Are you a morning or a night person when it comes to exercise? Does it matter? According to The American Council on Exercise there is a best time to tie on those sneakers and it varies by person. Here’s how to figure out when you should put fitness first. Start by paying attention to your body’s circadian rhythm that includes the physical, mental and behavioral changes that occur within a 24-hour cycle.Measure your temperature every few hours for five or six days. Write the results down and look for the time of day when your body is at its warmest. Right after you hit that high is when you should hit the gym, if possible. Studies show that for many people it’s late afternoon when performance and power tend to peak. No matter what your temperature log says, if you have a schedule that works for you, don’t feel pressured to change it. And if you’re training for a big event, try to practice at the same time of day that the event will be held.Remember, current guidelines recommend that children and teens get 60 minutes of physical activity most days of the week. Adults should get a minimum of 2 hours and 30 minutes of moderate-intensity aerobic exercise a week.I’m Dr. Cindy Haines of HealthDay TV with the news doctors are reading health news that matters to you.