It is 9:45 a.m. on a Wednesday morning in Oceanside, Calif., and the crown jewel of the Jazzercise class schedule is hitting its stride. It’s called Dance Mixx, and it’s taught by Shanna Missett ...

It is 9:45 a.m. on a Wednesday morning in Oceanside, Calif., and the crown jewel of the Jazzercise class schedule is hitting its stride. It’s called Dance Mixx, and it’s taught by Shanna Missett ...

“We are so proud of our history,” says Teresa Wagstaff, who’s been teaching for 16 years and started her own franchise 15 years ago. Next year, the fitness program turns 50. Wagstaff says it has ...