You're the picture of perfect form and you'd never be caught dead slacking off at the gym. Good. But even health nuts fall prey to these subtle (but serious) exercise mistakes.
1. Eating Too Much Before Your Workout
Check the back of your pre-workout "muscle" bar. Many are loaded with sugar that could make you crash midway through your regimen, says trainer and owner of Results Fitness, Rachel Cosgrove, C.S.C.S. Also, pay attention to how your stomach feels during your workout. Everyone digests differently, and while the "wait 30 minutes to swim" rule isn't hard or fast, if your snack isn't digested when you hop on the treadmill, your body will prioritize fueling your muscles over processing your food and you could be in for a serious stomachache. Cosgrove suggests fueling up for your workouts with a fast-digesting whey-protein shake.
2. Doing the Same Exercises Every Week
We don't care if you like your routine. Every four to six weeks, you have to change it up. "If you're doing the same exercises and weights, you aren't putting an increased demand on your body and are wasting your time," Cosgrove says. Your body adapts to the specific demands (exercises, sets, reps, and resistance) you put on it. "The body is a smart machine, and once it adapts, it starts to conserve energy (a.k.a. calories)," celeb trainer Brett Hoebel, from NBC's The Biggest Loser Season 11 and creator of the 20 Minute Body workout. Luckily, changing things up doesn't mean you have to forgo your favorite exercises. Small changes—like switching your number of sets and reps, adjusting the incline of your bench, or using dumbbells rather than a barbell—can all keep you from hitting a fitness plateau.
3. Resting Too Long Between Sets
We all make fun of the guys who lift a bar twice and then walk around the gym, tapping on their phones for 20 minutes. But you might be surprised just how little rest the typical guy actually needs between sets. Unless you're a bodybuilder and working toward a no-neck, you should never rest for more time than you just worked out, says Hoebel. And most of the time, you don't need to rest any longer than half the time it took you to crank out a set. Rest longer than that and you'll miss out on your workout's calorie burn.
4. Taking Painkillers to Continue Working Out
Pain isn't weakness leaving the body. It's your body telling you something's wrong. And covering up the pain with painkillers (which really just thwart your body's ability to tell it's in pain) can be dangerous, Cosgrove says. Besides inviting you to push too hard through the pain, causing injuries, any meds come with possible complications. In fact, a 2013 studypublished in BMJ Open found that marathoners who took pain meds before a race were five times more likely to experience stomach cramps, cardiovascular problems, gastrointestinal bleeding, blood in the urine, and joint and muscle pain. Painkillers block enzymes that regulate the production of prostaglandins, which let your body feel pain. But researchers believe the chemicals may also protect tissues from the kind of stress your body feels during tough workouts. "If your body is sore, it's telling you to take a day off and rest."
5. Not Working Your Abs Through a Full Range of Motion
A proper crunch doesn't end with your back flat—it extends all the way into a back bend. And exercising only part of that range of motion will reduce the number of muscle fibers that fire, says Hoebel, who recommends performing ab exercises that involve both a full stretch and a contraction. Try performing sit-ups on a stability ball, letting your back and shoulders fall all the way down onto the ball. Move slow and steady so that you feel your abs ache on the way up and down.
6. Stretching Before Working Out
Performing static stretching (think: bend and hold) before a workout can ruin your performance—and results. One recent Journal of Strength and Conditioning Research studyfound that young men who static stretched before performing a squat diminished their strength by 8 percent and lower-body stability by 22 percent, compared to those who performed dynamic stretches pre-squat. Before your next workout, try Cosgrove's favorite dynamic stretch: the bridge . It actively stretches the hip flexors (which are especially tight in desk dwellers) while warming up the lower body and core. Then, after your workout, go ahead and perform your traditional stretches. Most men have tight muscles, especially hamstrings, which stretching can help, she says.