5 Fitness Mistakes That Impact Men’s Health

“Train smarter, not harder” isn’t just a catchphrase, but a principle all guys should follow to keep their workouts from causing health issues—because, yes, that can happen. 

“Having a regular exercise routine offers benefits that show up quickly and can last a lifetime,” says certified strength and conditioning coach Jake Harcoff, C.S.C.S., head coach and owner of AIM Athletic. In the short term, consistent training can support muscle growth and maintenance, boost energy, improve sleep, up-level body composition, and relieve stress. Over time, sticking to a routine can lead to stronger bones, better heart health, and even extend your life and health span. 

Still, there are times when an imbalanced or overzealous workout regimen can backfire, causing more harm to a guy than good. Ahead, a closer look at five common fitness mistakes that can lead to men’s health issues, plus tips for addressing them. 

• ABOUT OUR EXPERTS: Jake Harcoff, C.S.C.S., is a certified strength and conditioning coach and owner of AIM Athletic. Jerry Bailey, M.S., D.C., is a chiropractor, functional medicine practitioner, and certified nutritionist with Lakeside Holistic Health in Coeur d’Alene, ID. Jake Merges, C.S.C.S., is a certified strength and conditioning specialist and personal trainer with PRO Club in Seattle.

Fitness Mistake 1: You’re Too Hype on HIIT

High-intensity interval training can be an effective tool for building cardiovascular fitness, with research showing it can improve aerobic capacity and potentially enhance heart health. “However, doing too much high-intensity interval training has downsides,” says Harcoff. 

Whether it’s a CrossFit workout of the day, a bootcamp class, or an at-home workout video, HIIT-style workouts cause a temporary spike in levels of the stress hormone cortisol, explains Harcoff. This short-term rise is normal and beneficial, as it gives your body an energy boost that allows you to power through a tough session. But—and this is important—your cortisol levels should drop down soon after you cool down, he says. 

The thing is, repeated HIIT sessions day after day, week after week, can interfere with the body’s ability to lower cortisol levels after exercise, keeping them elevated for longer than they should be, says Harcoff. This stress piles on top of the other stressors in your life (i.e., work deadlines, family obligations, poor sleep), leaving your system in a near-constant state of fight-or-flight. 

The downstream effects here can be significant. “Chronically high cortisol levels can drag down testosterone, mess with sleep, and even lead to fat gain,” says functional medicine practitioner and certified nutritionist Jerry Bailey, M.S., D.C., a health provider and chiropractor with Lakeside Holistic Health in Coeur d’Alene, ID. Considering that tanking testosterone alone can contribute to low sex drive, hair loss, fatigue, and moodiness, that’s probably not a road you want to go down.

The Fix

HIIT isn’t the enemy, but it shouldn’t be the mainstay of your training. “Mixing in lower intensity training, mobility work, or simply taking more rest days can go a long way in restoring recovery and ensuring HIIT sessions remain effective instead of undermining your goals,” says Harcoff.

Read More: 6 Science-Backed Ways To Lower Cortisol

If your goal is to build muscle (it probably should be), Harcoff recommends following a strength regimen that implements the progressive overload principle. You should also limit HIIT-style workouts to two days per week with rest days between sessions. This balanced approach will help your body build muscle and maintain hormonal balance, keeping your training sustainable throughout your lifespan, he says. 

Fitness Mistake 2: You’re Constantly In A Cut 

No question that having excess fat on your body can be unhealthy. In fact, the National Institute of Diabetes and Digestive and Kidney Diseases reports that carrying excess fat is a risk factor for health conditions like type 2 diabetes, heart disease, hypertension, stroke, and even various cancers. 

However, swinging too far in the other direction can be a problem, too. “Having too little fat can also be detrimental,” according to certified strength and conditioning specialist Jake Merges, C.S.C.S., a personal trainer with PRO Club in Seattle. Body fat is essential for hormone production, brain function, and nutrient metabolism. If your body fat dips too low, you may experience disrupted testosterone production, energy, and mood. According to the American Council on Exercise, less than six percent body fat is the danger zone for men. 

Most men won’t achieve this level of lean from exercise alone, as it typically requires precise calorie and macronutrient management in the kitchen, Merges says. If you’re into bodybuilding or hyper-focused on your fitness and physique, short-term cuts that help you drop body fat may make sense for sport. However, staying in the calorie deficit required to get this lean for too long can suppress metabolism, elevate cortisol, and make it harder for the body to maintain muscle mass, he says. 

The Fix

If your goal is to get leaner, pair your nutrient intake with consistent strength training and adequate sleep, rather than living in a perpetual cut. Most active guys thrive around 10 to 20 percent body fat, according to the American College of Sports Medicine. Sticking to this Goldilocks range will enable you to achieve overall health. 

Fitness Mistake 3: Cardio Is Your Ruler

Running an ultramarathon or completing a triathlon may give you bragging rights—and plenty of Strava kudos—but “doing excessive amounts of cardio and endurance work can take a real toll on the body,” according to Harcoff. 

For starters, only doing one type of exercise over and over again often leads to muscle imbalances, he says. Running, for example, tends to develop the lower body while neglecting the upper body, whereas cycling emphasizes the quadriceps and hip flexors to the detriment of the posterior chain. Over time, these imbalances can alter posture, restrict mobility, and increase the risk of injury. 

High-volume cardio can also be tough on your joints and connective tissues. Running, in particular, sends forces equal to two to three times your body weight through your knees, hips, and ankles with every stride, says Harcoff. Over time, this repetitive pounding can put a lot of strain on the cartilage and joints in your lower body, even leading to overuse injuries such as tendinitis, plantar fasciitis, and stress fractures. 

Additionally, “there is some truth to the belief that cardio interferes with muscle growth,” says Harcoff. Known as the interference effect, the gist is that the demands of endurance training compete with the adaptations your body needs to get stronger. “You can see this by comparing the body of a marathon runner to that of a sprinter; they emphasize different muscle fiber types,” he explains. With that, while endurance athletes may develop cardiovascular capacity and efficient slow-twitch muscle fibers, they may experience a loss of muscle mass, which can limit strength and even impact metabolic health, since muscle is a highly active tissue, he says. 

Research has also found that excess endurance training can lead to lower resting testosterone levels, which can make it harder to build or maintain muscle mass and recover fully between sessions.

The Fix

Don’t toss your running sneakers just yet. “Cardiovascular capacity training has great benefits,” says Bailey. “The right amount of cardio improves circulation, helps recovery, strengthens the heart, and plays a huge role in longevity.” 

Finding the right balance of cardio and lifting gives you the best of both worlds. That’s why Harcoff recommends Cardio Kings update their workout regimen to include both. The CDC recommends strength training at least twice a week to maintain muscle mass and support solid T levels and overall health. Exactly how much cardio your body can handle before it becomes a detriment depends on factors such as your recovery (sleep, nutrition, stress) protocols, training age, and exercise intensity. Talk to a trainer or other expert about your specific habits and goals for more tailored advice. 

Read More: How To Adjust Your Strength Training Game As You Age

If you’re training for a specific event, Harcoff recommends structuring your sessions around your primary goal. “Do the exercise that best correlates with your goals first,” he says. So, if you want to improve your speed or endurance, do your cardio workout, then hit your lifts afterward or a few hours later, he says. 

Fitness Mistake 4: You’re Skipping Compound Lifts 

Bicep curls, leg extensions, and skull crushers may have a place in a well-rounded workout routine. But, “focusing too much on isolation exercises while skipping compound lifts can limit the overall benefit you get from training,” says Harcoff. 

Isolation lifts target a single muscle group at a time, which can be beneficial for changing your aesthetic or fixing muscle imbalances. But, “compound movements like squats, deadlifts, and overhead presses recruit more muscle groups throughout the body,” Harcoff says. This allows you to move heavier loads, which stimulates greater production of testosterone and growth hormone, boosts metabolism, and leads to bigger increases in strength. Without them, guys are more likely to lose strength and muscle mass as they age, he warns. 

Compound exercises also train the functional movement patterns that support daily activities, like lifting groceries, climbing stairs, or playing with your kids. With that, doing isolation over compound lifts can lead to decreased independence with age. 

“Targeting multiple muscles at once with compound movements can also make your workouts more efficient,” Harcoff notes. “You’ll get more benefit in less time.”

The Fix

There’s no need to ditch isolation exercisers altogether. “Isolation work has its place for targeting weak points in your bigger lifts,” he says. Because isolation moves are typically less taxing on muscles and the central nervous system, they can be useful for recovery days or accessory work after your main lifts, he says. 

However, compound lifts should be the star of the show. Harcoff recommends focusing on one or two compound lifts per training session, then sprinkling isolation movements that target any underdeveloped muscle groups into the second half of your workout. 

Fitness Mistake 5: You’re Overtraining and Under-fueling 

Crushing back-to-back workouts might make you feel like a beast in the gym. But if you’re not giving your body the time and fuel it needs to recover, you could slow progress—and even do your overall health a disservice. 

Without adequate nutrients and calories, your body doesn’t have the energy or building blocks it needs to repair exercise-induced damage. “If you are constantly underfueling or eating an extremely restricted diet, it can lead to overtraining syndrome,” says exercise physiologist and board-certified sports dietitian Jason Machowsky, R.D., C.S.C.S.

Known to impact almost every system in the body, “overtraining shows up as constant fatigue, nagging injuries, restless sleep, or even loss of motivation,” says Bailey. Extreme cases have even been linked with higher resting heart rates and elevated blood pressure, which can lead to chronic health issues. The Society for Endocrinology also reports that overtraining can lead to hormone imbalances, including low testosterone. 

The Fix

Don’t let fears of overtraining keep you from your exercise routine. “Most average gym goers don’t push hard enough to reach a point that true overtraining becomes an issue,” says Harcoff. “In most cases, your exercise routine will improve overall health and well-being.”

However, if you train at high intensities and volumes, make sure your non-gym time supports your efforts. Aiming for seven to nine hours of quality sleep per night supports muscle repair and hormone balance, while eating nutrient-dense foods (and filling the gaps with supplements like protein powders) ensures you have the energy you need to work out and recover, Harcoff says. 

He also recommends scheduling at least one or two rest or active recovery days per week to give your nervous system, joints, and muscle meat time to repair and reset.