Cyclists build up great fitness levels for their cycle specific muscles but running is a high impact sport with every step.
When any person who starts a training routine, as their fitness improves the Muscles Ligaments Tendons and Joints all develop at a different rate. This is why fit cyclist often get injured running because their fitness is greater than their running muslces.
There are many physiological differences between running and cycling for single sport athletes
The cyclists who run to the marathon runner who cycles to the triathlete who wants to be proficient at both.
It is important to understand the differences between cycling and running.
Experienced triathletes tend not have different V02 max values in cycling and running.
V02 max, Blood flow, Maximum Heart rate & muscle fatigue can be different for each athlete when they train in a different discipline.
From my experience most of the athlete is have worked with get more physiological fitness benefit from running to cycling rather than cycling to running.
Heart rate values for maximal and submaxiumal is different and usually higher in a well developed triathlete who cycles and runs compared to a single sport specialist.
Ventilation is more impaired while cycling than running. Finding the best cadence for you will improve performance and so will strides per minute while running, ignore what every one else is doing.
If you are a cyclist with good cardio fitness then your running specific muscles are your limiting factor because
For people who travel a lot running is an easy sport to do, no bike or the hotel swimming pool is tiny or public pool is closed or too busy.
It’s easy to fit in a run when you are free. You can time your run to the second with and out and back run
Correct running shoes and running kit and you can run almost anywhere.
Choosing the right shoes for your running style will prevent or reduce the chance of injuries. Is your running gait Pronation (outward roll) Supination (inward roll) or do you run with a neutral style.
Some coaches believe say can get the same fitness benefit from a 45 minute run compared to a 90 minute cycle. Both disciplines and it all depends on the percentage of heart rate. Your maximum heart rate running is likely to be higher than cycling by 4>10 beats per minute.
Comparisons can be made between the time spent runnings instead of cycling
Because cyclist who are unable to cycle run instead and they can compare the training completed to the loss or fitness maintained when they resume back on the bike Muscle contractions are different for running compared to cycling.
Cyclist has no muscular conditioning for running even if they ran last winter.
I have competed for 30 seasons in triathlon and coached triathletes for more than 15 years.
Cyclist will benefit from Easy to medium running, any harder and it can develop running specific muscle groups which can cause problems and can hinder cycling performance in the future.
When it is icy running off road is a better alternative than nothing or risk crashing damaging you and your bike.
Each cyclist will be able to cope with different amounts of running. The biggest cause of running injuries is because of running on the same surface and becoming a single dimensional runner, run off road when possible. Avoid marbled surfaces found by sea fronts that are the most unforgiving surfaces and brutal on the calf muscles of every runner let alone cyclists.
During running eccentric muscle contractions occur (The muscle lengthens as you shorten it). Every single running stride you are asking the muscle to contract and stretch. This is the reason why runners especially marathon runners quads hurt walking down stairs but not going up stairs after a race or hard run.
In a well conditioned runner osscialtion (micro tears in the muscles occur) so your muscles joints and ligaments give up before your energy levels
The cycling muscle shortens as it contracts known as concentric contractions, the complete opposite to running.
Because cycling is a low impact sport (well most of the time) you can go on for longer so correct energy levels & a good hydration strategy is your limiting factor
To be good at cycling you must cycle train specific and to be a competent runner then run.
Training in a different sport is a great way to refresh the mind or when you can’t do your favourite sport and it will help with fitness.
Cyclist should consider a run walk strategy (Run 4 mins walk 2 minutes Progress to 5 minutes run 1 minute walk)
Benefits you keep good biomechanics and will be much easier on the muscles providing you do not.
Motto Take it easy when taking up a new sport. Fitness is relative.