I have had a pretty sore week this week. You know – the soreness you experience in muscles after extreme or unaccustomed exercise. I went on a karate course last Saturday and I’m only just getting over the pain! In fact, most weeks seem to be like this recently – I spend half my time experiencing stiff and sore muscles. Why? Is it my age? Am I working my muscles harder than usual? Am I not giving myself time to recover?
I decided to find out a bit more about post exercise muscle soreness, particularly in relation to age.
Apparently, with regular exercise, older people (older means over 30 in exercise circles – I know!) can still match the performance of their younger counterparts (even into their early 60’s) but their muscle physiology has to change to do it. In older people nerve fibres supplying muscle fibres start to die off and so there is a reduction in the number of muscle fibres. However, with exercise these fibres increase in size and can perform the same work as groups of small fibres. In other words, young people have muscles composed of many smaller fibres and older people have muscles composed of fewer but larger muscle fibres.
However, although performance doesn’t have to decline (assuming that the young and older person are doing the same level and intensity of training) the time taken to recover afterwards does increase with age and longer rest periods are required in between exercise sessions.
This post exercise muscle soreness is called Delayed Onset Muscle Soreness (DOMS) and is felt most strongly in muscles 24 – 72 hours after the exercise. It is a symptom of muscle damage caused by eccentric muscle contraction. An eccentric muscle contraction is one where the muscle contracts but lengthens at the same time – running downhill or downstairs is a prime example.
Well, I did one and a half hours of sparring practice last Saturday – bouncing backwards and forwards on the balls of the feet for most of that time, followed by some vigorous skipping at karate on Monday and some fairly intense kicking practice on Wednesday. All of these activities involve eccentric muscle contractions so it is not surprising that I am suffering from DOMS!Another interesting fact about DOMS (according to Wikipedia) is that soreness is only one of the temporary changes caused in muscles by unaccustomed or extreme eccentric exercise. Other such changes include decreased muscle strength, reduced range of motion and muscle swelling. It has been shown, however, that these changes develop independently in time from one another and that the soreness is therefore not the cause of the reduction in muscle function.
This is interesting to me because in karate class on Wednesday my legs felt weak, but not necessarily in the places where the soreness was. We were practising kicks over a chair to make sure we lifted the knee high before extending the kick. My legs definitely lacked the power needed to lift my legs in this way so I wonder if I had a bit of muscle swelling as well.
DOMS can take anything from 2-7 days to recover from. Research done on rats suggests that recovery is slower in older people (well, older rats at least) because they have lower levels of growth hormone and testosterone, both of which aid in muscle recovery. Muscles also tighten with age and blood circulation can be slower.
What I was interested in finding out was whether there is there anything you can do to either prevent DOMS from occurring or speed up the recovery period? I was surprised to find that there is not a lot you can do to prevent DOMS, other than avoid eccentric muscle contractions, and that pre-workout warm ups and post workout cool downs make no significant difference. Stretching also makes little difference though it might help older people more by increasing blood flow to muscles.
The only thing that has been shown scientifically to reduce the intensity of DOMS is light aerobic exercise at the end of a workout. Other more anecdotal suggestions include massage, hot baths or a sauna which are thought to help because they increase the blood supply to the muscles.
If there is not much we can do to prevent DOMS developing is there anything we can do to hasten recovery? Again, there are many anecdotal remedies including taking an ice bath, applying muscle compression or doing yoga. Research though suggests that exercising sore muscles is the best way to reduce or eliminate soreness. The degree of soreness does not reflect the magnitude of muscle damage and exercising sore muscles does not damage them further.
Other factors that appear to be important are getting adequate sleep – 8 hours a night is recommended, reducing mental stress and eating a balanced diet rich in micro-nutrients.
So, what have I learnt here that is useful to me? Well, the good news is if I train hard I should be able to keep up with the youngsters in our karate class. The muscle soreness I’m experiencing isn’t a cause for concern – just inconvenient and it is perfectly safe to continue exercising through it. In fact it seems that it is preferable to continue exercising through it as it may help speed up recovery from the soreness. I also know that I need to try and get more sleep; I’m not sleeping to well at the moment (partly due to the soreness). Perhaps a hot bath after karate class would help reduce soreness AND promote better sleep? Mmmmm…I like the sound of that…..
Do you have any advice on the prevention or reduction DOMS?