Anyone who loves running and the beach will be able to tell you that putting the two together is one of the most beautiful ways to spend an early morning or sunlit afternoon - but it can also be a bloody tough session!

A study by Lejeune, Willems & Heglund (1998) found that running on sand requires 1.6 times more energy than running on a hard surface primarily due to a decrease in the muscle-tendon efficiency. This has been shown to allow runners to perform sprint sessions at maximum intensity with higher energy expenditure and greater metabolic power values (Gaudino, Gaudino, Alberti & Minetti, 2013). In addition to the extra force being generated by the runner, running on sand requires a greater range of motion of the ankles and hip flexors that may increase strength and flexibility (Pinnington, Lloyd, Besier & Dawson, 2005).

It has been claimed that running on sand also reduces stress injuries as a result of the reduced impact from running on a softer surface. These benefits have led to some popular running websites to claim that beach running is a great way to improve strength, fitness and running performance while preventing injury. So let's have a look at what the peer-reviewed evidence says, in conjunction with the opinion of our running experts, on the veracity of these claims.

Claim 1

Running on sand is a more intense workout than running on a harder surface

What does the peer-reviewed literature say?

Multiple studies support the claim that running on sand requires the runner to expend more energy than running on hard surfaces.

• Lejeune et al. (1998) found that running on sand required 1.6 times more energy than running on hard surfaces.

• Pinnington & Dawson (2001) found that sand running required 1.5-1.6 times more energy than on a grass surface.

• Muramatsu et al. (2006) found that jumping required 1.2 times more energy on sand than on a solid surface.

From these findings, Gaudino et al. (2013) concluded that running on sand is an effective way to perform sprint training with greater energy expenditure and higher metabolic power values than could be achieved training on solid surfaces.

What do the experts say?

“Of course, it all depends on the effort and the program, but it is true that a session of equal distances would require more effort on sand" says sand running expert Greta Truscott. "I coach soft sand every week and I've raced on soft sand and it's an amazing cardio workout, which is why it's so good.”

Trail runner Jane Kilkenny agrees, but points out that “running on sand has a different muscle demand”, so the requirements are “not completely comparable to hard surfaces”.

What are the coaching implications?

For coaches, this tells us that distances need to be adjusted appropriately to ensure that we are targeting the correct energy systems and working within the athlete's ability. Reducing distance by ~35% is a good general guide for sprint sessions (remember that acceleration is especially difficult on sand), while endurance running can be adjusted by setting a time objective rather than distance target.

Beach running is also a great option for Fartlek sessions where runners are able to adjust the pace according to how they are feeling and change how they run in conjunction with environment - for example, faster sections over the harder sections of beach and slower periods over the softer sand. However, soft sand sessions allow for lots of variety; "you can do everything you can do on a track or on the road; Fartlek, sprints, hill sessions on the dunes etc... sand running can be an intense full body workout" Greta says.

Claim 2

Running on Sand Builds Strength in the Lower Body That Running on a Hard Surface Does Not

What does the peer-reviewed literature say?

There has been a lack of peer-reviewed studies that have shown that training on sand develops muscles that training on a hard surface does not. However, there have been studies that show that running on sand works some muscle groups in the lower body more intensely than training on a hard surface.

• Yigit & Tuncel (1998) showed that in a comparison between a control group and runners on hard and soft surfaces, the runners in the sand group had a greater increase in calf circumference over the six-week endurance program. This suggests that sand running may be associated with greater overload in that muscle group than hard surface running and no running.

• Pinnington et al. (2005) identified a greater activation of the gastrocnemius of runners when running on sand than a harder surface.

What do the experts say?

Greta Truscott: "I can tell from my own running that it definitely strengthens my calves, quads, hamstrings and glutes...even the abs get a good workout because you're bracing your core for stability. Running on soft surfaces is like a strength session in itself!"

Tim Crosbie: "Soft surface running is especially useful for cross country runners, building strength in the ankle and preparing for running on uneven surfaces that they might encounter. It's also good for runners preparing for races such as the "Big Red Run", getting them use to the surface and building the specific strength that's required for running on softer surfaces.

Jane Kilkenny: "It places more stress on the calves and particularly the achilles...sand hills can also be a great way for coaches to build strength in the runner's hips and core.

What are the coaching implications?

Running on sand can be a good addition to the training program for runners looking to build strength in their lower body, core or hips. However, coaches should remember that strength is specific and therefore need to consider whether the benefits of the muscle gained from beach running are relevant to the objectives of the runner.

Claim 3

Running on Sand has a Lower Injury Risk than Running on Hard Surfaces

What does the peer-reviewed literature say?

Studies that have examined the correlation between running on sand and injury occurrence have found that running on sand increases the likelihood of some injuries, while decreasing the occurrence of other injuries compared to hard surfaces. However, further research would be required to determine whether the overall risk of injury increases or decreases with running on sand.

Evidence of Higher Injury Occurrence

• Knobloch, Yoon & Vogt (2008) found that among masters athletes, there was an increased risk of mid portion achilles tendinopathy when running on sand when compared to running on ashphalt.

• Richie, de Vries & Endo (1993) found that running on sand was correlated with increased exercise induced medial shin pain.

• Barrett, Neal & Roberts (1998) argued that the unstable nature of sand, especially dry sand, was likely to increase the risk of musculoskeletal injuries in an athlete's lower body.

• Pen, Barrett, Neal & Steel (1996) showed that among elite Ironmen, running on sand was the component of training and competition that resulted in the most numerous and severe injuries of the calves, shins and knees.

Evidence of Lower Injury Occurrence

Nigg & Segesser (1998) demonstrated that training on firmer surfaces resulted in a higher occurence of overuse injuries than softer surfaces. This was supported by Inklaar (1994) in a study of soccer players.

Ekstrand, Timpka & Haugglund (2006) found that among football players, impact-related injuries were also associated with harder surfaces.

Cressey et al. (2007) explored the possibility that unstable surface training, such as training on sand may improve balance, strength and mobility to reduce the risk of lower-limb injury in performance athletes.

Miller et al. (1998) showed that training on soft surfaces could potentially lead to lower levels of hemolysis (destruction of red blood cells) during exercise as a result of decreased forces occurring during heel-strike.

Ultimately, there is still a lack of direct causal evidence to suggest that running on sand results in a greater or lesser risk of injury than running on hard surfaces. However, there are some longitudinal studies currently being conducted that may shine further light on the effects of soft sand training for preventing injury among recreational runners and performance athletes.

What do the experts say?

Greta Truscott: "It does depend on the type of injury and the runner...as a general rule I'd say if it's an impact injury there's a lower chance because of the sand absorbing the force....[as for] instability injuries, you need to be really careful. Be considerate of the camber and unevenness of the sand."

Jane Kilkenny: "It depends on the injury...I wouldn't put anyone on the beach with a history of Achilles injuries or ongoing issues with their ankle or knee. The sand can add an extra injury risk with the extra stability challenge, however sand training can be an excellent option to add variety and intensity to training sessions."

What are the coaching implications?

While more research is required before we can say definitively what the effect that running on sand has on injury occurrence, existing research shows that the additional challenge to the lower body does increase the likelihood of certain injuries.

Coaches should be aware of the medical history of their runners and use caution when planning soft surface sessions, especially for runners with a history of Achilles issues. By contrast, runners who are particularly susceptible to impact injuries may benefit from the reduced forces experienced during running on softer surfaces.

Runners coming to soft surfaces for the first time should be encouraged to gradually increase their loading to allow for adequate time to build the unique strength required for beach running.

Coaching Tips for Soft-Surface Running

Beach Sessions

If you decide that beach running is something you'd like to incorporate into your sessions, here are some popular ideas to get you started.

Long Run: You can do your usual long run on the sand, but there are a couple of extra things to take into consideration. Firstly, every beach will have a slant and even if it is only very slight, this will put extra pressure on one side of your body, especially on your hips, knees and ankles. Planning your run as an out-and-back session will prevent the same side of the body taking the extra load for the full run. For a long run, it's better to run in the wet harder sand to avoid putting too much stress on your ankles and achilles for a long period.

Zigzags: This run uses the natural terrain of the beach to create a challenging interval session. After a light warm up, runners alternate between 1:30 to 2 minute periods running at an easy pace on the harder wet sand and 1 to 1:30 minute periods of intense effort on the softer sand higher up the beach.

Fartlek: The natural change in the environment along a coast allows for perfect conditions for fartlek sessions. One possible suggestion for runners looking to add a unique flavour is to run as close to the water's edge as possible, following the tide as it moves up and down the beach without getting wet. This will naturally create periods of increased pace as the runner escapes the larger waves as they rapidly hit the beach.

Hills: Sand dunes make for an intense hill session that aim to build strength in your hips and calves, while offering a tough cardio challenge. This is usually extra challenging as dunes usually have the softest sand on a beach, so you won't require as many reps as you do on a hard surface. Just be aware that dunes play an essential role in protecting the coastline and trampling can destroy the flora that helps keep dunes together. Be aware of local restrictions to keep off the dunes and avoid large groups using the same area.

Intervals: For groups of varying abilities, the out and back time based interval variations are an excellent option that result in everyone back in the same spot for recoveries together. Greta Truscott recommends descending intervals or pyramid intervals. In addition, coaches can use a mix of short sprints, long reps, team relays and 'In and Outs', where runners go from touching the water with their hand or foot and racing up to the promenade or bank and then back to the water.

Shoes or Barefoot?

Going barefoot is one of the factors that many runners find appealing about training on the sand, but Greta Truscott advises a gradual approach to barefoot running. "With new runners...maybe in the last 5-10 minutes of the session, have them take their shoes off and get them used to running barefoot. Then in future sessions you can slowly increase the time they spend without shoes and ease the runner into it." In addition to the extra strain on the ankles and lower body, coaches should be aware of the risk of cuts and bruises, especially when running on coarse sand and advise their runners to cover any pre-existing cuts or blisters.

Do you use soft surface training as part of your regular training environment? What advice do you have for other coaches? Let us know in the comments below.