Being dehydrated as we know can reduce performance, the higher the dehydration the less you can perform. However, there are two components of sweat that we must consider and manage. Volume and concentration, most of us have a good idea of the volume that we sweat. However, the concentration of sweat is especially important for hydration and is sometimes overlooked. If you are a salty sweater, you will have to pay extra attention to your sodium intake to nail your hydration.
Ever finished a race or long ride covered with layers of salt all over your kit and skin? This is a sign that the content of your sweat is high in sodium and might get worse in dryer conditions. It becomes important to consider when racing a stage race or doing a heavy training block. It is a sign to increase your sodium intake in your diet, this will help recovery and will prevent issues like muscle cramps from occurring.
When your sweat burns your eyes or skin. Another sign that you are losing too much sweat.
If you suffer from cramping during long rides/races or training sessions, this might also indicate that you are losing too much salt or not taking in enough during the ride.
Something that I have noticed recently, post exercise you sit down for an extended period and when you wake up you immediately feel faint or lightheaded. The medical term for this is called orthostatic hypotension which means low blood pressure. When you lose too much sodium through sweat your blood volume/pressure drops. So, when you stand up blood cannot reach your brain fast enough, the lack of oxygen leaves you feeling lightheaded.
If you experience the above signs, the solution would be to take in more sodium before, during and after exercise. You can do this by adding salt to your meals/foods, changing to a more potent hydration drink or by having an extra bottle of electrolyte mix after your sessions. If you experience all the above signs as I have, shop around for stronger electrolyte drinks. These will contain at least 1,000mg of sodium per litre.