If you are a high level athlete putting in long training hours
The more training required of an athlete, the more carbohydrate that needs to be present in the diet. Using spiralized vegetables instead of pasta noodles cuts down significantly on carbohydrate content of the meal. This is not entirely bad if the athlete is then getting carbohydrate from another food source, such as fruit, bread, etc. However, that carbohydrate does need to come from somewhere, as lacking carbohydrate intake on a daily basis can lead to poor recovery, increased risk of injury and a weakened immune system.
If you are prepping for a long competition
While you may not all consider yourselves high-level athletes, perhaps you do compete in endurance competitions once in a while. Any time an athlete is preparing for a long-distance bout of exercise, the practice of "carb loading" is common the night or week before. This practice helps load up the muscles and liver with carbohydrate (glycogen) to be available to the body during the exercise bout. So, if spiralized vegetables are used instead of pasta noodles, be sure to get the appropriate amount of carbohydrate from elsewhere.
If you want to lose weight
This is one area where spiralized vegetables shine. A downfall of many athletes trying to lose weight is overconsumption of pasta. Go to any Italian restaurant and portions are near an entire box of pasta for one person. Using spiralized vegetables in place of the pasta noodles is a great and easy way to cut down on carbohydrates and calories. This can be very beneficial for weight loss.
If you have a gluten allergy
Because regular pasta contains gluten, individuals with a gluten allergy, or celiac disease, are forced to alternatives such as gluten-free pasta or spaghetti squash. Enter the spiralizer. So many more options! What a great way to expand your recipe book.
If you have a problem getting in enough vegetables
I'm pretty sure I've never started a sentence in my office with, "You know, you could cut down on vegetables..." My one caution here is to be careful what you put on those spiralized vegetables. The vegetables are fantastic....the vegetables covered in butter and cheese are really not doing you all that much good, even if you are hitting your vegetable intake.
So the answer is...it depends. Assuming you eat other sources of carbohydrate outside of pasta, this trend likely won't hinder your performance goals.
Here is a recipe to get you started. How amazing does this sound?! This recipe is pictured above; recipe source here.
Avocado-Basil Zucchini Noodles with Chili-Lime Shrimp & Corn