Muscle Fibre Types
Your muscles contain three distinct types of fibres, each perfectly designed for different sporting activities. Slow twitch (Type 1) fibres are your endurance powerhouses - packed with mitochondria and myoglobin, they appear red due to excellent blood supply and oxygen delivery.
These fibres store high levels of fat and contain oxidative enzymes that break down this fat for energy during aerobic activities. They're slow to fatigue but produce relatively low force, making them ideal for marathon running, cycling tours, or cross-country swimming.
Type 2a fibres (fast oxidative glycolytic) strike a balance between speed and endurance. They contract quickly with high force but fatigue faster than Type 1 fibres. Their pink colour reflects moderate capillary density, and they primarily use the lactic acid system for energy.
Type 2b fibres (fast glycolytic) are your explosive movement specialists. White in colour with limited blood supply, they rely on high PC (phosphocreatine) stores for immediate energy. Perfect for shot put, powerlifting, 100m sprints, or that killer tennis smash - but they fatigue very quickly.
Quick Tip: Most athletes have a genetic mix of all fibre types, but training can enhance the characteristics of each type to suit your sport!
