While I was attending Clemson there was a middle aged guy that would consistently (2-3 times per day) show up to join in on cardio classes. After talking with him one day, I came to the conclusion that this guy must eat 10,000 calories of crap every day. Why did I think this? One reason was because he in no way, shape, or form had the type of body I aspired to get (thin legs and arms with a robust mid region). Yet the day we hopped on the bikes in my first, and only, ever spin class, he took me to town. This dude could move!!! The idea that someone could move for that long of a duration, yet have a shape that resembled a food pyramid with legs dumbfounded me for a long time. I chalked it up to nutrition and genes. The one thing I still didn’t understand though, was how bad could his nutrition be? I was 21 years old living off of 99 cent pizzas and Ramon Noodles (I’m not exaggerating when I say I would eat Bojangles 4 times a week and the rest of the week was spent buying shitty food so that I could afford my next Bojangles trip along with my weekend endeavors…). So back to my original question: why didn’t this dude look like a Greek God with his daily regimen of 3 hours of cardio?The more interested I have become in working out and nutrition, the more I have been able to get a grip to my mind-boggling college day question. He didn’t do any resistance training.Without going to in depth and revealing my nerdy side, I am going to quickly explain what was going on. Your body has 2 different fuel systems called the aerobic and anaerobic fuel pathways. The aerobic is fueled by oxygen while the anaerobic is fueled by different cycles in your body. The aerobic side can go on for a very long time (think of going for a walk), while the anaerobic side can only last for a few minutes at the most (think of a 400 m sprint). Which of these two exercises makes you breathe harder? If you’re doing it correctly, the 400 m sprint. Here’s where the cool part comes in! High intensity work (sprints, lifting heavy weight for multiple reps, etc…) makes our breathing increase rapidly. When we breathe heavily we deplete our muscles of oxygen. Once our muscles are depleted of oxygen, it may take a couple days to be able to fill them back up. This is called excess post-exercise oxygen consumption (EPOC). What’s cool about EPOC is that is shoots our metabolism (the amount of calories we burn) up for possibly a couple days!Aerobic Example: walk a mile you burn about 100 calories. Within minutes of finishing your walk, your body is burning the exact same amount of calories it was before your walk.Anaerobic Example: 16 sprints of 100 m (this is a mile). You burn about 100 calories. Your body continues burning calories at a higher rate for possibly 2 more days.In each example, the calories burnt during the workout were equal, but the calories burnt post-workout are much different.So now comes in the strength training. Muscles require oxygen to work. The more muscles you have, the heavier you can lift. The heavier you lift, the more oxygen is required. The more oxygen required, the higher you boost your metabolism… You see the trend?While it is not good for your body to go 100% all out every day, it is good for you to boost your intensity. Remember, intensity is something you can only do for a very short time (1-3 minutes). Running a marathon feels intense, but takes much longer than 1-3 minutes. If you are someone who believes it’s not working out unless you’re trying to kill yourself on a treadmill for 45 minutes how about taking a step back, look to see if you’re achieving your goals, and then go pick up some freaking weight. Mix your days up between cardio and weights and see what happens.A couple of things to leave you with:1. The #1 indicator of how someone will age is not cardiovascular shape, flexibility, or balance as many people would believe. It is grip strength. So go pick up some weight!2. Don’t go home and breathe as fast and as hard as you can while sitting on the couch and think you will get shredded, you’ll pass out. The breathing must be driven by muscle contraction and elevated metabolic demands.Everyone wants to look good naked. This is best done with a mix of both weight lifting and cardio. Focusing on one only is not the best solution!Travis KreuzbergerCrossFit Level One TrainerPrecision Nutrition Certified Coach