What causes muscle cramps during exercise? Athletes and coaches may want to look at the playing surface

For athletes across all sports, few experiences are as agonizing as being forced to leave competition with a sudden muscle cramp. These painful, uncontrolled spasms – formally known as exercise-associated muscle cramps – have frustrated athletes, coaches and researchers for decades.

Scientists have traditionally attributed exercise-induced cramps to dehydration or electrolyte imbalances. However, this theory left unanswered questions. For example, many well-hydrated athletes experience cramps, while others competing in hot, humid conditions remain unaffected.

A growing body of research is challenging this explanation, pointing instead to the playing surface as a critical factor.

In my work as a sports scientist, I study how different variables affect athletic performance. Work from my team has found that specific qualities of playing surfaces can lead to early neuromuscular fatigue and unexpected muscle cramps.

Muscle cramps and playing surfaces

As muscles fatigue, the normal balance between signals in the nervous system that direct muscles to contract and relax become disrupted. Muscle spindles, which sense stretch, increase their firing rate. Meanwhile, inhibitory feedback from Golgi tendon organs – a part of the nervous system at the intersection of muscle fibers and tendons – declines.

In other words, muscles are getting mixed signals about whether to contract or relax. The result is excessive activation of motor neurons that stimulate muscle fibers into a sustained, involuntary contraction – a cramp.

Recent studies suggest that competing on surfaces with unfamiliar mechanical properties – such as stiffness and elasticity – can accelerate neuromuscular fatigue. Surfaces alter the mechanics of your muscles and joints. If your neuromuscular system is not accustomed to these demands, fatigue can prematurely set in and create the conditions for cramping.

In one study, my team and I found a 13% difference in muscle activity among runners performing on fields of varying stiffness and elasticity. Another study from my team found a 50% difference in hamstring activity among athletes performing identical drills on different types of turf.

Beyond sports-specific performance metrics, biomechanics research has long shown that altering the properties of playing surfaces changes muscle stiffness, joint loading and range of motion. These variables directly affect fatigue. Muscles crossing multiple joints such as the hamstrings appear especially vulnerable to variations in playing surfaces, given their central role in sprinting and cutting.

Preventing cramps during exercise

If playing surfaces influence fatigue, then managing how they interact with players could help prevent cramps.

Researchers have proposed developing regional databases cataloging the mechanical characteristics of competition surfaces for sports such as tennis. With this data, coaches and sports organizations could tailor training environments to mimic competitive conditions, reducing the shock of unfamiliar surfaces. It’s not necessarily the inherent properties of the surface that causes cramping, but rather how similar or different they are from what an athlete is used to.

Consider a soccer team that practices on a soft surface but competes on a more stiff surface. Without preparation, the shift in how their muscles will be used may lead to premature fatigue and cramps during competition. By incorporating drills that replicate how athletes’ muscles will be activated on competition turf could help the team better prepare for game conditions.

Similarly, a basketball team accustomed to new hardwood may benefit from training sessions on worn or cushioned courts that simulate upcoming away venues.

The key is systematic exposure. Conditioning on surfaces that replicate competitive demands acclimatizes the neuromuscular system, lowering fatigue risk and potentially reducing the risk of cramps.

Toward a holistic approach to cramps

Hydration and nutrition remain essential for performance. But accounting for conditioning, footwear traction and adaptation to different playing surfaces could help sports medicine move toward a more complete solution to exercise-associated muscle cramps.

With continued research and technology development, cramps may no longer need to be a frustrating inevitability. Instead, athletes and coaches could anticipate them, adjust training to match surface demands, and take steps to prevent them before they derail performance.

The future of cramp prevention may lie in real-time monitoring. Advances in a combination of wearable biosensors to detect neuromuscular fatigue, surface testing equipment and machine learning could help predict individualized cramp risk. Coaches might then adjust practice plans, make in-game substitutions or even adapt surface conditions when possible.

By better preparing athletes for the mechanical demands of competition surfaces, teams may protect their athletes’ health and ensure top performers are available when the game is on the line.

This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Michael Hales, Kennesaw State University

Read more:

• Your mighty tendons help you sprint, jump and move – a genetic mutation in one key protein may increase athletic performance
• Your heart changes in size and shape with exercise – this can lead to heart problems for some athletes and gym rats
• Adding more green space to a campus is a simple, cheap and healthy way to help millions of stressed and depressed college students

Michael Hales does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.