The Truth about Strength Training for Endurance Athletes

As an endurance athlete, whether you’re a runner, cyclist, swimmer, or participating in any sport requiring sustained effort, your primary focus is typically on building stamina, cardiovascular fitness, and muscular endurance via high training volume. But there’s an often-overlooked element that can significantly improve your performance: strength training.

At this point, you’ve likely heard of the principal benefits of strength training including greater bone density, increased power, and reduced risk of injury. However, among endurance athletes, there are still several misconceptions out there when it comes to strength training that need to be dispelled. Let’s dig in.

 

Myth #1: Strength Training Will Make Me Bulky

Many endurance athletes shy away from strength workouts, fearing that lifting weights will make them “too bulky.” 

This is a real fear, especially in sports like cycling where an athlete’s power-to-weight ratio is king. Particularly, this fear shows up among female athletes, discouraging them from picking up the dumbbells and missing out on major performance gains.

Strength Training Doesn’t Make Women Bulky – Here’s Why

Resistance training increases muscle density, which can help you look more sculpted and defined—but it won’t turn you into a bodybuilder unless you are specifically training to do so.

Realistically, female athletes might gain 500 grams (or ~1 pound) of muscle mass in a 3-6 month period of dedicated strength training. Surprisingly, this would be considered significant progress.

Diet Plays a Major Role in Muscle Growth

While lifting weights is important for building muscle, diet is equally crucial. To develop significant muscle mass (i.e. to get “bulky”), a person needs to consume a calorie surplus along with a high protein intake to support muscle hypertrophy. Women, on the other hand, typically don’t eat enough to trigger this level of growth.

Even with a significant energy surplus from diet, females tend to max out at lean muscle mass gains of about 3 kilograms (~6.6 lbs) per year. 

According to a 2016 research study, competitive female cyclists with greater lean muscle mass in their lower body tended to have 4% to 9% higher maximum average power per kilogram of body weight. That means that strength training resulted in a higher power-to-weight ratio (watts per kilogram) over 1 sec to 10 min power compared to non-strength trained elite cyclists.

Conversely, men tend to max out at 1 kilogram of muscle gain per month and average about 6 to 8 kilograms per year.  That said, according to a 2021 study, both men and women who engaged in concurrent strength and endurance training similarly improved %VO2max, enhanced cycling economy and increased their ability to generate high power output for short periods of time compared to athletes who simply performed endurance training alone. 

Undoubtedly, resistance training can be tolerated, promote adaptations and directly improve performance no matter your gender.

 

MYTH #2: Strength training won’t make a big enough impact on my performance

Here’s how strength training improves endurance performance: 

• Lifts Lactate Threshold Power by 3 to 5 percent 
• Boosts max force output
• Improves efficiency and running/cycling economy, particularly among female athletes
• Increases lean muscle mass and muscle density, enabling muscles to be more resistant to fatigue
• Contributes to superior performance in a fatigued state, including a lower heart rate after 3 hours of training and a lower percentage of VO2max utilization
• For cyclists, leads to earlier peak torque during the pedal stroke (resulting in a longer relaxation phase and increased blood flow to working muscles)
• Enhances muscle endurance by changing muscle fiber strength — Type 1 fibers (slow twitch) become stronger, and Type 2x (fast twitch, ‘pure power’) fibers transform down to the more efficient Type 2a (fast-twitch, ‘muscle endurance’) fibers.

In short, incorporating strength training into an endurance training plan is an excellent way to maximize endurance performance.

 

MYTH #3: I don’t have time for strength training, especially during competition season

Combining endurance training with strength training yields the biggest gains for performance

Even just 10 weeks of heavy strength training yields positive results for athletes who can only spend a limited amount of time per year in the gym.

That said, strength-maintenance training is essential to retain the strength gains during competition season. 

How often do cyclists, runners and triathletes need to hit the gym?

Studies show that just one heavy strength session every 7-10 days can help maintain the benefits of an 8-10 week off-season strength training block. If you’d like to get the maximum adaptations from off-season strength training, it’s best to aim for 12 to 15 weeks of a dedicated resistance training program.

For in-season maintenance, one strength training session per week is a realistic addition to any endurance athlete’s periodized training regimen. Additionally, be sure to include multiple exercises for the target muscle group and lift heavy, about 80 to 85 percent of your 1-rep max. I recommend incorporating the strength session at the end of a training block just before a rest day or easy day to limit any potential fatigue.

The Bottom Line

Strength training is the key to endurance athlete success. Without a doubt, incorporating strength training into your routine is not only manageable with a well-crafted plan, but it will also tangibly boost endurance performance, improve lean muscle quality without necessarily adding bulk, and help you avoid injuries in the long run.

Looking for more?

Check out my videos providing strength workouts for endurance athletes! A few of my favorite functional strength exercises include the: Single leg Romanian deadlift, the monster walk, and the single leg glute bridge. I’ve also created videos on mobility for endurance training.

Interested in transforming your performance with a specific strength training plan for runners and cyclists? Send me a message to get started!

 

Sources:

Vikmoen, O et al. “Strength training improves cycling performance, fractional utilization of VO2max and cycling economy in female cyclists.” Scandinavian journal of medicine & science in sports vol. 26,4 (2016): 384-96. doi:10.1111/sms.12468

Mujika, Iñigo & Rønnestad, Bent & Martin, David. “Effects of Increased Muscle Strength and Muscle Mass on Endurance-Cycling Performance.” International Journal of Sports Physiology and Performance. 11. (2016) 283-289. 10.1123/IJSPP.2015-0405.

Vikmoen, Olav, and Bent R Rønnestad. “A Comparison of the Effect of Strength Training on Cycling Performance between Men and Women.” Journal of functional morphology and kinesiology vol. 6,1 29. 17 Mar. (2021) doi:10.3390/jfmk6010029

Rønnestad, Bent R et al. “10 weeks of heavy strength training improves performance-related measurements in elite cyclists.” Journal of sports sciences vol. 35,14 (2017): 1435-1441. doi:10.1080/02640414.2016.1215499

Ronnestad, Bent. “Concurrent Strength and Aerobic Training” Coach Diploma Program, UCI World Cycling Center, Oct. 2022, Switzerland, Aigle.