The real-time stamina feature is designed to help you perform at your best by giving you the motivation and information to push yourself with confidence. It gives you context for interpreting your body's feedback, and you experience the value of this information along your chosen route. With estimates of how much time and distance remain until complete exhaustion, you can predict what you can achieve with your remaining stamina at your current effort.
Stamina describes your ability to deliver a good, high-quality performance. When your stamina runs out, it means you have reached, or are quickly approaching, the point where holding your pace becomes a real struggle. How hard you push affects how quickly your stamina drops during an activity.
The Stamina value (0–100%) reflects how much longer you can keep going at your current level of effort. This metric combines overall fatigue with more temporary limiting factors resulting from anaerobic efforts such as sprints, climbs and surges.
The Potential Stamina value (0–100%) focuses mainly on more general and long-lasting causes of fatigue, such as muscle cell damage, central nervous system fatigue and the effects of depleted carbohydrate stores (glycogen). Activities that leave your potential stamina nearly or completely depleted usually require several days of recovery before it is fully restored.
If you have not fully recovered from your last activity, your stamina level will not be at 100% either.
Your stamina and potential stamina levels should level out during consistent efforts of moderate intensity. Train harder, exceed your lactate threshold (running) or functional threshold power (cycling), and your stamina will drain faster than your actual capabilities. Return to a moderate, sustainable effort and your stamina will gradually recover, moving back towards the level of your actual capabilities as the after-effects of intense anaerobic effort fade.
Calculating stamina
Real-time stamina tracking combines your physiological metrics with a multi-level analysis of your recent and longer-term activity history. This includes examining workout durations, distances covered, training load accumulation and load distribution to find meaningful patterns that reflect fatigue resistance and your personal tolerance for aerobic and anaerobic training.
Although general fitness levels give some insight into your performance capability, sport-specific training adaptation has a major impact on your ability to maintain consistent performance. In other words, running ability does not directly affect cycling ability, and vice versa. That is why real-time stamina estimates during running are based mainly on your running history, and during cycling mainly on your cycling history.
