WHAT IS BEST FOR FAT LOSS: CARDIO OR HIGH INTENSITY TRAINING

HAPPY NEW YEAR TO ALL OF YOU!

Before I begin I would like to mention to all the readers and my friends who love running marathons and do the century bike rides that they continue what they are doing because it is commendable and requires a lot of discipline to do what they do and is very healthy to do so. In this article I am only making an attempt at clarifying the purported benefits of cardio for fat loss.

So, what is best for fat loss? Long duration low intensity aerobic or short duration high intensity anaerobic training? Most of us think it has to be the former because that’s what we have been told by the ‘experts’ that low intensity high volume training is best for fat loss. The proponents of cardio (or aerobics) even say that the body doesn’t start ‘burning fat’ until after 20-30 min of the cardio workout. So the widely accepted prescription for fat loss is to do aerobics for 30 to 60 min, 3-5X a week. 

Now take a look at the two athletes shown here. The one on the left is current world marathon record holder Samuel Wanjiru, an epitome of low intensity long duration cardio, and the one on the right is the current world record holder in 100m sprint, Usain Bolt, an epitome of short duration high intensity training. Which one do you think has the lower body fat percentage? In case it’s not obvious from the pictures that would be the sprinter! 

A closer look at the training regimen of Wanjiru shows that he alternates 30km at a moderate pace and 38km cross country at a low pace every 10 days. On top of that he runs 15km every morning before he eats breakfast. In his own words he never does any strength training. So do you think he gets enough cardio? I think he gets plenty! Now a closer look at Bolt’s training regimen shows that he trains with a combination of strength and plyometric training to build functional and explosive strength. The core of his workout program consists of weighted squats, lunges and explosive step-ups with weighted barbell and he likes to keep it heavy for a maximum of 10-12 reps. He also does a lot of high intensity interval training (HIIT) type sprint drills where he would sprint at full speed for 50 -100 yards and rest for a few minutes of stretching and flexibility followed by the full speed sprint. So do you think he gets enough cardio? It’s negligible to none! By the way both athletes are very healthy eaters as one would expect from any world class athlete. So the big question is why does Mr. Cardio have a higher body fat percentage than Mr. High Intensity? 

Let’s try to understand why this is so. Doing long duration cardio requires the body to be very efficient at spending energy. You see, nature is very frugal so it will always choose the lowest energy state. So going for hours of energy expenditure will require the body to lose weight (not just fat) in order to minimize the work done. And the body doesn’t discriminate between muscle and fat loss when it loses weight for the sake of being efficient. Moreover it’s more efficient to lose muscle (except the muscles involved in the activity) rather than fat as muscle is denser than fat. So in order to run a marathon the body has to lose muscle and fat from everywhere else except the legs. But we all know that losing muscle slows down your basal metabolism so while long duration cardio burns a lot of calories during the activity the body burns very little when the activity is not being performed. On the other hand the HIIT regimen develops a lot of explosive strength and power which in turn requires the body to build muscle. The body here is also trying to achieve efficiency but of a different kind, namely to perform the greatest amount of work in the shortest amount of time and in order to achieve this it has to only lose fat and preserve muscle or even build it. And we all know muscle is active tissue so it keeps burning calories even after the activity has ceased, thereby increasing the body’s basal metabolic rate.  

So, although cardio is a good way to keep healthy and build endurance it’s not the best way to lose fat. The most efficient way to lose fat is by doing quick bouts of strength training followed by short intervals of rest. Try doing quick sprints at full speed for 30 seconds followed by 30 seconds of slow jog or do circuit type training with free weights starting with squats, flowed by dead-lifts, followed by pull ups, followed by bench press and end with shoulder presses. Try to be in the 15 rep range with a minute rest between sets.  Any of these HIIT circuits shouldn’t go over 20-25 minutes. 

So if you are struggling in the gym with fat loss feeling like a hamster on the wheel give one of the HIIT circuits a try. It might be your ticket to jump start your slow metabolism, lose fat and build a firm toned physique!