You can never run all out many things will happen in your unconscious mind to protect your body from , well , death basically . t r a i n i n g a r t i c l e scentralgovernortheoryKey phrase from that articleBy going out too fast during a race , you kick in the central governor early and even elicit physiological changes by the brain designed to slow you down . OP It ' s totally normal to feel wheezy in temperatures of freezing . One of the reasons I move my training indoors to the dreadmill when winter kicks in . I get this as well but it ' s normal . Congratulations on Time Trialling a 3 k , it ' s not a sprint that ' s for sure ! You ' ve forced your body to make some adaptations ahead of your next attempt . Take a note of the time , and make some notes about how you felt beforeduringafter .