When I gave birth to my first child in 2005, I was looking at different options on how to lose weight. It happened to be around the time that HIIT (High Intensity Interval Training) workouts were becoming increasingly popular. So I spent 20-40 minutes doing HIIT workouts three times a week. I ended up losing 60 lbs. in six months! It was a game changer. I found something where I didn’t have to spend hours in the gym, but could still burn a crazy number of calories. I now try to incorporate HIIT into my group and private fitness classes as much as I can.

HIIT continues to be one of the most effective training styles used by individuals, personal trainers, and in group fitness programs all over the world. It can be incorporated in a spin class, using a rowing machine, using weights (like dumbbells or kettlebells), or by simply exercising without any equipment at all.

There’s a stigma that HIIT is all about cardio, but it also helps to add muscle and eliminate stubborn fat. The base formula is the harder you work (the higher the intensity) = the higher your oxygen intake = the higher the number of calories you burn. The combination of short bursts of high intensity exercises of 20-90 seconds with rest periods of 10-60 seconds in between help burn more calories both during your workout, but even better, for a period of time after your workout is complete.

For most good things, there’s always a “but” not far behind. As efficient as HIIT is, most of the exercises are usually high impact and include a variety of jumping. This can cause wear and tear on the body, leading to injuries in the muscles and joints. The general rule is “everything in moderation”. That also goes for HIIT. Using my background in Kinesiology and personal training, I have modified HIIT in my classes and training to minimize the risk for external pounding or jarring on the joints. This makes my classes more accessible to clients of all different levels, providing everyone the benefits of boosting their endurance and increasing fat loss. Clients get to grow at their own pace and choose the level their body can manage that day.

The modifications I’ve incorporated include low impact exercises or LIIT (Low Intensity Interval Training), which has been proven to have a positive effect on clients. Don’t underestimate the acronym. These exercises can still achieve a high calorie burn workout. Examples of low impact exercises I use include the inchworm, modified power jacks, mountain climbers, skaters, and knee drives. Clients often associate low impact training as a “light day”, which is far from the truth. You can still reap the fat-burning, metabolism-boosting benefits of a HIIT workout with low impact exercises. If the intensity of your work-to-rest ratio is right, and the intensity of your workout is high enough, you can burn an equal number of calories. Just keep moving!

I believe part of the responsibility about being a personal trainer is to bring all possible solutions and methods to our clients, educating them and breaking stigmas. This includes meeting them where they are and leading them through their own path of progress, not to perfection.

With the holidays around the corner, I’ve included a quick 20-minute LIIT workout you can share with your clients or try for yourself.

Instructions: Do each exercise listed below, performing each move at maximum intensity for 45 seconds and follow with 15 seconds of rest by stepping side-to-side or walking around the room to catch your breath. Complete four total rounds.


  1. Start with feet hip-width apart, hands at sides.
  2. Hinge forward from your hips and place palms on the mat, bending knees as needed to reach hands to the floor.
  3. Walk hands forward to a plank position, shoulders above wrists.
  4. Walk hands back to feet and hinge from hips back up to stand.

Modified Standing Jacks

  1. Stand straight with feet together, hands at sides.
  2. Step to the right and bring both hands above the head.
  3. Bring right leg in, lower arms and return to the starting position.
  4. Repeat with the left leg, alternating sides.
NIKE CHARLES Modified Standing Jacks

Modified Mountain Climbers

  1. Start in a plank position, shoulders above wrists.
  2. Step left knee in towards chest then step it back.
  3. Repeat with right knee, alternating back and forth.
NIKE CHARLES Modified Mountain Climbers


  1. Start with feet hip-width apart, hands at your sides.
  2. Step back with left leg into a diagonal lunge.
  3. For added momentum, swing left arm in front of front knee.
  4. Come back to start position, repeating on the other side.


  1. Start with feet hip-width apart, toes pointed forward.
  2. Keep weight in heels and hinge at the hips, bend the knees, and sit down and back, keep head and chest up.
  3. Push through heels to come back to the start position.

Adenike (Nike) Charles is the owner of JUST2SWEAT studio where faith and fitness transform lives! She holds a BSc in Kinesiology and a Minor in Sports Medicine and is a canfitpro PTS. Nike thrives on seeing people living healthy and active lives. Connect with her @just2sweat on all social media platforms.