Firstly, you need to know this… 1. 20% of energy during exercise is used for muscular activity – the shearing or woolhandling part
2. 80% is used when we sweat (the dripping off the nose part)
3. Dehydration is affected by a. Fluid intake b. Heat c. Fluid loss d. Exercise
e. Our own bodies
So, when you are dehydrated, from working in a hot shed, or sweating a lot, or not having enough fluid on board to start with your body does not function as it should.
Then if you aren't careful, you lose too much fluid become more dehydrated and following this, there is a variable (and most likely individualistic) level of how much it affects strength, power and speed, endurance, skill and technique and cognition - hence the reason to avoid dehydration when trying to perform in the woolshed.
Any thing that makes you slower, or less strong in the shed is detrimental to your performance, but if you lose more than one of these things you need, your tally, and therefore your back pocket are going to take a hit. Plus, you are going to recover more slowly, so it's not just the day you are dehydrated that it's a problem.
1. Strength – (this is the maximal force you can produce at a certain speed, e.g. positioning the sheep during shearing when going at a steady pace) when dehydrated, you cannot produce the same amount of force as you can when you are “optimally hydrated”
2. Power and Speed (how quickly you can move something heavy, e.g. the catch and drag, or positioning the sheep when shearing at pace) – this is affected the most out of all the factors by dehydration, you are not able to move the sheep so quickly when you are dehydrated.
3. Repeated power and speed– as for above, you have some diminished strength, but as you repeat the exercise there is a significant decrease in ability to move the sheep quickly. So you get slower, and the job gets harder through the day.
4. Endurance – you cannot keep going for as long, because your muscles just won’t do it - the chemicals and nutrients needed are not available.
5. Skill and Technique – You lose skill and technique as you become more dehydrated, so it’s harder still to do a good job, (as if losing power, strength and endurance isn’t enough) as you lose all the little tricks in your pattern that you have that make life easier. (This is affected differently with different people, and having greater skill level means that you are less likely to have an effect)
6. Cognition (how clever your brain is) – this lapses when you are dehydrated too – but comes back quicker than the first four when you get your fluid levels back up.