• Events

    Running

    RunningCouch to 5K5K10KHalf MarathonMarathonSee All

    Outdoor

    OutdoorCampingHikingSee All

    Triathlon

    TriathlonSprintOlympic/InternationalIRONMAN 70.3IRONMANSee All

    Cycling

    CyclingRoad CyclingCentury RidesMountain BikingSee All

    Sports

    BaseballBasketballFootballGolfMartial ArtsSoccerSoftballSwimmingTennisVolleyballWinter SportsYoga

    hidden

    active kidsactive kidsSports CampsBrowse All EventsRace Results
  • Calculators

    Calculators

    Running PaceBody Fat PercentageBody Mass Index (BMI)Ideal WeightHeart Rate
    Caloric NeedsNutritional NeedsBasal Metabolic Rate (BMR)Kids' Body Mass Index (BMI)
  • Running

    Running Events

    RunningCouch to 5K5K10KHalf MarathonMarathonSee All

    Running Articles

    RunningDistance RunningTrail RunningMud RunningTraining PlansProduct Reviews
  • Triathlon

    Triathlon Events

    TriathlonSuper SprintSprintOlympic/InternationalIRONMAN 70.3IRONMANSee All

    Cycling Events

    CyclingRoad CyclingCentury RidesMountain BikingSee All

    Triathlon Articles

    TriathlonDuathlonTraining PlansProduct Reviews

    Cycling Articles

    CyclingMountain BikingCyclo-CrossBMXTraining PlansProduct Reviews
  • Fitness

    Fitness Events

    FitnessWalkingYogaStrength TrainingPilatesWeight LiftingSee All

    Fitness Articles

    FitnessWorkoutsWalkingYogaWeight LossTraining PlansProduct Reviews
  • Sports

    Sports Events

    BaseballBasketballFootballGolfMartial ArtsSoccerSoftballSwimmingTennisVolleyballWinter Sports

    Outdoor Events

    OutdoorCampingHikingBook CampgroundSee All

    Sports Articles

    SportsSwimmingBasketballTennisBaseballSoccerSoftballVolleyballFootballLacrosseGolf

    hidden

    Water SportsIce HockeyGymnasticsMartial ArtsSkiCampingHikingTravelSailingDanceSnowshoeing
  • Nutrition

    Nutrition Articles

    NutritionMeal PrepRecipesSnacksSupplementsProduct Reviews

    Health & Injury Articles

    Health & InjuryPhysical HealthMental HealthPainInjury PreventionRecoverySleepProduct Reviews
  • Kids & Family

    Kids

    Infants (0-1)Toddlers (2-4)Big Kids (5-8)Tweens (9-12)Teens (13-18)

    Events

    SwimmingBasketballBaseballSoccerTennisVolleyballFootballMartial ArtsChildcare

    hidden

    YogaCheerleadingGymnasticsDanceMusicArts & CraftsKids FitnessSee All

    hidden

    active kidsactive kids
  1. Home
  2. >
  3. Fitness Articles
  4. >
  5. Core Ab Training
Core Training

Featured

New Balance 2026 Spring Shoe Guide

Choosing the right running shoe is essential for comfort, performance, and injury prevention—especially as warmer weather invites more time outdoors.

By Stephen Gendreau

The Benefits of Running with a Group

Whether you’re thinking about joining a club or just want justification for your next happy hour run, I’m here to tell you why logging group miles ...

By Megan Harrington

How To Meal Prep For A Busy Training Schedule

Whether you’re gearing up for a high-mileage training block or just want to stay fueled while you handle life, meal prepping can be a game-changer.

By Megan Harrington

The Best Beginner Bikes of 2026: What to Buy (and What to Skip) for Every Kind of Rider

Road, gravel, or hybrid? With so many options and price points, buying your first bike can feel overwhelming. This guide cuts through the noise and...

By Marc Lindsay

Latest

The 80-Minute Training Plan

Crunched for time? This sample training plan includes practical workouts to help keep you on track.

By Marty Gaal

Lactate Threshold and V02 Max Explained

Should you get an LT or V02 max test? These questions answered, and more, in this breakdown of two commonly heard terms among triathletes.

By USA Triathlon 

6 Possible Reasons Why You're Gaining Weight

Your couch and the snack shelf are the most likely culprits, but these could be leading to weight gain, too.

By Prevention

6 Reasons to Join a Gym in the New Year

Ever drive by a gym on your way home from work? Here are six reasons to stop in next time and join.

By Jason R. Karp

Why Making New Year's Resolutions Is Bogus

Here are some reasons not to make resolutions this year, and what you can do instead.

By Christina Scannapiego

The 10 Commandments of New Year's Resolutions

You can succeed with your fitness resolutions this New Year if you follow a few simple rules.

By Jenny Hadfield

8 Bodyweight Exercises You Can Do Anywhere

Just because you're short on space doesn't mean you can't make time for a workout.

By Greatist

Why You Gain Weight In Your 20s, 30s and 40s

No matter how old you are, there's always something that can keep you from your goal weight.

By Women's Health

  • ACTIVE Logo
  • ACTIVE is the leader in online event registrations from 5k running races and marathons to softball leagues and local events. ACTIVE also makes it easy to learn and prepare for all the things you love to do with expert resources, training plans and fitness calculators.

Follow ACTIVE
  • Facebook
  • Twitter
  • Pinterest
  • Instagram
Mobile Apps
  • ACTIVE.com App
  • Couch to 5K®
  • 5K to 10K
  • Meet Mobile
  • View All Mobile Apps
Things To Do
  • Running Races
  • Triathlon Races
  • Cycling
  • Mountain Biking
  • 5K Races
  • 10K Races
  • More Things to Do
  • Half Marathon
  • Marathon
  • Ultra Running
  • Trail Running
  • Mud Runs
  • Swimming
Popular on ACTIVE.com
  • San Diego
  • Los Angeles
  • New York City
  • Denver
  • Houston
  • Las Vegas
  • BMI Calculator
  • Calorie Calculator
  • 5K Training
  • Couch to 5K®
  • Half Marathon Training
  • Marathon Training
  • Organizer Technology Solutions
  • Earn Money
  • Account Access
  • Subscribe to Our Newsletter
  • Do Not Sell My Personal Information
  • About ACTIVE.com
  • Sitemap
  • Terms of Use
  • Copyright Policy
  • Privacy Notice
  • Privacy Settings
  • Careers
  • Support & Feedback
  • ACTIVE Access
  • Advertise With Us
  • Registration Software
  • Social Media Guidelines
  • Community Policies
  • Cookies Settings
  • ©2025Active Network, LLC and/or its affiliates and licensors. All rights reserved.