Gelatin desserts? I feel like the desserts would be less successful than yogurt, oatmeal, and mashed potatoes.
I think one thing you could do in order to measure your cardiovascular strength you can do a full sprint run. In order to help improve your fitness levels you can swim, jog/run, body weight exercises, and a balanced diet.
Answer: Its Good to be very flexible.
Explanation: You'll find that most athletes, take a lot of time to include stretching in their training for their sport's. Most athletes do Yoga or Gymnastics. Being Flexible Is good but especially for athletes it is great because it brings that chance of getting injured or cramped while training while doing their sport to a much lower level.
I hope I helped! :D
