After having time off due to injury, one of the first questions a runner or field athlete asks is ‘when can I run again?’ If the athlete has commenced running or is running at slower paces the next question is ‘when can I run faster?’ Returning to run at higher speeds can be confusing and carries with it increased risk of injury. Here we discuss a guide on returning to fast running.
Importance of High Speed Running
An essential part of a runners program is fast running. Before we go further it’s important to highlight that high speed running or sprint running are relative to the individual runner. I know many runners who wouldn’t consider themselves ‘fast’ however returning to high speed running for them is still equally important and carries with it similar injury risk. Here we use high speed running (HSR) as 85-95% of max sprinting speed or sprint running (SR) as greater than 95% of Max speed. Outside these forms of sprint running, I include fast running as anything at or faster than 5km race pace.
In order to get faster over a runner’s chosen race distance most athletes and coaches use a program consistent with the 80/20 approach (or variations of this). Where a runner performs a small amount of training (approximately 20%) at speeds faster than race pace and a large amount of training slower than race pace (approximately 80%). The combination of fast running and slower running drive the cardiovascular and musculoskeletal properties that see improvements. For field athletes high speed running and sprint running is an essential part of sporting performance. Being able to be first to the ball, outrun an opponent or make a defensive play can be the difference between winning and losing. Equally as important, performing this task requires training to ensure it doesn’t carry with it increased risk of running. Data derived from sports such as AFL and soccer indicates there appears to be a level, whereby the consistent exposure to HSR and SR, without rapid increases in the short term, is protective against soft tissue injury. Additionally higher intermittent aerobic fitness allows players to tolerate higher running volumes and changes in running volumes at reduced risk of injury. In order to optimally prepare players for these maximal velocities and high-speed elements of match-play, players require regular exposure to periods of high-speed running during training environments. The performance benefits of HSR and SR, as well as the nature of competitive sports means avoiding these activities is not possible.
Readiness to Run
Before returning to fast running it is important to use physical tests and some criteria to try and gauge one’s readiness to do so. If someone has had a week off training due to illness or a busy schedule their return to running will look different to someone who has time off due to injury as the physical capacity of their tissue has reduced. The figure below illustrates some of the muscular forces during higher speed running, where for most muscles as running speed increases muscle forces increase. Notably hamstring forces reach approximately 8x body weight and calf forces 7-8x.
In addition to muscle forces, faster running speeds see tendon loads increase and the rate of loading increase (amount of force and how quickly that force is applied). This is because our tendons behave as a spring through something called the stretch-shorten cycle. As impact occurs during running, the spring absorbs energy and compresses then recoils releasing some of that stored energy. Higher loading rates lead to more tendon contribution. For example as running speed increases there is an increased contribution from the Achilles tendon compared to the soleus and gastrocnemius muscles. However, the increased contribution from the Achilles tendon at these faster running speeds could explain the greater forces and loading rates observed which may increase the risk of injury to the Achilles tendon or limit recovery from tendinopathy. The key element to increased risk of tendon injury are the higher forces and the higher rate of force applied to the tendon which come with increasing speed.
In addition to muscular forces increasing during faster running, bone loading also increases. During loading muscle acts as an active shock attenuator assisting with the attenuation of loads on the skeleton as they are transmitted proximally. Interestingly muscular contractions on bones have been shown to produce large internal bone loads. For example tibial (shin) compressive forces were equivalent to 6-14 times body weight. The increase in compressive loads on bone with faster running speeds (and increased ground reaction/contact forces) is an important consideration following bone stress injury. Although muscle forces increase bone loading it is well established that when muscles surrounding bones become weakened or fatigued their ability to attenuate impact bone loads is lessened, resulting in increases in skeletal bone loading and heightened bone stress injury.
Now as we understand the higher levels of load on the tissues that speed imposes we need to gauge whether the injured tissue is ready for high speed running. Specific tests for return to fast running will differ depending on the injury or injured tissue. Essentially we are looking to ensure the injured tissue firstly doesn’t have a significant (>10-15%) strength difference and can withstand a fast rate of force application. This can be done in the gym with weighted tests; standing calf raises (gastrocnemius), seated calf raises (soleus), single leg hip thrust (glute max), single leg knee extension (quadriceps) and/or prone hamstring curl or NORDBORD (hamstrings). Some alternative home assessments may include:
Single leg weighted calf raises to fatigue
Single leg hip thrusts to fatigue
Side plank (off feet)
Anterior powerline plank
Side Plank > 45 sec
In addition to strength we also want to ensure our tendons (as well as muscles and bones) have been exposed to faster rates of load which as we mentioned earlier means higher overall load. Some home tests include
A-skips 3x30s
Double leg skipping (metronome set to 60-80bpm) 3×30 sec
Single leg hops 3×15
Drop Jumps 3×5
Triple hop test (less than 10% difference)
If significant differences occur between sides or there is difficulty with quicker tasks these activities alongside other accessory movements and running drills may be implemented as exercises. In a formal rehabilitation setting these exercises (or variations of) would be implemented 2-3 times per week in the weeks leading up to a return to fast running. These tests or exercises do not formally guarantee that you are ready but can be a useful indicator of readiness.
Practical Implementation
Return to faster running can be implemented in numerous ways and should always be varied according to the individual. There are numerous factors that should be considered when prescribing return to fast running programs. The following are factors that would make me more cautious in the return to fast running;
Time off due to injury (as opposed to chosen rest or illness)
Recurrent Injuries (tendon, muscle or bone stress)
Increased duration of time off running (>4 weeks)
Shorter training history (1-2 years) or previous fast running experience
Low energy availability/RED-S
The program should begin once an athlete has reached an adequate baseline of aerobic fitness, for many experienced this is considered baseline mileage. It is the distance or time run per week without increased training or specific training for a given event. Another way to consider is to take the average of the last 12-16 weeks (before time off). For most runners it is wise to be running 3 times per week for 45min before completing phase 1. The volume of high speed running should be progressed according to the demands of the individual’s sport.
Phase 1:
Run 1 – Strides – complete an easy run warm up and running drills, then just prior to the halfway point of your run complete – run 20 sec at 50 % maximum effort (on) faster than you have been running but not an all out sprint, recover and run easy 40 sec (off) x5
Run 2 – Easy
Run 3 – Long Intervals – complete an easy run warm up, running drills followed by 3 min of faster running, this is often around 10km race pace, complete 3x3min with a one minute walk.
Run 4- Easy/Long
Phase 2
Run 1 – Strides – complete an easy run warm up and running drills, then run 20 sec at 75 % maximum effort (on) faster than you have been running but not an all out sprint, go harder than phase 1, recover and run easy 40 sec (off) x5, follow this with easy running. The first 5 seconds is often building to ‘top speed’ then the last 5 seconds gradually returning to easy pace.
Run 2 – Easy
Run 3 – Long Intervals – complete an easy run warm up, running drills followed by 3 min of faster running, this is often around 10km race pace, complete 5x3min with a one minute walk.
Run 4- Easy/Long
Phase 3
Run 1 – Strides – complete an easy run warm up and running drills, then just prior to the halfway point of your run complete – run 20 sec at maximum effort (on), recover and run easy 40 sec (off) x5, follow this with easy running. The first 5 seconds is often building to ‘top speed’ then the last 5 seconds gradually returning to easy pace.
Run 2 – Easy
Run 3 – Long Intervals – complete an easy run warm up, running drills followed by 3 min of faster running, this pace can now be closer to 5km race pace, complete 5x3min with a one minute, followed walk.
Run 4- Easy/Long
Other Considerations
In addition to the guide above, some common modifications include the addition of an extra sprint session for individuals with a larger training background or higher sprint volumes required for their sport. This would look similar to run 1. In many field sports the sprints can be broken into distances rather than time, so that it appears like a 20-30m acceleration phase, 20-30m sprint effort followed by a 20-30m deceleration. This session may also be used as opposed to the longer duration intervals commonly used for middle and long distance runners (above). If previous data is available for sprinting performance this can be used as a metric to build towards. The athlete can then be timed across distances (30-50m) and comparisons made to past performance. For example if a pre-injury 50m sprint is timed to 7sec, initial return can target a 12 sec sprint for the same distance, and lower times targeted as time progresses.
Another important consideration for high speed running is the high loads on the body from the acceleration phase. For field sports this needs to be trained with a similar focus to high speed running to safely return to performance.
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