Cyclists, gravel riders and mountainbikers per say are characterised by having a well rounded endurance capacity and maximal oxygen consumption. This is not only beneficial in relation to performance but also in relation to health!
But what about bone health - how does that comply with cycling!
Recent years' increasing interest in cyclists' bone health has shown, that even young cyclists are at high risk of developing weak bones, which can have serious consequences later in life. One of the primary causes is the fact that cycling is a non-weight bearing activity, thus not stimulating and maintaining bone strength and bone density.
A study by Francisco Javier Martínez-Noguera and colleagues assessed how one season of cycling affected bone health in a group of pro-tour cyclists. Results showed that bone mineral density, bone mineral content and bone area was negatively affected after one season of training and competition. Potentially increasing the risk of negative bone conditions such as osteoporosis later in life.
So why does this degradation of bone strength happen to cyclists?
As mentioned above cycling is a non-weight bearing activity, meaning there is no load or high impact on the bones during training and competition. A really important thing for developing and maintaining healthy and strong bones is to put loads on the bones. This means doing 'high impact activities', which is heavy strength training, plyometrics exercises (different explosive jumps) and running (in particular sprinting), as these exercise modalities are highly important for developing and maintaining strong and healthy bones.
Many cyclists do these kinds of high impact exercises to some extent, but mainly in the off-season and yearly base training. But it is not sufficient just to lift heavy weights, jump and run in the off-season and base training.
To have a beneficial effect these exercise modalities have to be done regularly on a yearly basis. So even in the competitive season a cyclist needs to incorporate a little bit of 'high impact training' to stay strong and healthy. Of course this should be planned around competitions and important training sessions, so it doesn't influence the ability to perform at an optimal level.
Another factor with a potentially negative impact on bone health is the many hours of training combined with insufficient energy intake resulting in an overall low energy availability.
Low Energy Availability (LEA) is a physiological state that occurs when the energy intake is insufficient to meet the combined energy demands from exercise and basic bodily functions. It is a critical condition where an individual’s calorie consumption does not adequately cover both the energy used for physical activity and the energy needed to maintain normal physiological processes, such as hormone production, immune function, and bone health.
One factor that can cause LEA is the high training volumes (+20 hours) often seen in cycling (mainly pro and elite cyclists), which put a high demand on the body's energy stores and the ability to take in enough energy during training and in everyday life.
Another factor is the high focus on body weight in cycling, as performance is highly related to the power to weight ratio (W/kg). Thus, many cyclists tend to eat too little as they want to optimise their power to weight ratio.
The combination of high training volumes and low energy availability will eventually lead to weak bones.
A lot of evidence suggests that young elite cyclists have lower bone mineral density compared to nonelite cyclists or sedentary young adults!
As a young cyclist you might not experience the consequences of an immediate weakening of your bones, but later in life this can become critical for your overall health and functionality. Further weak bones break easier, so having strong bones might save you from a few fractures when crashing.
Besides incorporating high impact training on a yearly basis, it is also important to consider these four nutritional aspects, as they together promote for strong bones:
Energy availability: Make sure the body has enough energy for training, recovery and daily living.
Calcium intake: Meet recommended guidelines for calcium intake, as this is crucial for bone mineralization.
Vitamin D: Vitamin D promotes calcium absorption. Thus, combining calcium with Vitamin D intake is important.
Protein: Adequate protein intake is essential for building and preserving bones.
References:
Hilkens L, Knuiman P, Heijboer M, Kempers R, Jeukendrup AE, Loon LJCV, Dijk JV. Fragile bones of elite cyclists: to treat or not to treat? J Appl Physiol (1985). 2021 Jul 1;131(1):26-28.
Martínez-Noguera FJ, Alcaraz PE, Ortolano-Ríos R, Marín-Pagán C. One Season in Professional Cycling Is Enough to Negatively Affect Bone Health. Nutrients. 2023 Aug 18;15(16):3632.
Mojock CD, Ormsbee MJ, Kim JS, Arjmandi BH, Louw GA, Contreras RJ, Panton LB. Comparisons of Bone Mineral Density Between Recreational and Trained Male Road Cyclists. Clin J Sport Med. 2016 Mar;26(2):152-6.
Oddbjørn Klomsten Andersen, Benjamin Clarsen, Ina Garthe, Morten Mørland, Trine Stensrud - Bone health in elite Norwegian endurance cyclists and runners: a cross-sectional study: BMJ Open Sport & Exercise Medicine 2018