Can You Build Strength and Endurance at the Same Time?

One of the most common questions in hybrid training is: Can I build strength and endurance at the same time — or will one ruin the other?

Here I will answer some of the most common questions using my 10 years of experties coaching in sports and citing what science has to say about training different qualities simultaneously.

What Is Concurrent Training?

Concurrent training means exactly same as hybrid training, just hybrid seems to be more commonly used and recent terms. Hybrid training tho can mean multiple things: training strength and endurance, training two energy systems, training using bodyweight and weights etc. Concurent means simply combining resistance (strength) training with endurance (aerobic) training within the same program — which is the core of being a hybrid athlete as i see it.

But this type of training has historically been said to cause the “interference effect” — the idea that endurance work might reduce strength or muscle growth. Strength training has also been feared to cause bulkines and affect negatively to endurance performance. To some level these are both true but to how much extent? Let’s see what does the science actually say? 

🔑 Key Findings from the Meta-Analysis by Wilson et al. (2012)

1. Yes, you can gain muscle and strength with concurrent training.

Strength-only training produced the highest gains, but concurrent training still resulted in solid improvements:

Strength gains were slightly lower (1.44 vs. 1.76 effect size), wich means that you will get significant strength gains while training endurance at the same time but the progress will be just slower. More about the factors influncing thisa later.

Muscle growth (hypertrophy) was also reduced (0.85 vs. 1.23). He the difference is larger, but still: muscle will grow but just slower. Obviously there is ”glass cealing” with the hypertrophy. Also more about this later.

➡️ Bottom line: Yes, you’ll get results — just not quite as fast as if you did strength-only training.

2. Running interferes more than cycling

Running led to more interference in strength and muscle growth than cycling. Likely due to more muscle damage and longer recovery needed from running. In Cycling there is no excentric work at all! Excentric work means that tha muscle has to break, for example in running when you land on your foot, you have to resist the impact, otherwise you’ll collapse. This is more taxing for the muscle and nervous system than purely concentric work. This was also found in studies done with rowers: Rowing with resistance training resulted same strength and hypertrophy gains as resistance training alone (Bell et al. 1997)

Notable is also that running also resulted better Vo2max gains and lower bodyfat than cycling. Therefore is good to question if running and cycling was done in the equalivent volume? 

➡️ For better strength development, hybrid athletes may prefer mainly cycling and rowing during strength-focused phases. Running should be low volume and short distance. 

Running has stronger interference (negative) effect on strength than cycling. During strength season favor cycling or rowing over running.

3. Splitting strength and endurance on different days works better

Training strength and cardio on separate days or at least 6+ hours apart led to better results than doing both in the same session. “Same-day” training caused slightly more interference, especially if endurance was done before strength. For strength gains it is important that body is well recovered, for endurance it does not seems to be that important. 

➡️ If you’re doing both in one day: sprint or lift in the morning, run later in the day — or vice versa. But if possible, split sessions to different days. 

4. Volume and frequency matter

The more endurance training you do, the more it can interfere with strength gains.

Longer endurance sessions had the biggest negative effect on power output and rate of force development. I have noticed this personally when coaching football(soccer) players, there is barely any proggress in vertical jump during season even when strength and power output are trained due high volume of running. This is why different seasons for endurance and strength are recomended. (see the image below)

➡️ If strength is the priority, keep endurance sessions short.

Volume of endurance training correlates negatively with strength, power and hypertrophy gains.

5. Power is the most affected adaptation

Compared to strength or size, power (explosiveness) took the biggest hit from concurrent training (see the image above). For power I would recommend short season without any endurance training at all, or just 1-2 short sessions done with bike or rower.

➡️ If you're training for power (e.g. sprinting or Olympic lifting), consider cycling endurance phases separately.

6. Interference is mostly in the lower body

Endurance training primarily uses the lower body — and that’s where interference shows up most. That is why upper-body strength and size were less affected. This is why upperbody hypertrophy and strength can be recomended also during endurance season. Personally I like doing high volumes of pull-ups & push ups with my runs.

➡️ This gives more flexibility for combining upper-body lifting with lower-body endurance training.

7. Endurance capacity is not affected

Adding strength work did not harm VO₂max improvements. This is misconception fo some endurance athletes. Just be mindful of not doing extreme leg days that cause excessive soreness.

➡️ You can still build a strong aerobic base while lifting heavy.

8. Concurrent training reduced body fat the most

Programs that combined resistance training with high-intensity endurance led to the greatest fat loss.

➡️ Enough said: with hybrid training you get ripped.

🎯 Practical Tips for Hybrid Athletes

1. Separate sessions by at least 6 hours, or alternate days

2. Use cycling or machines instead of long runs during strength phases

3. Prioritize power separately if it’s a key goal

4. Keep endurance volume moderate if strength/hypertrophy is the goal

5. Track your recovery — don’t underestimate fatigue from high-volume cardio

Reference

Wilson, J. M., Marin, P. J., Rhea, M. R., Wilson, S. M., Loenneke, J. P., & Anderson, J. C. (2012). Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. Journal of Strength and Conditioning Research, 26(8), 2293–2307. https://doi.org/10.1519/JSC.0b013e31823a3e2d

Bell, G, Syrotuik, D, and Socha, T. Effect of strength training and concurrent strength and endurance training on strength, testoster- one, and cortisol. J Strength Cond Res 11: 57–64, 1997.