![]() It has been previously shown that amphetamine increases the temperature at which exhaustion occurs at a high ambient temperature, producing a risk of developing exertional heat stroke (Zaretsky et al. 1974) by altering both heat production and heat dissipation. The balance between heat production and heat dissipation is crucial for keeping the temperature of different compartments of the body in a safe range.Īmphetamine is known to affect the thermoregulatory system (Borbely et al. To limit the temperature growth, regulatory heat dissipation mechanisms, for example, vasodilatation and evaporative cooling through saliva spreading in rodents or sweating in humans, are engaged to help remove heat during physical exercise (Young and Dawson 1982 Horowitz et al. During exercise, the temperature of the muscles as well as the core body temperature is elevated as a consequence of increased heat production in the muscles. High body temperature is one of the strongest exhaustion signals (Walters et al., 2000). However, the mechanism by which amphetamine increases the time to exhaustion is unknown. Although amphetamine usage is prohibited during competitions, it may be used in some situations to improve performance by delaying exhaustion (WADA, 2012). It was previously shown that low to moderate doses of amphetamine increase the time until exhaustion in exercising rats (Wyndham et al. In many conditions exhaustion may serve as an important safety mechanism keeping the organism from irreversible damage caused by intense exercise (Noakes 2012). However, this affects the integrity of thermoregulatory system and may result in potentially dangerous overheating of the muscles. Therefore, we conclude that amphetamine may mask or delay fatigue by slowing down exercise‐induced core body temperature growth by increasing heat dissipation. Furthermore, the model predicted that the muscle temperature at the end of the run in the amphetamine‐treated group was significantly higher than in the control group. Modeling revealed that amphetamine administration increases heat dissipation in the core. Using a mathematical model describing temperature dynamics in two compartments (the core and the muscles), we were able to infer what physiological parameters were affected by amphetamine. In contrast, a lower dose of amphetamine (1 mg/kg) had no effect on measured parameters. The administration of amphetamine slowed down the temperature rise (thus decreasing core body temperature) in the beginning of the run without affecting oxygen consumption. Due to a progressively increasing workload, which was matched by oxygen consumption, the control group exhibited a steady increase in the body temperature. Experimental results showed that rats treated with amphetamine (2 mg/kg) were able to run significantly longer than control rats. To explore this, we measured core body temperature and oxygen consumption of control and amphetamine‐trea ted rats running on a treadmill with an incrementally increasing load (both speed and incline). ![]() Considering that body temperature is one of the major determinants of exhaustion during exercise, we investigated the influence of amphetamine on the thermoregulation. Amphetamine requires OS X 10.8 Mountain Lion or higher.Athletes use amphetamines to improve their performance through largely unknown mechanisms. Please note that keeping your Mac laptop awake while the lid is closed is not possible for an app from the Mac App Store. If you do not activate Amphetamine, your Mac will sleep normally, per your energy saver settings. After you launch Amphetamine, you must activate it by clicking on its menu icon. Amphetamine is 100% free (no ads, no in-app purchases). Features: - Keep your Mac (and optionally its display and drives) awake - Choose from numerous activation time presets, or enter your own - Keep your Mac awake while specific apps are running - Schedule activation/deactivation for specific times of the day - Activate/deactivate with a single click in the menu bar - Activate automatically at launch login - Activate when connected to specific WiFi networks - Keep drives (HDDs/SSDs) connected to your Mac awake - Use global hotkeys for activation/deactivation - Receive alerts while Amphetamine is running or when it activates/deactivates - Auto-deactivate when your Mac's battery drops below a set threshold - Auto-activate when you connect your Mac's power adapter - Allow/prevent screen saver - Use your own status icons - Custom notification sounds - AppleScript support Amphetamine supports Retina displays and OS X's dark mode. With Amphetamine, you can effortlessly override your energy saver settings and keep your Mac awake. ![]() ![]() Amphetamine is a little app that lives in your menu bar. ![]()
0 Comments
Leave a Reply. |