Kettlebell Swings as Muscle Builders? Increases in Cortisol & GH & Decreases in Testosterone Which Position the KB Swing Rather as a HIT Fat Burner Than Muscle Builder

Kettlebell swings - According to the results from the study at hand, probably great to shed body fat. not exactly what you should be doing to gain tons of muscle.

Ok, here is my confession: I hate kettle bell training (probably, because I am a pussy ;-). Now that it's out there and you know my bias, it's about time to take a look at the results of a recent study from the University of North Texas in Denton (Budnar Jr. 2014) that investigated the hitherto unknown hormonal response to kettlebell training among strength and conditioning professionals.

I know, there is no reliable evidence that the GH, testosterone and cortisol response to exercise is a good predictor of the exercise induced muscular adaptations - including muscle and strength gains and fat loss, but there are a few neat associations due to which looking at the study results probably isn't totally useless. 

Based on the previously cited study by West et al. (2009 & 2012), the things we should be looking for are elevations of cortisol and growth hormone, but not those of testosterone, which were not associated with either lean muscle mass or type I / type II fiber cross sectional area (CSA).

As you can see in Figure 1, we could expect increases in muscle fiber size with significant increases in cortisol, and increases in total lean body mass if the amount of GH that's circulating in the blood of the ten healthy male volunteers' n (19–30 years; mean 24 years, 175 cm, 78.7 kg) was significantly increased in response to performing 12 rounds of 30 seconds of kettlebell swings alternated with 30 seconds of rest.

The subjects of which the scientists say that they were recreationally trained,  had been engaged in resistance exercise >2 times a week for at least the previous 3 months. They had no history of anabolic steroid use, but more importantly, they had no experience with the kettlebell swing exercise and were thus the perfect candidates for maximal hormonal responses (and strength outcomes) in response to an unaccustomed workout. As Budnar Jr. et al. point out, ...

"[...] Lake and Lauder (2012) have previously demonstrated that training using this exercise protocol improves lower-body strength and power. A 16-kg kettlebell (Perform Better, Cranston, RI, USA) was used by all participants because it is the recommended starting weight for men and has previously been used in evaluating the effect of kettlebell swings on strength training adaptations and acute aerobic responses (Lake. 2012)." (Budnar Jr. 2014) 

Fasted blood samples were collected using intravenous catheter before the warm-up (PRE), immediately postexercise (IP), 15 minutes postexercise (P15), and 30 minutes postexercise (P30) and were analyzed for testosterone (T), growth horomone (GH), cortisol (C), myoglobin, and lactate concentrations.

Table 1: 1.Heart rate (HR) and rating of perceived exertion (RPE; range, 6–20) at rest (HR only) and immediately after each round of kettlebell swings and number of swings per round (Budnar Jr. 2014)

A brief glimpse at the RPE data (rate of perceived exertion; 20 = max) in Table 1 reveals that the workout was pretty exhausting. After only one swing the RPE level had reached 50% of the 20 point maximum. No wonder, considering the fact that the subjects

"[...]completed 12 consecutive rounds of kettlebell swing exercise with each round consisting of 30 seconds of exercise followed by 30 seconds of rest. Investigators provided verbal encouragement to the participant to complete as many swings in the 12-minute period as possible." (Budnar Jr. 2014)

Immediately after the completion of the exercise bout, the participant was seated and the IP blood sample was obtained. The participant remained seated comfortably for the remainder of the session, including during the collection of the P15 and P30 blood samples.

Figure 1: Human growth hormone, cortisol and testosterone response to <15 min of kettlebell swings (Budnar Jr. 2014)

Figure 1 shows the results of the blood samples. The first thing you should notice are the huge differences in cortisol and GH response with one "hyper-responder" who probably went hypo right after his first swing (low glucose ➲ high coritsol + high GH during workouts). 

Bottom line: Overall, the increase in growth hormone (GH) and cortisol (C), would suggest that there will be long-term beneficial effects on the total lean body mass and type I & II fiber size, as they were observed by West et al. (2012) in the previously cited study. Plus: The decrease in testosterone, that occurs in all subjects is not exactly what you'd like to see from a muscle builder. Previous studies do after all show that it's increased in response to classic hypertrophy workouts, even if there is no significant association between the T increase and the subsequent muscle gains.

Considering the fact that the kettlebell swing exercise was performed for a relatively short duration (11.5 minutes in total: 6 minutes of exercise and 5.5 minutes of rest), the results are quite impressive and speak in favor of performing kettlebell swings as a high intensity, but not necessarily a muscle building workout. But just as Budnar Jr. et al. (2014) point out, there debate concerning the physiological importance of the acute hormonal response to resistance exercise for long-term strength and hypertrophy adaptations is still ongoing and the connection is rather putative (Phillips. 2012).

Against that background I would rather stick to the tried and proven, if your goal is maximal muscle hypertrophy. Due to the degree of exhaustion and the overall high energy demand, kettlebell swings would yet make an effective and highly time-efficient high intensity addition to a classic resistance training workout |

References: 

• Budnar Jr, Ronald G., et al. "The acute hormonal response to the kettlebell swing exercise." Journal of strength and conditioning research/National Strength & Conditioning Association (2014). 
• Lake, Jason P., and Mike A. Lauder. "Kettlebell swing training improves maximal and explosive strength." The Journal of Strength & Conditioning Research 26.8 (2012): 2228-2233. 
• Phillips, Stuart M. "Strength and hypertrophy with resistance training: chasing a hormonal ghost." European journal of applied physiology 112.5 (2012): 1981-1983. 
• West, Daniel WD, et al. "Resistance exercise-induced increases in putative anabolic hormones do not enhance muscle protein synthesis or intracellular signalling in young men." The Journal of physiology 587.21 (2009): 5239-5247.
• West, Daniel WD, and Stuart M. Phillips. "Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training." European journal of applied physiology 112.7 (2012): 2693-2702.

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THE ATHLETIC BENEFITS OF CAFFEINE

http://www.boxlifemagazine.com/nutrition/the-athletic-benefits-of-caffeine

Caffeine is the most popular drug in the world. It is found in coffee beans, tea leaves, cocoa beans, chocolate and cola nuts, and its use is incredibly widespread. In the U.S. alone, over 100 million Americans consume 400 million cups of coffee per day, equivalent to 146 billion cups of coffee per year, making the United States the leading consumer of coffee in the world. In fact, coffee is the most commonly consumed beverage in the world. Starbucks thanks you.

Because just about everyone is ingesting caffeine in one way or another, and it is so readily available (coffee, tea, energy drinks, etc.) caffeine is no longer on the banned substance list of the International Olympic Committee (it is now listed as a “controlled or restricted substance”). The reason caffeine is so popular is due to its properties, as is it functions as a mild stimulant—more on that later. As such, it helps wake us up and keeps us going when we feel like throwing in the towel. Therefore, it comes as no surprise that athletes are interested in those very same effects as it is applied to their sport. In fact, there are a few companies that are heavily involved in the CrossFit and weightlifting world that have made a business out of selling coffee (such as Caffeine and Kilos and Bulletproof Coffee). So, can caffeine help to enhance your athletic performance?

How does caffeine work?
To understand how caffeine might help you during a WOD, we need to have a quick biology lesson in how the drug works in the first place. Throughout the day, neurons (an electrically excitable cell that processes and transmits information through electrical and chemical signals) are firing in your body, which leads to the build-up of a neurochemical called adenosine. The nervous system uses special receptors to monitor your body’s adenosine levels. As the day wears on, more and more adenosine (a neuromodulator that plays a role in promoting sleep and suppressing arousal) passes through those receptors—and it makes you sleepy. It’s one of the reasons you get tired at night. Caffeine is believed to work by blocking adenosine receptors in the brain and other organs. This reduces the ability of adenosine to bind to the receptors, which would slow down cellular activity, and helps to keep you from getting tired.

But that’s not where coffee’s kick comes from. With the adenosine receptor clogged, neurotransmitters like dopamine and glutamate can get a head start. Adenosine has a calming effect because it slows the activity of nerve cells, whereas caffeine speeds up the activity of cells. Nerve cells that are stimulated by caffeine release the hormone epinephrine (adrenaline), which increases heart rate, blood pressure, and blood flow to muscles, decreases blood flow to the skin and organs, and causes the liver to release glucose.

But the effects of caffeine can only last so long. It takes about four cups of coffee to block half of the brain’s adenosine receptors, so caffeine is quickly removed from the brain. However, continued exposure to caffeine leads to developing a tolerance to it. Tolerance causes the body to become sensitized to adenosine, so withdrawal causes blood pressure to drop, which can result in headaches and other symptoms. Too much caffeine can result in caffeine intoxication, which is characterized by nervousness, excitement, increased urination, insomnia, intestinal complaints, and sometimes hallucinations.

Caffeine and athletic performance
So, caffeine works to reduce fatigue, and increases our heart rate and blood flow to our muscles. It’s no surprise therefore that there have been numerous studies to examine how the effects of caffeine can be tailored to improve an athlete’s performance. Even the U.S. Military has researched the physiological effects of caffeine on hydration and performance, concluding that it “improves cognitive abilities, marksmanship, physical performance and overall vigilance, while preventing fatigue-related injuries and deaths.” From this research the military actually developed a caffeine chewing gum called Stay Alert, with each piece containing 100 milligrams of caffeine, equivalent to a 6-ounce cup of coffee.

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Starting as long ago as 1978, researchers have been publishing caffeine studies. And in study after study, they concluded that caffeine actually does improve performance. But in what ways?

Enhances endurance levels
Glycogen (a type of sugar in the body) is the principal fuel for muscles and exhaustion occurs when it is depleted. A secondary fuel, which is much more abundantly found in the body, is stored fat. As long as there is still glycogen available, working muscles can utilize fat. Caffeine mobilizes fat stores and encourages working muscles to use fat as a fuel. This delays the depletion of muscle glycogen and allows for a prolongation of exercise. The critical time period in glycogen sparing appears to occur during the first 15 minutes of exercise, where caffeine has been shown to decrease glycogen utilization by as much as 50%. Muscle glycogen is therefore preserved for longer, and is available for use as energy during the later stages of exercise, thus increasing endurance levels and delaying the onset of fatigue. In addition, because caffeine promotes the use of stored fat for energy rather than glycogen, you’ll also benefit from increased fat burning.

May lower an athlete’s perceived level of exertion
As I explained above, caffeine acts as a central nervous system stimulant, producing effects—such as increased heart rate and blood pressure—that can make you feel more alert and energetic. Most experts agree that caffeine’s impact on the nervous system changes one’s perceived level of exertion, making your workout seem easier and allowing you to exercise longer before feeling tired. When you also consider that caffeine aids in reducing the onset of fatigue, it’s not hard to see why you may feel that a workout seems easier, or a weight lighter. A 2013 study published in the European Journal of Sport Science examined caffeine’s effect on an athlete’s rating of perceived exertion (RPE). A group of eleven “resistance-trained individuals” took part in this double-blind, randomized cross-over experimental study whereby they ingested a caffeinated or placebo solution 60 minutes before completing a bout of resistance exercises. The results showed that participants completed significantly greater repetitions to failure, irrespective of exercise, in the presence of caffeine, as well as showing far lower levels of RPE and muscle pain perception.

May reduces the effect of delayed onset muscle soreness (DOMS)
Remember how caffeine blocks the body’s receptors for adenosine, which helps us feel more energized? As it turns out, adenosine is also released by the body in response to inflammation, such as the type that occurs in our muscles after a grueling WOD. So if caffeine is acting to block adenosine, then not only are we going to feel more alert, we’re going to feel less sore after a workout, too. A 2013 study published in the Journal of Strength and Conditioning Research appears to support this. Nine “low caffeine consuming males” were blindly given either caffeine or a placebo one hour prior to completing sets of bicep curls. They received caffeine in proportion to their weight, with the average dose around 385mg. That’s about 2.5 cups of coffee. Then they performed a lot of bicep curls, finishing with a one max-effort set. Over the next few days the participants returned to the lab each day and reported their levels of soreness. Starting on day two, the caffeine group reported significantly lower levels of soreness compared to the placebo group. This difference continued each subsequent day, but was most drastic on days two and three. Soreness to the touch was also drastically different. The placebo group experienced significantly more pain when their biceps were touched up to two days after the test. There are of course some caveats to these findings, namely the fact that all the subjects were males (females may respond differently to caffeine), and they were all low caffeine consumers. The results may not be applicable to regular caffeine users, since they may be less sensitive to caffeine’s effect.

Considerations with caffeine
It is important to remember that despite the apparent benefits of using caffeine, it is still a drug and too much of it can actually have a negative impact on your health and performance. Over-consumption of caffeine can lead to insomnia, indigestion, headaches, irregular or fast heartbeat and dehydration.

A moderate caffeine intake is considered to be 250 mg (milligrams) per day. In research studies, the amount of caffeine that enhances performance ranges from 1.5 to 4 mg per pound of bodyweight taken one hour before exercise.

Recommendations for athlete
If you choose to use caffeine, then here are a few tips that may help you maximize the benefits.

1. Ingest caffeine about 3 – 4 hours before the competition. Although blood levels of caffeine peak much sooner, the maximum caffeine effect on fat stores appears to occur several hours after peak blood levels.

2. Consider decreasing or abstaining from caffeine for 3 – 4 days prior to competition. This allows for any tolerance to caffeine to decrease and helps to ensure the maximum effect of the drug. Be careful though, because this may also lead to caffeine withdrawal.

3. Make sure that you have used caffeine extensively under a variety of training conditions and are thoroughly familiar with how your body reacts to this drug. Never try anything new on competition day.