This time, I'd like to talk about muscle cramps and hydration.
Do you ever experience muscle cramps in hot weather like summer, or during or after a workout?This can happen to anyone, and one of the best ways to deal with it is to rehydrate.
When you're in the middle of a cramp, you'll do whatever you can to get rid of it, but I'm not sure if rehydration is the right way.
There are other methods, such as oral rehydration solution like OS-1, which can replenish electrolytes, but I would like to introduce a research paper on which is better.
The research
Previous studies have not compared the effects of post-dehydration and oral rehydration solution (ORS) intake induced by exercise in the heat on muscle cramps.
This study tested the hypothesis that post-dehydration fluid intake increases susceptibility to muscle cramps, which can be prevented by ORS intake.
The content of the study was based on 10 men.
They were asked to perform two downhill runs (DHR; -5%) in heat (35°C-36°C) until they lost 2% of their body weight.
Ten minutes after the DHR, they were allowed to consume water or ORS on different days.Susceptibility to muscle cramps was assessed by the threshold frequency (TF) of electrical train stimulation to induce cramps before, immediately after (0), 30 and 60 minutes after ingestion.
Blood samples were collected before, immediately after, and 80 min after DHR to measure serum electrolyte concentrations.
As a result, susceptibility to muscle cramps as assessed by TF did not change from baseline to immediately after DHR in both conditions (water: 24.6 ± 2.1 Hz, OS-1: 24.7 ± 1.4 Hz).
TF decreased by 4.3 Hz (30 min) and 5.1 Hz (60 min after intake) after fluid intake, but increased by 3.7 and 5.4 Hz, respectively, after OS-1 intake.
Serum sodium and chloride concentrations decreased after fluid intake, but were maintained after OS-1 intake.
In conclusion, fluid intake after dehydration causes electrolyte dilution, which can lead to muscle cramps.
The results suggest that OS-1 intake reduces the susceptibility of muscles to cramping.
Discussion
The results of the study showed that when muscle cramps occur after a loss of 2% of body weight in water, rehydration may cause cramps, but oral rehydration solution intake reduces the likelihood of cramps.
The reason for this may be that the fluids taken after dehydration may dilute the electrolytes in the blood. This was thought to be the reason.
Since the study involved only 10 subjects and was funded by the manufacturing company (Dai 00 Pharmaceutical), I wonder if it is safe to believe the results. I'm not sure.There is a statement that there was no monitoring from the funding source, but...
It is said that the dilution of electrolytes, especially sodium and chloride, may cause muscle cramps. It is said that the dilution of sodium and chloride in particular may cause muscle cramps.
It may be a good idea to pay attention to this point on a regular basis as well.
Trainers and other health care professionals involved in exercise can deal with muscle cramps even if they only know about these things.
Well, if we are going to encourage the same kind of fluid intake, why not use oral rehydration solution rather than just "water"? That's right.
It can be taken during or after exercise.
It's important to be able to take care of yourself in this way, but it's also important to manage your physical condition before you exercise. And.
For your reference
Ingredients of oral rehydration solution
Sodium (2970 mg / L)
Potassium (794 mg / L)
Magnesium (25 mg / L)
Chloride (1801 mg / L)
Glucose (18 300 mg / L)
Water
Sodium (2 mg / L)
Potassium (0.5 mg / L)
Magnesium (18 mg / L)
Chloride (1.2 mg / L)
Supplement
In the measurements made during the study, it was also discussed that maybe just adding glucose to the water would help? This was also discussed.
The reason for this is that the oral rehydration solution used in the experiment contained glucose, which may have reduced the possibility of muscle cramps due to the effect of glucose rather than the effect of other electrolytes.
This is because glucose is one of the different ingredients in water and oral rehydration solution, so the effect of glucose cannot be ruled out in these results.
Lau WY, Kato H, Nosaka K. Water intake after dehydration makes muscles more susceptible to cramp but electrolytes reverse that effect [published correction appears in BMJ Open Sport Exerc Med. 2019 Apr 11;5(1):e000478corr1]. BMJ Open Sport Exerc Med. 2019;5(1):e000478. published 2019 Mar 5. doi:10.1136/bmjsem-2018-000478
Conclusion
One of the factors that cause muscle cramps is the dilution of electrolytes in the blood due to the water used to replace the water lost during exercise.
In order to deal with the resulting cramps, it is advisable to supplement with fluids such as oral rehydration solution.
There are some points to consider, such as "Isn't water mixed with glucose okay? However, as we are still waiting for additional research, we should trust that the results of the study can be reproduced with oral rehydration solution.
