Summary
Highlights
Dennis ranks swimming as his best cardio due to high calorie burn and enjoyment, and sprints as his worst due to intensity and non-sustainability. Jeremy ranks regular walking as his best for consistency and general lifestyle, and sprints as his worst for fat loss. The video concludes by emphasizing that effective fat loss requires a combination of cardio, strength training, and most importantly, a proper diet to ensure a calorie deficit.
The video introduces the use of a highly accurate calorie tracker to test 12 popular cardio exercises, measuring total calories, fat burn, and carb burn. The first exercise tested is jump rope, and Dennis joins to see how fitness levels affect results.
The hosts perform a HIIT jump rope workout. Jeremy burns 146 calories in 10 minutes, while Dennis burns 69. The afterburn effect for jump rope is found to be minimal, adding only 28 extra calories for Jeremy and 8 for Dennis over 20 minutes, as their heart rates didn't reach true high intensity levels.
They try a popular YouTube HIIT workout. In 10 minutes, Jeremy burns 136 calories and Dennis burns 100. The afterburn for this workout is also low, with Jeremy burning 24 extra calories and Dennis 16. Jeremy notes that his heart rate still didn't reach maximum intensity.
Sprints are introduced as the 'king of HIIT'. In 10 minutes, Jeremy burns 178 calories (17.8 calories/minute), and Dennis burns 148, making it their highest calorie burner so far. However, 97% of the calories burned by Jeremy were from carbs, with only 3% from fat. Sprints show the highest afterburn yet, with Jeremy burning 48 extra calories and Dennis 27.
The video explains that the afterburn effect of HIIT is often exaggerated, noting that less intense cycling still produced a significant afterburn. It suggests that resistance training is a better choice for afterburn, as it also helps maintain and build muscle.
They try jogging for 20 minutes, with Jeremy burning 350 calories and Dennis 260, nearly double the sprints due to sustained elevated heart rates. They then test fasted cardio (jogging on an empty stomach) which results in a higher percentage of calories burned from fat. However, Dr. Eric Helps clarifies that fat burn and fat loss are different; long-term fat loss depends on overall calorie deficit, not just what's burned during a single session.
To reduce joint impact, they try Kanga Jumps (bouncy boots). While they feel easier on the knees, they make running harder, and result in 10% fewer calories burned than regular jogging. The boots are also expensive and uncomfortable.
Swimming is presented as a great, joint-friendly exercise that works almost every major muscle group and burns extra calories to stay warm. Despite a cumbersome setup with a dry suit and mask, they manage to burn 276 calories (Jeremy) and 223 calories (Dennis) in 20 minutes.
Walking for 30 minutes at 3.2 mph burns almost 200 calories each, with 80% coming from fat – the highest fat burn percentage so far. The video highlights that total calorie burn matters, and walking can add up (2.5 hours extra walking per week led to 3.5 lbs of fat loss in a study). They test incline walking (50% more calories burned than flat walking) and walking with a weighted backpack (13-30% more calories).
They test the Stairmaster, with Jeremy burning 256 calories and Dennis 215 in 20 minutes. Next, they try an intense boxing workout for 20 minutes, where Jeremy burns 270 calories. The hosts note that boxing felt harder but Stairmaster was more relaxing.