DOMS

Put the squeeze on soreness

Anyone who undertakes a new exercise or activity involving eccentric muscle work is likely to feel the effects afterwards in the form of the dreaded ‘DOMS’ (delayed onset muscle soreness). While this can be experienced as a tolerable muscle ache that serves as a reminder of one’s virtuous hard work, in more severe cases it can be a very painful and debilitating experience that will hang around for a week, compromising functional ability while it lasts.

There has been a lot of interest in the supposed ability of compression clothing to ameliorate the DOMS effect by reducing the extent of muscle microdamage that occurs during unaccustomed eccentric loading, thereby helping to maintain muscle function. Compression garments are big business: these days pretty much all of the big hitters in performance apparel are running clothing lines boasting ‘compression’ properties. But there is little research into how and why these clothes might make a difference.

Researchers based in Australia have recently investigated whether compression garments could aid metabolic recovery from eccentric exercise

(Compression Garments and Recovery from Eccentric Exercise, Journal of Sports Science and Medicine 2006; 5:106-114).

Eleven male recreational athletes took part in the study. Each participant performed a downhill walk for 30 minutes on a treadmill at 6kph and a 25% gradient. Immediately after this exercise and for the next 48 hours, the subjects all wore graduated compression garments that covered the calf and thigh on one leg (Skins: 76% nylon and Meryl microfibre, 24% Roica spandex). The leg wearing the compression garment was randomly assigned between dominant and non-dominant legs. Perceived muscle soreness of each thigh was assessed using a scale of 1 (no pain at all) to 10 (very, very sore).

The research team used phosphorus magnetic resonance spectroscopy to measure metabolic changes at a cellular level in order to establish whether compression garments could reduce muscle metabolite changes and promote cellular repair.

Measures were taken one hour and 48 hours after exercise and seven metabolites were analysed:

1. ATP – adenosine tri-phosphate: the energy currency of the cell, transfers energy from chemical bonds to energy-absorbing reactions within the cell.

2. PCr – phosphocreatine: an important energy store in skeletal muscle, used to generate ATP.

3. PDE – phosphodiester: phosphodiester bonds are central to all life, as they make up the backbone of DNA strands.

4. Pi – inorganic phosphate: phosphorus found as a free phosphate ion in solution.

5. PME – an organic ester of phosphoric acid (compound formed by removal of water).

6. pH – measure of acidity of a solution (the lower the number the more acidic the solution).

7. Mg2+ – Free magnesium is an essential part of the chemistry of life, and thus is essential to all cells of all known living organisms.

The results of this study showed that the wearing of compression garments produced a relative increase in PDE (and therefore increased cell membrane turnover) in the thigh one hour after eccentric exercise. At the same point in time pH levels were down, too, but in both legs, and compression garments had no significant effect on pH compared to the control leg. There were no observable differences in PCr/Pi, Mg2+ or PME over time. Perceived level of muscle soreness was elevated at all time points after exercise, with compression garments making no difference to the pain experienced.

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Elixir to soothe the pain

If recent research from the United States is anything to go by, it looks as though good old Vitamin C could go some way to helping prevent the nastier effects of DOMS. Researchers based in the exercise and sport science department of the University of North Carolina have been investigating whether Vitamin C supplementation before and after eccentric exercise can reduce muscle soreness, oxidative stress (damage to cells caused by an imbalance between pro-oxidants and anti-oxidants) and muscle function (Effect of High dose of Vitamin C Supplementation on Muscle Soreness, Damage, Function and Oxidative Stress to Eccentric Exercise, International Journal of Sport Nutrition and Exercise Metabolism 2006; 16: 270- 280).

Eighteen untrained males who had undertaken no resistance training in the previous six months were randomly assigned to either a placebo or Vitamin C group. The subjects took the supplements (3g per day) for two weeks prior to the eccentric exercise trial, and continued to take the pills for four days after the exercise session.

Muscle soreness was assessed on a 1 to 10 reporting scale and range of movement was assessed with a goniometer. The exercise testing used an isokinetic dynamometer and consisted of 70 eccentric muscle actions (on the non-dominant arm with maximal voluntary effort), using the elbow flexors from 5 degrees from full flexion to 5degrees from full extension. Blood samples were taken immediately after the trial, along with muscle soreness and ROM assessments. The subjects repeated the measures at four hours and then one, two, three and four days later.

Both groups experienced increased muscle soreness but the level was significantly lower for the Vitamin C group. The overall pattern of muscle soreness, however, remained the same for both groups, so, although it started off at a lower level in the Vitamin C group, it dropped off thereafter at the same rate as in the control group. Decreases in force production and ROM were similar in both groups and there were no significant differences in the rate of recovery over time. Plasma creatine kinase (CK) activity (an indicator of muscle damage) increased significantly between 48 hours and 96 hours (this is to be expected) and the researchers found only a slight reduction in creatine kinase activity in the Vitamin C group. While they describe this as ‘non-significant’, to practitioners, it does suggest that there is a potential benefit to be had with supplementation.

As to why the Vitamin C group seemed to be benefiting from reduced levels of muscle soreness, the researchers offer only a tentative theory. Glutathione is a powerful antioxidant, involved in detoxification, with some research suggesting that it has protective mechanisms against a number of forms of cancer. The results of this study showed a significant increase in the ratio of oxidised glutathione to total glutathione at 4 hours and 24 hours only in the control group. The Vitamin C group had significantly lower ratios in comparison, which may be related in some way to the protection from muscle soreness seen in the Vitamin C group.

The research team from North Carolina concluded that high dose Vitamin C for two weeks prior to, and continuing for four days after, eccentric exercise can reduce muscle soreness, with little influence on loss of range of motion, or maximal isometric force and CK response.

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