How Long Does It Take Your Body To Feel Fitness Gains After A Workout?

We’d all like to be able to put an exact date on when we’ll feel the effects of a hard session, but unfortunately it’s not that simple.

Our bodies are all unique. The amount of time it takes you to recover from a workout can vary depending on factors like your age, sex, training experience, sleep pattern and genes.

But if we take a look at the science, there are some general timelines that apply to most of us. 

When Do You Reap The Rewards From Training?

The adaptations occur over different time periods for different types of workouts.

Sessions that develop the anaerobic energy systems and focus on building explosive muscle strength typically only take 1-2 days for the adaptations to take place. 

That’s why you can find yourself much stronger very quickly after a strength workout in comparison to endurance-based work, which can take from around 10 days to two weeks for your body to fully recover from.

The reality is that most modes of exercise use a blend of anaerobic and aerobic energy systems. 

Anaerobic Exercise Adaptations

Resistance training and sprinting are types of anaerobic exercises. After a workout involving these types of movements, the brain is able to recruit more muscle fibres.

For such short bursts of activity, our bodies draw energy from the ATP phosphocreatine system which then becomes more efficient.

The nervous system and muscular system begin to work together more effectively, and hypertrophy of muscles is accompanied by a strengthening of connective tissues like tendons. 

Aerobic Exercise Adaptations

With aerobic training like running, cycling or rowing, our cardiovascular system improves. 

The heart can get bigger in size, and its stroke volume - the amount of blood pumped out with each beat - increases meaning more oxygen can be supplied to the working muscles.

Muscles themselves also adapt, becoming able to extract more oxygen. And by looking at muscle cells through microscopes, scientists see a greater number and greater efficiency of mitochondria - the powerhouse of the cell which produces energy. 

Glycogen stores increase too and fat oxidation becomes more efficient so our bodies can draw fuel for longer.