Caffeine Can Be Good
For centuries, caffeine has been the stimulant of choice among humans, and for good reason! Evidence suggests that even in Upper Paleolithic times (10,000 years ago), the raw fruit of the coffee plant (Coffea Arabica) was used to brew a beverage with stimulant properties.
Caffeine naturally originates in 63 species of plants as various types of methylated xanthenes, but the most common forms consumed today include coffee beans, tea leaves, cocoa beans, and cola nuts. The compound is readily absorbed after ingestion; serum levels tend to peak in approximately 60 minutes.
Understandably so, endurance athletes are always in search of a boost in energy and performance. More often than not, caffeine is the go-to for athletes. But is caffeine truly an ergogenic aid and is it safe?
According to American College of Sports Medicine, caffeine may be the most widely used stimulant in the world. It can come in many forms such as coffee, nutrition supplements, tea, soft drinks, energy drinks and chocolate.
Caffeine can reach its highest levels in the blood approximately one hour after ingestion. It can have a stimulant effect on the brain as well as affect blood pressure, pulse rate, stomach acid production and fat stores. Many athletes use caffeine as a potential ergogenic aid and performance enhancer.
Caffeine may help mobilize fat stores, enabling the body to use fat as its primary fuel source. By utilizing fat as fuel, this allows the body to spare glycogen, which is an additional fuel source for the body stored in the muscles and liver.
By delaying muscle glycogen depletion, exercise can be prolonged enabling the athlete to go harder, longer, faster and perform more reps before fatigue. Glycogen sparing is most crucial in the first 15 minutes of exercise. This is when caffeine can help significantly decrease glycogen depletion.
Even though caffeine reaches its highest levels in the blood 45 to 60 minutes after ingestion, some research suggest consuming caffeine three or more hours before exercise is most beneficial. The reason is that caffeine may have a maximum effect on fat stores several hours after peak blood levels.
The Journal of the International Society of Sports Nutrition says that caffeine in the amount equivalent to one to three cups of coffee lowers heart rate during sub-maximal exercise, but not at near maximal or maximal exercise.
The effects of caffeine were measured during dynamic leg exercise on a cycle ergometer. According to the Journal of Applied Physiology, no significant differences were noted in terms of heart rate.
Recent work by the ACSM, on well-trained athletes reported that 3-9mg caffeine per kg (kilogram) of body weight one-hour prior to exercise increased running and cycling endurance in the laboratory.
Is It Legal In Competition?
Based on information provided by the IOC (International Olympic Committee), athletes are allowed up to 12 ug (micorgrams) caffeine per milliliter urine before it is considered illegal (15 ug as per the NCAA) or equivalent to about one cup of coffee.
These limits, however, also allow athletes to consume ‘normal’ amounts of caffeine prior to competition. Its positive effects on sport performance and cognitive functioning have been extensively examined in previous research.
As it relates to enhancing sports performance, it is well- documented that consuming caffeine can improve endurance and maximal-intensity exercise, cognitive functioning, concentration, response time, and even carbohydrate absorption.
As it relates to endurance exercise performance, caffeine has been shown to improve endurance capacity. Caffeine seems to reduce the rate of perceived exertion (RPE) for most forms of exercise.
As it relates to maximal-intensity exercise, caffeine use improves work performed near 100% of VO2max for approximately five minutes.
This improvement is believed to be the effect of the compound on neuromuscular pathways that facilitate muscle fiber recruitment, or increase total fiber recruitment, as well as lower RPE.
Personal trainers know that the average client desiring to lose weight or optimize body composition can make just a few nutritional modifications to create a significant impact on total caloric intake. One of these simple changes includes negating excess beverage calories.
For example, replacing three regular sodas each day with a calorie-free beverage or water can provide for an estimated caloric deficit of 2,500 kcals (assuming 120 calories/beverage) over the course of a single week. After a month, this equals a theoretical equivalent of 2.85 pounds.
Considering the impact of this simple (intake) modification it would be prudent of personal trainers to educate their clients on beverages that they should strategically avoid if attempting to lose weight.
The major issue with calorically-dense beverages is that they are usually rich in simple sugar and fat and do not provide the same level of satiation as calorically-equivalent foods. Many beverages serve as a surplus of empty calories with limited nutritional value, which likely explains New York’s efforts at reducing sugary beverage intakes.
As it relates to cognitive functioning, early research demonstrated caffeine added to a carbohydrate-electrolyte beverage consumed before and during exercise greatly improves attention, psycho motor skills and memory measures.
A more recent study examined the effects of consuming 100mg of caffeine and 45g of carbohydrate in an energy bar before and during 2.5 hours of cycling at 60% of VO2max, followed by a time to exhaustion test at 75% of VO2max.
The participants experienced extended times to exhaustion as well as improved concentration, response time, and performance measures while completing complex cognitive tasks during and after the event. These benefits were elevated compared to consuming an energy bar without caffeine or nothing at all.
It is well-established that caffeine is proven to exert physio – logical effects that may improve performance in a variety of physical events, lower RPE during exercise, and increase cognitive functioning, but new research published in Longevity and Lifespan(December, 2012) has demonstrated that caffeine may also positively affect both total lifespan and healthspan.
The research team examined the effects on a primitive type of worm (or nematode) commonly used in studies concerning genetic analysis. They found that caffeine administration positively influenced two known factors associated with longevity among the worms including dietary restriction and reduced insulin signaling.
Two primary theories exist concerning the mechanisms behind insulin’s effects on longevity.
One theory is that insulin programs metabolic parameters that prolong or reduce lifespan. The other is that insulin determines the cell’s ability to endure oxidative stress from respiration, thereby determining the rate of aging.
Caffeine treatment was also found to delay the progression of a nematode model of polyglutamine disease, suggesting that consumption may enhance resistance to proteotoxic stress – essentially an impairment of cell function due to the misfolding, or breakdown, of structural proteins – increasing its relevance in developing treatments for human diseases, such as Huntington’s or Alzheimer’s disease.
The study authors concluded that caffeine consumption is important to consider when developing clinical interventions designed to mimic dietary restriction or modulate insulin/IGF-1-like signaling.
The team noted that future work addressing the relevant targets of caffeine in models of aging and health-span will help to clarify the underlying mechanisms, potentially identifying new molecular targets for disease intervention
Caffeine may also help assist in enhancing recovery after exercise. According to the American Physiological Society, four hours post-exercise, muscle glycogen increased 66 percent by ingesting a carbohydrate drink containing caffeine as compared to the carbohydrate-only drink.
This type of increase in muscle glycogen can help to expedite recovery and it will help to make the next day’s workout that much more productive. The carbohydrate and caffeine drink post-exercise also resulted in higher blood glucose and plasma insulin.
Each individual can respond differently to caffeine but it is important to use caffiene in moderation. Make sure to stay hydrated as caffiene is a directic and could have more side effect if not used properly such as poor sleep quality, gastrointestinal distress, fatigue, headaches, muscle cramping, and anxiety.
Caffeine can also have a diuretic effect by increasing blood flow to the kidneys and inhibiting the re-absorption of sodium and water.