Seminar on bioidentical hormone replacement in men and women, with speaker Nyna Nelson. 7-9 p.m. Professional Village Compounding Pharmacy, 1701 Professional Drive, Sacramento. Free. (916) 483-3455.
10th annual National Wear Red Day. Wear red to raise awareness of heart disease; Go Red Strut around the mall with a stroller-decorating station and free health screenings from Sutter Heart and Vascular Institute. 10 a.m.-2 p.m. Arden Fair mall, 1689 Arden Way, Sacramento. Free. (916) 920-1167.
Dirty Duathlon. Run two miles, mountain bike 6.5 miles, then run two more miles. 7-10 a.m. packet pickup, 10 a.m. race start time. Folsom Lake State Recreation Area, Granite Bay, off Douglas Boulevard. $50-$60 general; $40-$50 ages 18 and younger; $80-$90 relay teams. (916) 202-3006.
Gumby 5K, 10K and free one-mile kids race, awards presented in each division and raffle prizes. 8 a.m. Folsom Lake State Recreation Area, Granite Bay, off of Douglas Blvd. $45-$55. (916) 202-3006.
MTB Classic cross-country mountain bike race. Challenging, scenic, fast single-track trails up and down the foothills surrounding Folsom Lake. Divisions for juniors, novices and experts. 7 a.m. packet pickup; 9 a.m. start time. Folsom Lake State Recreation Area, Granite Bay, off of Douglas Blvd. $50-$55 general, $40-$45 ages 18 and younger. (916) 202-3006.
Healthy Heart class. A registered dietitian will discuss healthful and unhealthful fats, cooking tips and grocery shopping guidelines. 10- 11:30 a.m. 6555 Coyle Ave., Room 150, Carmichael. Free. (916) 537-5296.
The UC Davis School of Medicine's 2013 Nelson Scientific Lecturer, Sir Andrew McMichael of the Weatherall Institute of Molecular Medicine at the University of Oxford, titled "T-cell Immune Responses Against HIV-1: Can They Be Harnessed by Vaccines?" Noon in the auditorium of the Genome and Biomedical Sciences Facility, 451 Health Sciences Drive, UC Davis; and 5 p.m. in the Matsui Lecture Hall of the Education Building, 4610 X St., UC Davis Health System, Sacramento. Free. To reserve a seat, email firstname.lastname@example.org, or call (916) 734-9101.
Community cholesterol screenings. Receive results within 10 minutes for liquid panels and glucose. Cholesterol counselors will be available to explain results and offer suggestions on how to improve values. 8-10 a.m. Mercy General Hospital, 4001 J St., Sacramento. $25-$30. (916) 453-4521.
Dignity Health health seminar. Discover treatments for ankle conditions and procedures performed by Dr. George Lian, orthopedic surgeon. 6:30-8 p.m. Arden Hills Country Club, 1220 Arden Hills Lane, Sacramento. Free. Registration required. (916) 851-2511.
The 10th annual Valentine Run will benefit the Legal Services of Northern California. All ages welcome. Stroller and dog friendly. Live music and prizes. 7 a.m.-noon. Country Club Plaza Mall, 2310 Watt Ave., Sacramento. $25-35 general. $16-20 for children's races. Registration required. 916-551-2164.
Girls on the Go Run for Women and Girls. Join more than 1,000 mothers, daughters, sisters, grandmothers and friends in a 5K or 10K walk/run. All fitness levels and strollers welcome. The finish line includes a Girlicious medal, T-shirt and festival. 8 a.m. Crocker Park, Third and O streets, Sacramento. $30-$50. Register at girlsonthegorun.com. (619) 491-0677.
Polar Plunge. Gather your brave friends and family, and dive into 50-degree water to raise money for patients with spinal cord injuries. 8 a.m. Fruitridge Community Center, 4000 Fruitridge Road, Sacramento. $20. (916) 599-0873.
Demystifying Fat. Learn about healthy fats and their benefit in total body wellness, led by Antonella Aguilera-Ruiz, ND, offered by the Sacramento Natural Foods Co-op. 6:30- 8 p.m. 1900 Alhambra Blvd., Sacramento. $15, $10 Co-op owners. (916) 455-2667.
West Roseville Volkswalk, a walk sponsored by the Placer Pacers, will be on bike paths and city streets. Strollers and wheelchairs are OK. Registration 8:30 a.m. to noon; complete walk by 3 p.m. Roseville Aquatic Complex, 3051 Woodcreek Oaks Blvd., Roseville. Free; $3 for AVA/IVV event and distance programs. (916) 733-9371.