The Principle of Specificity is about choosing a specific type of exercise to achieve specific fitness goals. Your body will adapt to the things you do, so choose your training to match your goals.
Obviously, your legs will never get stronger or bigger, if you keep skipping leg days. But you also need to consider whether your goal is building strength, improving endurance, or increasing muscle mass. The amount of weight and number of reps and sets are different for each goal.
- If you want to build strength, you need to lift heavy weights. Training with low reps (1-5) and heavier loads teaches your muscles and nervous system to handle more weight. Over time, this will make you stronger.
- If your goal is muscle endurance, like being able to lift lighter weights for longer periods, you need to focus on higher reps (12+). This kind of training helps your muscles resist fatigue and sustain longer efforts, which is useful in endurance sports.
- For muscle growth (hypertrophy), the ideal approach lies in the middle. Moderate weights with moderate reps (usually 8-12) cause your muscles to grow because they stay under tension long enough to trigger growth.
- For sport-specific training, athletes need to practice movements that mimic their sport. For example, sprinters practice explosive movements, while marathon runners engage in long, steady-state cardio.
Each of these adaptations happens because your body responds to the specific demands you place on it. This is why a powerlifter’s training looks very different from a marathon runner’s training — each needs their body to adapt in very different ways.
Balancing specificity with variation
When training lacks specificity, progress may stall because the body isn’t receiving the right stimulus for adaptation. But when your body has adapted to the routine, you may need to change it up to see continued growth and improvement.
Including variety can prevent boredom and reduce injury risk. Incorporating exercises that complement your main training (like mobility work for weightlifters) helps balance the workload on the body.
The principle of specificity explains the importance of training in a way that aligns with your goals. Whether you’re training for strength, muscle growth, endurance, or performance in a specific sport, targeting your workouts to those goals is essential for success.