Effect of caffeine ingestion on competitive rifle shooting performance

The Effect of Wet Conditions and Surface Combat Swimming on Shooting

INTRODUCTION

Shooting ability is an important aspect of performance in some sports and is vital during a military operation. Load carriage, clothing, and equipment normally associated with fatigue and reduced field of vision or lack of stability at a specific point are important factors that affect the ability to aim when shooting. Additionally, gun support and equipment appear to differentially affect shooting ability with varying shooting positions. All of the studies examining these factors have taken place on dry land and not in water. However, up to date, no study has examined the effect of wet conditions, especially after surface combat swimming (sCS), on shooting ability in different shooting positions. The purpose of this study was to determine the effect of fatigue, produced by prolonged sCS, on a fighter's shooting ability. In addition, we investigated whether the effect of fatigue and wet conditions differed between the shooting positions.

MATERIALS AND METHODS

Forty-five participants performed 10 shots in a shooting simulator while standing (ST) and 10 shots while kneeling (KN). This was performed twice and in three conditions: dry, wet, and after 1,000 m of sCS.

RESULTS

Wet conditions did not significantly affect shooting abilities. Surface combat swimming negatively affected shooting ability when both ST and KN. The reduction in the center of gravity (COG) of the shots after sCS was 3.7 ± 2.5% for ST and 3.5 ± 0.8% for KN (P < .01). This was accompanied by the increase in horizontal and vertical movement of the gun after the sCS (P < .01). Kneeling was more stable, as shown by a higher percentage of COG of the shots by 3.3 ± 0.1% (P < .01) and by fewer gun movements in both axes (P < .01).

CONCLUSIONS

In conclusion, combat swimming affects shooting ability, both in ST and in KN positions. The KN position provides better stability and improved shooting ability.

Automated Detection of Caffeinated Coffee-Induced Short-Term Effects on ECG Signals Using EMD, DWT, and WPD

The effect of coffee (caffeinated) on electro-cardiac activity is not yet sufficiently researched. In the current study, the occurrence of coffee-induced short-term changes in electrocardiogram (ECG) signals was examined. Further, a machine learning model that can efficiently detect coffee-induced alterations in cardiac activity is proposed. The ECG signals were decomposed using three different joint time-frequency decomposition methods: empirical mode decomposition, discrete wavelet transforms, and wavelet packet decomposition with varying decomposition parameters. Various statistical and entropy-based features were computed from the decomposed coefficients. The statistical significance of these features was computed using Wilcoxon's signed-rank (WSR) test for significance testing. The results of the WSR tests infer a significant change in many of these parameters after the consumption of coffee (caffeinated). Further, the analysis of the frequency bands of the decomposed coefficients reveals that most of the significant change was localized in the lower frequency band (<22.5 Hz). Herein, the performance of nine machine learning models is compared and a gradient-boosted tree classifier is proposed as the best model. The results suggest that the gradient-boosted tree (GBT) model that was developed using a db2 mother wavelet at level 2 decomposition shows the highest mean classification accuracy of 78%. The outcome of the current study will open up new possibilities in detecting the effects of drugs, various food products, and alcohol on cardiac functionality.

The role of death anxiety on marksmanship performance: a virtual reality simulator study

Despite the well-established relationship between state anxiety and marksmanship performance, few efforts have examined the individual differences that affect the extent to which individuals experience state anxiety in combat situations. Thus, further studies are needed to increase the probability of mission accomplishment, which could ultimately serve to safely bring soldiers home. The present study examined how death anxiety, a trait-based difference affects state anxiety, which in turn affects shooting performance on a battlefield. In particular, we used a virtual reality simulator to create a realistic engagement setting in which simulated death anxiety is salient. On a sample of 99 active-duty enlisted men in the Republic of Korea Army, we found that death anxiety, and not trait anxiety, increased state anxiety, which in turn decreased marksmanship performance. Overall, the current findings highlight the role of death anxiety in combat situations. The practical implications and avenues for future research are also discussed.

Effect of caffeine ingestion on free-throw performance in college basketball players

Background

It is currently unclear whether pre-exercise caffeine ingestion can improve free-throw shooting performance, a vital skill in basketball. The purpose of this study was to investigate the effects of caffeine on free-throw shooting performance in college-aged basketball players.

Methods

Twelve males (23.1 ± 1.9 years; 180.1 ± 8.8 cm; 77.1 ± 12.4 kg) and six females (22.0 ± 1.3 years; 169.4 ± 8.9 cm; 67.0 ± 11.1 kg) who competed at the college level ingested 6 mg per kg of body mass of (a) caffeine or (b) maltodextrin (placebo) on two separate occasions in a random order. After 60 min, they performed five sets of a match-simulated basketball protocol comprising six sideline-to-sideline sprints on a standard basketball court followed by two free-throws after each set. The number of successful shots was counted. Heart rate and rating of perceived exertion (RPE) after each sprint set were also recorded.

Results

Caffeine ingestion did not improve overall free-throw success (caffeine = 6.1 ± 1.7 vs. placebo = 5.5 ± 2.0; p = 0.34) compared with placebo across all five sets. There was no change in shooting accuracy across sprint sets in either trial despite significant increases in both heart rate and RPE. Caffeine increased heart rate (p = 0.02) but had no effect on RPE (p = 0.57) across five sets compared with placebo.

Conclusions

Ingestion of 6 mg of caffeine per kg of body mass did not improve basketball free-throw performance. Free-throw performance did not deteriorate with increasing number of sprint sets.