Lots of people have lots of questions about exercise.
And there are many place people look for answers. Once in a while I’ll jump onto one of those site and offer reasonable advice. Two sites with lots of exercise questions and answers are Quora and Sharecare. I’ve been answering questions on both since 2012. Here are a few of the answers I gave to their visitors’ questions.
Which formula is more accurate for calculating “Fat Burning Zone” ? Are they really necessary?
There really is no such thing as a “fat burning zone”. Yes, in some of your heart rate zones your primary fuel source will be fat. The mistake is in thinking that continually working in that zone is going to continue to burn fat effectively.
There is a training principle called Specific Adaptation to Imposed Demands. What that means is no matter what demands your put on your body, if you continually put the same demands on your body, your body will get used to having to take that demand and will become more efficient at handling that demand.
What that means for your “fat burning zone” is that if you’re continually working at 50%-60% of your maximum heart rate, the theoretical “fat burning zone”, your body will get used to you working at that heart rate and will become better at handling it, meaning it’ll become worse at burning fat. Now this is actually a good thing. Without the SAID principle, our bodies would never get better at any form of physical effort: you’d never be able to get stronger, you’d never be able to run any further, you’d never be able to swim more laps, you’d never be able to cycle any faster.
But if your primary goal is fat loss, it’s inefficient to constantly work at the same intensity level. You need to mix up your workouts, specifically by mixing up which heart rate zones you’re working through. The is best done by using Heart Rate Zone based Interval Training.
Is it bad to have a “random approach” at the gym by doing cardio some days and weights other days with no long-term goal for either?
No, it’s not “bad” at all. Like everyone else here has said, at least you’re there and doing something.
But is it optimal? Nope.
Just think about anything great that has ever been accomplished by people. It got accomplished because they had a goal. You’re best served by having a plan for both your cardio and your weight training. So the first thing to do is to ask yourself “Why am I doing this? Why am I at the gym? What am I trying to accomplish and why?” This posting I wrote might help clarify how to think of the answer: Do the right exercises for what you like to do outside the gym.
When you see these TV commercials for home exercise programs on DVD that talk about “muscle confusion”, they’re not really “random” workouts, if they were, how would you be able to make a DVD showing people how to do it? Even within a well formatted training program that looks at meso-cycles and micro-cycles, you’ll have variation in the selection of variables of your workouts. You’ll vary the actual exercises even within the same muscle group, you’ll vary the weight, you’ll vary the repetitions, you’ll vary the contraction spectrum (time it takes to complete a single repetition)… etc.
If you’re aware of chaos theory, there is order within the chaos and chaos within the order. Same thing goes for fitness.
How long should a teen hold each stretch when stretching?
Your age is irrelevant when it comes to stretching. The way different stretches affect the muscles, tendons and the nervous system is the same.
What you need to know is why you’re stretching and when in your exercise cycle you’re stretching.
If you’re stretching to warm up, you want to do active stretching, where you hold the stretch for 3-4 seconds and repeat 6-8 times. This prepares your body for activity, begins to increase your core temperature and increases blood flow to your tissues.
If you’re done exercising and want to affect a permanent change in the length of your muscles, you’ll do the static stretching, when you’ll hold the stretch for 25-30 seconds and repeat 2 or 3 times. You don’t want to do static stretching before exercise, as you’re essentially asking the muscle to shut off, which of course will decrease performance and potentially open you up to injury.
The exception to that rule is when you’re working to correct a muscular imbalance. Suppose you and your trainer have found that your right hamstring is considerably tighter than your left. You could do static stretches on the right hamstring at the beginning of the workout, but importantly, you’d then re-integrate the muscle by performing symmetrical active stretching or unloaded motions like squats and lunges. By doing these active stretches or motions, you re-awaken the muscle, getting it ready for more vigorous activity.
You can use this site for exercise questions and answers too.
I highly encourage you to use any pages on this site as a forum to ask any exercise related question you may have. I’ll answer any question you pose in the comments of any page. Is there a question I haven’t covered anywhere? Put it into the comments section below.