Is There a Benefit to Training on Sand?

The physical therapists at SSOR get asked regularly about our thoughts on training methods and “fads” in training.  Fly-by-night methods are continually in the media promising better strength, speed, and performance.  One of the things we’ve been asked about recently is training on sand for increase sprint speed.  Advocates say it helps develop speed and strength while others say it’s not helpful.  As usual with most situations like this, the sports physical therapists at SSOR look to the research to guide our practice.  So what’s the verdict on training in sand?

How do you increase running speed?

Increasing speed of an athlete basically comes down to two elements: put as much force into the ground as possible and spend as little time on the ground as possible.  You can improve stride length and stride frequency, but there will ultimately be a ceiling in each athlete.  It should be obvious that because sand is so compliant, an athlete won’t be able to “get off” it as fast as training on land.  Secondly, if we look at Newton’s laws, Newton’s third law states that for every action, there is an equal and opposite reaction.  With a firmer surface, more “push” will be given from the firm ground.  That said, a solid strength base will allow an athlete to put more force into the ground.  So, a strong push from an athlete leads to an equal push from a firm ground.  Lastly, it’s important to talk about stiffness of muscle, or resistance to deformation.  Muscle tendons are like springs – the stiffer they are and the more they’re stretched, the more explosive they are.  Muscle get stiff from strength training (this is good “stiff” – do not confuse this with inflexibility).  Well, ground is far more “stiff” than sand is.  Athletes training on sand can’t take advantage of the stiffness as much on sand because it doesn’t provide a firm base from which to explode off of.  Therefore, training on ground is more efficient for the athlete.

Why train in sand?

Training in sand has a few advantages.  For athletes training on land regularly, sand is a refreshing change of low impact training.  Plus, who doesn’t love the surf and sand?!  Training in sand is a welcome change from what can be monotonous training.  From a physiological and biomechanical standpoint, several studies (Pinnington & Dawson, J Med Sci Sport 2001; Pinnington & Dawson, Eur J Appl Physiol 2001; Pinnington et al, Eur J Appl Physiol 2005; Zamparo et al, Eur J Appl Physiol 1992) have shown a higher energy cost on sand, so you’ll work harder to go the same distance.  Furthermore, there is an increase in forward trunk lean, hip flexion range of motion, ankle plantarflexion range of motion, and an increase in the amount of steps athletes have to take (Binnie et al, J Strength Cond Res 2013).   The three components (trunk, hip, ankle) lead to improved “triple extension” needed for sprinting and jumping (see pic below).  Increased cadence is important because one method to increase speed is with increased stride frequency, and sand can help with that.  More hip flexion means greater “push off” forces (similar to a hammer going into a nail – the higher the hammer, the more force in the nail).  More ankle plantarflexion also leads to greater “push off” forces.

What do the studies on training in sand show?

There aren’t many studies on sand training.  Binnie et al investigated the effects of sand v. grass training on 20-m sprint performance (J Strength Cond Res, 2013).   One group trained on grass and the other on sand and they studied improvement in 20-m sprint performance over the course of the training period.  Researchers found that sand training improved sand sprint times, but training on grass improved both sand and grass 20-m sprint times.
An older study published in the Journal of Strength and Conditioning Research (Yigit & Tencel, 1998) looked at 6 weeks of road v. sand training on calf circumference, vertical jump, and a 12-min fitness test.  All variables improved in each group, but the sand group had statistically significant improvements in the 12-min endurance test.
In another yet to be published study in the Journal of Strength and Conditioning Research, a group of soccer players trained on sand or grass and performance measures were compared after the training sessions consisting of vertical jump, repeated sprint ability, and a 3-km timed run.  While there were no differences in performance training, rating of perceived exertion and higher heart rate in sand.

Bottom line: Training on Sand

We recommend training on sand if, say, you are a sand volleyball player.  It’s evident from the limited studies we have that training on sand makes you faster on sand.  Thus, like most training methods, specificity of training is paramount.  Furthermore, it is clear that sand training is more fatiguing and is more metabolically taxing.  Therefore, it may be a way to get greater heart rate or exertion during a workout or to get a tough workout in when resources are limited.  Another benefit might be to work on components of speed training – more hip flexion, more ankle plantarflexion, and increased steps.  What hasn’t been discussed to date however is what may be a psychological benefit – no one is ever unhappy at the beach!  Sand training is a nice alternative when training plateaus, boredom, or staleness in training occurs.   In summary, training on sand shouldn’t be something that a ground-based athlete does on a regular basis if speed and power development are the objective.  Training on sand should be something done every now and then to provide a different training stimulus.
The sports physical therapists at SSOR understand how to manipulate training variables to get you best outcome you seek.  It would be a privilege to partner with you in your care.  (913) 728-8599