditions.

Conclusion

Orgasm through sexual activity on the night before physical exercise may reduce SBP; however, we were unable to demonstrate a statistically significant difference in physical exercise performance in any of the 3 conditions. Zavorsky GS, Vouyoukas E, Pfaus JG. Sexual Activity the Night Before Exercise Does Not Affect Various Measures of Physical Exercise Performance. Sex Med 2019;7:235-240.

Background

There are limited data on lactate stability in whole blood. The purpose of this study was to determine whole blood lactate stability at room temperature and in slushed ice conditions.

Methods

An equal number of arterial and venous samples were obtained from 202 subjects hospitalized for various pathophysiological conditions. Whole blood lactate concentration was measured over 5 different times spanning 80-90 min in a blood gas lab at a major hospital center. Samples were stored at room temperature (22-24°C) or in slushed ice conditions (0.1-0.2°C) before analysis.

Results

The mean increase in lactate concentration was 0.001 mmol/L/min in samples on slushed ice over 90 min. However, at room temperature conditions, the mean increase in lactate concentration was 0.008 mmol/L/min regardless of whether the sample was arterial or venous. An increase in whole blood lactate concentration of ≥ 0.4 mmol/L occured after 45 min at room temperature, with 5% of all whole blood specimens demonstrating a meaningful change at ≤ 20 min. The ≥ 0.4 mmol/L change in whole blood lactate is considered significant based on the College of American Pathologists instrument peer-group standards.

Conclusions

Considering that a change in whole blood lactate concentration of ≥ 0.4 mmol/L is unacceptable instrument peer-group variation as defined by the College of American Pathologists, ice is no longer needed to stabilize whole blood lactate specimens when the draw time to analyze time is < 45 min. Samples remain stable even at 90 min when left on ice.

The first aim of this study was to determine the age group at which marathon performance declines in top male and female runners and to compare that to the runners of average ability. Another aim of this of this study was to examine the age-related yearly decline in marathon performance between age group winners and the average marathon finisher. Data from the New York (NYC), Boston, and Chicago marathons from 2001-2016 were analyzed. Age, sex, and location were used in multiple linear regression models to determine the rate of decline in marathon times. Winners of each age group were assessed in 5-year increments from 16 through 74 years old (n = 47 per age group). The fastest times were between 25-34 years old, with overall champion males at 28.3 years old, and overall champion females at 30.8 years old (p = 0.004). At 35 years of age up to 74 years of age, female age group winners had a faster yearly decline in marathon finishing times compared to male age group winners, irrespective of marathon location [women = (min:sec) 2:33 per year, n = 336; men = 2:06 per year, n = 373, p < 0.01]. The median times between each age group only slowed beginning at 50 years old, thereafter the decline was similar between both men and women (women = 2:36, n = 140; men = 2:57, n = 150, p = 0.11). The median times were fastest at Boston and similar between Chicago and NYC. In conclusion, the rate of decline at 35 years old up to 74 years old is roughly linear (adjusted r2 = 0.88, p < 0.001) with female age group winners demonstrating 27 s per year greater decline per year compared to male age group winners.

Background

Data on the stability of whole blood electrolytes is limited to small sample sizes. We sought to determine the stability of whole blood electrolytes under room temperature and slushed iced conditions in human patients at a major hospital center.

Methods

Whole blood samples were obtained from 203 patients hospitalized for various pathophysiological conditions. Electrolyte concentrations of sodium, potassium [K+], ionized calcium, and chloride were measured at 5 different timepoints spanning 3 h. Samples were stored at room temperature (22-24 °C) or under slushed ice conditions (0.1-0.2 °C) before analysis.

Results

Under both conditions, sodium, ionized calcium, and chloride did not show a measurable change up to 109 min compared to baseline; however, the mean increase in [K+] over 138 min of storage in slushed ice was 0.0032 (0.0021 [5th percentile] to 0.0047 [95th percentile]) mmol/L/min (adjusted R2 = 0.62, P < 0.001). Five percent of the specimens demonstrated a ≥0.3 mmol/L change in [K+] from baseline after 67 min of storage in slushed ice. In contrast, 1% of the specimens stored at room temperature showed the same change at the same timepoint.

Conclusions

Whole blood sodium, [K+], ionized calcium, and chloride concentrations remain stable for at least 109 min at room temperature. However, whole blood specimens stored in slushed ice for not more than 67 min exhibit a 5% probability that the [K+] concentration will increase by at least 0.3 mmol/L compared to baseline. The other analytes do not destabilize for up to 178 min of slushed ice storage.