We have all suffered from some form of cramps in our lives, and we all hate them, especially when exercising or competing. I in particular am a great sufferer of these horrible yet interesting phenomena. There are many theories that discuss the reasons behind cramping. I will discuss the most commonly thought perpetrator – the theory that uses low salt or electrolyte levels, and the newer theory, to do with muscular fatigue and certain receptors within the muscle.
The theory that uses the old thought that the loss of electrolytes (for example - sodium, magnesium, potassium, sometimes referred to as salts) through sweating and dehydration in hot weather to be the cause of cramping. However research has shown many times over that in people who cramp, electrolyte and dehydration levels remain relatively the same compared to those who did not cramp or are usual sufferers of cramping. Another problem I have in particular with this theory in relation to my experiences is that I often cramp up when swimming, even in coldish water, when I am not sweating and my body is immersed in cool water, however when I go for a long jog, I usually don’t cramp and while jogging it is hot and I am sweating profusely, so then what could be causing my cramping..?
The other theory I would like to discuss is a muscle fatigue theory. It is to do with increased alpha motor neuron activity. These neurons innervate muscles and are responsible for initiating muscle contraction. These alpha motor neurons increase in activity during exercise resulting in more muscle contraction. Now within muscles and their tendons are two mechanoreceptors (detect mechanical change), a Golgi Tendon Organ (GTO) which detects increased contraction and tension in muscles and relaxes them before they are damaged, and Muscle Spindles which detect over stretching of muscles and contract the muscles when they are over stretched before they get damaged. When these two are in balance everything is fine. During usually long bouts of increased activity, muscle spindle activity increases and GTO activity decreases (more contraction, less relaxation) which result in a muscle cramping.
Another side theory to this muscle fatigue theory is that muscles prone to cramping are often muscles that cross over two joints such as the gastrocnemius (muscle of the calf group) (ankle and knee joints) , yes you know what a calf cramp feels like, the hamstring group (hip and knee joints) and the rectus femoris (hip and knee joints) (part of the quadriceps). Now these are three of the most common cramps experienced in activity. This is thought to be because muscles most often cramp in shortened positions, and a muscle that crosses two joints can be shortened that little extra (if your toes are pointed down – plantar flexion, and your knee is flexed, your gastrocnemius is shortened further that just from pointing your toes down). In a shortened position your GTO has even further decreased ability to relax the muscle and increased contraction can result in a cramp.
The most simple way of relieving these cramps are to passively stretch the muscle out using your hands for example. This increases muscle tension and activates the GTO which then relaxes the muscle again and relieves the cramp.
The mechanisms behind cramping are not set in stone, but theories do exist, some with more merit than others. So next time you cramp up, don’t just jump for your electrolyte drink or your old faithful banana. Maybe think about a nice quiet stretch and some rest, maybe, just maybe it’ll work for you too…!
JJ
Tuesday, February 23, 2010
Monday, February 22, 2010
Creatine: What you should know
Creatine is a compound naturally produced in the liver, kidneys and pancreas from amino acids (simple proteins) and can also be obtained in foods such as meat and fish (especially raw, eg. sushi) and to a lesser extent eggs and soya products. Almost all creatine in the body is stored in skeletal muscle, transported there via the blood, and is used in energy production and muscle contractions.
Creatine is utilised in muscle tissue (in the form of creatine phosphate - CP) to reform the high-energy/energy storing compound ATP, particularly during short-term, high intensity movements and activity. Over time, CP stores in the muscles are used up and one becomes unable to maintain high intensities in, for example, sprinting or lifting weights. Supplementing with creatine therefore helps to delay this fatigue.
It has also been shown to increase strength and body weight gains, as well as improve recovery after workouts/training. Increase in body weight is due to higher levels of protein synthesis/formation (muscle mass) but also increased movement and storage of water in muscle tissue. (Looking and feeling slightly bigger just as creatine intake starts is not therefore miraculous growth, but probably just this increase in water storage in the muscle cells)
Most studies into the side-effects of supplementing with creatine have been unable to come upon any notable adverse effects, even after relatively long-term ingestion. This being said, it most be noted there are no completed long term (>5years) studies. Mild digestive system disturbances, such as mild diarrhoea or cramps, have been reported occasionally during the initial loading phase of creatine supplementation.
Increased fluid intake is often recommended, as increased water in the muscle tissue means less to other parts of the body, such as the heart and brain. Creatine is frequently recommended to be taken or mixed with simple sugary foods or fruit juices, as absorption out of the digestive system into the bloodstream is enhanced in the presence of sugars.
Note: Creatine has possible negative interactions with NSAID’s (non-steroidal anti-inflammatory drugs), caffeine, diuretics and some gout treatments.
Remember, your doctor knows best.
Jed
Creatine is utilised in muscle tissue (in the form of creatine phosphate - CP) to reform the high-energy/energy storing compound ATP, particularly during short-term, high intensity movements and activity. Over time, CP stores in the muscles are used up and one becomes unable to maintain high intensities in, for example, sprinting or lifting weights. Supplementing with creatine therefore helps to delay this fatigue.
It has also been shown to increase strength and body weight gains, as well as improve recovery after workouts/training. Increase in body weight is due to higher levels of protein synthesis/formation (muscle mass) but also increased movement and storage of water in muscle tissue. (Looking and feeling slightly bigger just as creatine intake starts is not therefore miraculous growth, but probably just this increase in water storage in the muscle cells)
Most studies into the side-effects of supplementing with creatine have been unable to come upon any notable adverse effects, even after relatively long-term ingestion. This being said, it most be noted there are no completed long term (>5years) studies. Mild digestive system disturbances, such as mild diarrhoea or cramps, have been reported occasionally during the initial loading phase of creatine supplementation.
Increased fluid intake is often recommended, as increased water in the muscle tissue means less to other parts of the body, such as the heart and brain. Creatine is frequently recommended to be taken or mixed with simple sugary foods or fruit juices, as absorption out of the digestive system into the bloodstream is enhanced in the presence of sugars.
Note: Creatine has possible negative interactions with NSAID’s (non-steroidal anti-inflammatory drugs), caffeine, diuretics and some gout treatments.
Remember, your doctor knows best.
Jed
Strength Training and Recovery times
As a response to a question we were posed on how to train muscles in the gym, do you train them all, all the time or not and how do rest days and recovery work?
It comes down to intensity. Intensity refers down to how much you are lifting and how many times you are lifting it. So basically it means how many reps and sets are you doing and how heavy are the weights? The higher the intensity of your work out the more time you will need to rest. So as an example if you are performing a strength and power training program, where you are lifting heavy weights and performing few reps for example doing 2-6 repetitions at 85-95% of your 1RM (1RM = one repetition maximum, the most you can lift in one push) then your intensity will be high and require a long period of rest between training days of the same muscle group. Equally if you are training for musclular endurance and performing 15-20 reps at a lower percentage of 1RM for example at 65% of your 1RM, a similar intensity will be achieved. Not to forget to also include the number of exercises you are performing per muscle group and how many sets you are performing of each exercise. So if you are performing only one exercise for the chest group using a strength training protocol (2-6 reps, 4 sets and more at 80-100% 1RM), your intensity will be far less than if you perform four exercises for the same muscle group.
So when training muscle groups, at high intensities, long periods of recovery are required and usually training a muscle group once per week is sufficient or up to twice a week at lower intensities to allow sufficient recovery time for the muscles to repair themselves.
Recovery of muscles involves the muscle repairing itself after damage due to overloading of the muscle fibres. DOMS (delayed onset muscle soreness) or commonly known as "being stiff" is a result not of the commonly thought of bad guy - lactic acid or lactate, whis has been shown to be removed within as little as an hour after exercise, but rather from actual structural damage of the muscle fibres and inflammation (the movement of certain cells such as white blood cells to the injured site to remove debris and initiate the healing process). So basically what happens in DOMS ("stiffness") is (Armstrong, 1984): high levels of tension in the muscles during training can result in actual structural damage to the muscle fibres and cell membranes. The resultant damage of cell membranes disturbs calcium homeostatsis (balance) which results in what is called necrosis or cell death which is at a peak after about 48 hours after the acute muscle damage. Then products of macrophage activity (macrophage - cell type from the immune system invade the injured area to remove debris and then invade again to aid in muscle regeneration) accumulate outside the damaged cells which stimulate free nerve endings (possible pain).
So recovery of muscle fibres can take days to repair themselves and sometimes even after the pain of DOMS subsides, it has been shown that muscles are still not fully reovered and not back to full strength. So firstly be aware of your damaged muscles and that if they are sore, they are not ready for exercise again, and that the harder you work the more recovery time you need until you train the same muscle group again and training a muscle group once a week is actually often beneficial as it allows the muscles to fully recover and for you to work it as hard again the next week and benefit from the strength and structural gains of the muscle.
JJ
It comes down to intensity. Intensity refers down to how much you are lifting and how many times you are lifting it. So basically it means how many reps and sets are you doing and how heavy are the weights? The higher the intensity of your work out the more time you will need to rest. So as an example if you are performing a strength and power training program, where you are lifting heavy weights and performing few reps for example doing 2-6 repetitions at 85-95% of your 1RM (1RM = one repetition maximum, the most you can lift in one push) then your intensity will be high and require a long period of rest between training days of the same muscle group. Equally if you are training for musclular endurance and performing 15-20 reps at a lower percentage of 1RM for example at 65% of your 1RM, a similar intensity will be achieved. Not to forget to also include the number of exercises you are performing per muscle group and how many sets you are performing of each exercise. So if you are performing only one exercise for the chest group using a strength training protocol (2-6 reps, 4 sets and more at 80-100% 1RM), your intensity will be far less than if you perform four exercises for the same muscle group.
So when training muscle groups, at high intensities, long periods of recovery are required and usually training a muscle group once per week is sufficient or up to twice a week at lower intensities to allow sufficient recovery time for the muscles to repair themselves.
Recovery of muscles involves the muscle repairing itself after damage due to overloading of the muscle fibres. DOMS (delayed onset muscle soreness) or commonly known as "being stiff" is a result not of the commonly thought of bad guy - lactic acid or lactate, whis has been shown to be removed within as little as an hour after exercise, but rather from actual structural damage of the muscle fibres and inflammation (the movement of certain cells such as white blood cells to the injured site to remove debris and initiate the healing process). So basically what happens in DOMS ("stiffness") is (Armstrong, 1984): high levels of tension in the muscles during training can result in actual structural damage to the muscle fibres and cell membranes. The resultant damage of cell membranes disturbs calcium homeostatsis (balance) which results in what is called necrosis or cell death which is at a peak after about 48 hours after the acute muscle damage. Then products of macrophage activity (macrophage - cell type from the immune system invade the injured area to remove debris and then invade again to aid in muscle regeneration) accumulate outside the damaged cells which stimulate free nerve endings (possible pain).
So recovery of muscle fibres can take days to repair themselves and sometimes even after the pain of DOMS subsides, it has been shown that muscles are still not fully reovered and not back to full strength. So firstly be aware of your damaged muscles and that if they are sore, they are not ready for exercise again, and that the harder you work the more recovery time you need until you train the same muscle group again and training a muscle group once a week is actually often beneficial as it allows the muscles to fully recover and for you to work it as hard again the next week and benefit from the strength and structural gains of the muscle.
JJ
Friday, February 19, 2010
Welcome to ExerQ
Thank you for visiting our exercise science blog - ExerQ. We are three young guys qualified in the field of Sports Science and currently doing our honours in Exercise Science. This blog is available to inform you on any current information in the science of exercise, fitness and sports.
We will cover topics regarding fitness, sports training, nutrition, current news and any questions you the readers have. Feel free to post comments on our posts or if you feel the need to know more about any particular topics or news and the science behind them. You can also join our facebook group, ExerQ - Exercise Science Q&A Blog.
We will start posting on Monday the 22nd of February 2010. Be sure to check it out...
Thanks
We will cover topics regarding fitness, sports training, nutrition, current news and any questions you the readers have. Feel free to post comments on our posts or if you feel the need to know more about any particular topics or news and the science behind them. You can also join our facebook group, ExerQ - Exercise Science Q&A Blog.
We will start posting on Monday the 22nd of February 2010. Be sure to check it out...
Thanks
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