The weight room should be an athlete’s second home during the off-season. A well-structured strength and conditioning plan can help an athlete build strength, power, endurance and durability that will pay massive dividends once the season arrives.

If you’re reading STACK, you already know this. But did you know that a handful of costly weight room mistakes can sabotage your efforts and even decrease your athleticism?

Here’s a list of 10 common mistakes athletes make while training. Are you making any of them?

1. Skipping the Warm-Up

One of the most costly mistakes often happens as soon as athletes walk into the gym. If you skip your warm-up, you miss out on an opportunity to improve mobility and flexibility, and you increase your chance of injury.

A proper warm-up should:

• Raise the body’s core temperature
• Mobilize and stabilize joints such the hips, shoulders and ankles
• Preview movement patterns you will use in your workout (e.g.,  Squats, Lunges, etc.)

Don’t be the guy or gal who does a few arm swings and toe touches and thinks you’re ready to go. Do yourself a favor and take 8 to 10 minutes to perform a thorough warm-up. That means foam rolling, mobility drills and a few light sets of your first strength exercise to get your body ready.

RELATED: The 7-Minute High-Intensity Dynamic Warm-Up

2. Performing Too Many Isolation Exercises

Nearly every sport requires fluid, full-body movements. So why on earth would you spend time in the gym working one body part at a time?

Sure, big biceps and shapely calves look good on the beach, but if it’s athleticism you’re after, you need to ditch the majority of your isolation exercises.

Instead, pick multi-joint strength movements like Squats, Deadlifts and Push-ups, along with powerful exercises like Jumps, Sprints and Throws. In fact, put them together to build unparalleled explosiveness with post-activation potentiation.

3. Never Deloading

Many athletes pride themselves on pushing to the brink of exhaustion, but always teetering on that line can halt your progress. Every once in awhile, you need to take a step back to take two steps forward.

Deloading is a planned training period during which you don’t work quite as hard, thus allowing your body and mind to recover so you can keep getting stronger. If you’re training hard at least four days per week, you should take a week-long deload every four to eight weeks to recharge your batteries.

4. Training to Failure Too Often

Your workouts should build you up, not break you down. There’s no faster way to leave yourself feeling broken down than training to failure too often.

Luckily, you don’t have to train to failure at all to get bigger and stronger. As a general guideline, always leave one or two good reps in the tank at the end of each set. You’ll recover faster and still make progress.

A surefire way to avoid training to failure is to pick the right number of sets and reps for each exercise. Big, heavy exercises like Squats and Deadlifts lend themselves to fewer reps and more sets, while lighter exercises like Push-Ups and Pull-Ups work best with more reps and fewer sets.

5. Wearing Improper Footwear

Did you know that what you wear on your feet can have a huge impact on how you move? Your workout footwear can greatly enhance—or reduce—the effectiveness of your exercises.

For example, wearing running shoes to Squat or Deadlift is a common mistake. The soles of running shoes are cushioned to reduce impact while jogging. But when you’re lifting a heavy barbell, you want a solid heel so you can produce force into the ground. The squishy soles of a running shoe reduce stability and limit how well your legs produce force. Instead, opt for a flat-soled shoe (like the New Balance Minimus) or a heel-elevated shoe with a hard sole (like an Olympic lifting shoe).

6. Sacrificing Form for Weight on the Bar

As fun as it is to throw around heavy weight, athletes need to remember that their main competition is on the field, not in the weight room.

Lifting heavy weight is one of the fastest and most effective ways to become a better athlete, but never at the expense of proper form. If you get hurt in the gym, all your efforts were for nothing.

It turns out that some of the best exercises for athletes (Squats, Deadlifts, Cleans, Snatches, etc.) are some of the most risky, because they apply shear and compressive forces to the spine. That said, take the time to master the technique before loading these exercises with heavy weight. Train under the guidance of a certified coach or trainer whenever possible, and use spotters when appropriate.

7. Doing Too Much Cardio

Most team sports require athletes to run lots of short sprints, followed by periods of slow jogging or walking. If that’s the case, why do so many athletes spend hours each week running long distances?

Cardiovascular endurance is certainly important for athletes, but sport-specific endurance should be the number 1 priority. The type of running you do for your sport should make up the bulk of your conditioning.

Baseball player? Run short, intense sprints with long rest periods. Soccer player? Run longer distances with shorter rest periods. Football player? Run based on your position and keep the 40-second play clock as your rest.

8. Not Doing Enough Cardio

On the other hand, doing no cardio at all is a bad idea. Even though most athletes need strength and power more than they need endurance, it’s a costly mistake to ignore aerobic conditioning entirely.

That’s because all recovery is aerobic in nature. Your oxidative energy system is responsible for regenerating ATP, the body’s main energy source. Intense exercise requires lots of ATP, and if your oxidative system is poorly developed, you’ll take a long time to recover between plays.

There are lots of ways to do cardio besides jogging. Check out this article by Cressey Sports Performance coach Miguel Aragoncillo for ways to improve your aerobic conditioning.

9. Neglecting Unilateral Exercises

Athletes make their living on one leg at a time. Sprinting, jumping, throwing and swinging place the body in unique positions that require each limb to act independently, so it makes sense to use single-leg and single-arm exercises in the weight room.

The Squat and Bench Press are fantastic strength movements, but make sure you follow them up with unilateral exercises like Lunges and Rows to reflect the one-sided nature of your sport.

10. Not Putting Your Phone Away

A lack of focus will derail any athlete’s workout, and nothing does that faster than a smartphone.

When you walk through the gym doors, your only priority for the next 60 to 90 minutes is getting better. Nothing on Facebook or Instagram will help you lift more weight or get more explosive, so put the phone away.

To avoid distractions, use a notebook instead of your phone to track your workouts. If you use your phone to listen to music, arrange a playlist ahead of time so you’re not fidgeting with your phone mid-workout to find a song you like.

[cf]skyword_tracking_tag[/cf]