Skip to main content

The question: I swam and walked a lot all summer. I love doing both, but I just went back to the gym and I can hardly lift any weights. I was expecting to be stronger and more fit from being active all summer, but I seem to have gotten weaker. What gives?

The answer: The body is highly adaptive – almost breathtakingly so. Unfortunately, the adaptations are very specific to the stimuli you give it (this is known as the principle of specificity).

Take me as an example: As a triathlete, my body has learned to endure hours of running and biking. But all the cardio training that I do means I have developed muscular and cardiovascular endurance, and not muscular strength. When I lift weight with colleagues who prioritize strength training, I am a weakling by comparison. That said, it is not pretty when they try running with me.

Swimming and walking strengthened your cardiovascular system and gave you muscular endurance.

The good news is, your heart and lungs say thank you. The bad news is, currently you are more likely able to lift lighter weights for multiple reps (this is muscular endurance) than heavy weights for fewer reps. This is because over the summer, your body adapted to all the swimming and walking; it learned how to work at a relatively low capacity for a long time.

Don't get discouraged. You didn't waste your summer. You would have lost even more strength if you had simply relaxed on a deck chair! More importantly, staying active, in any capacity, is always something to be proud of. Plus, you enjoy swimming and walking. Finding activities you love is a vital component of staying active long-term. The more you enjoy something, the more likely you are to repeat the activity.

Maintaining an active lifestyle is all about forming positive habits, which you were able to do all summer. Going to the gym and building back your strength should seem like a piece of cake as you will crave the activity.

Trainer's tip: Progress gradually. It is probably tempting to try and lift the weights you used before your summer hiatus. Try and resist that urge, because progressing too quickly usually leads to injuries.

Kathleen Trotter has been a personal trainer and Pilates equipment specialist for 10 years. Her website is