The effects of strength training on endurance athletic performance have long been the subject of debate among athletes, coaches, and sport scientists. Endurance athletes typically love to train their sport, but have a hard time incorporating the correct type of strength training into their physical preparation, some might say they are allergic to the weight room.
Many voice their concern that strength training will have negative side effects on their performance with the most common concern becoming heavy and slow from lifting weights resulting in increased hypertrophy aka more body mass to carry around events.
Other areas of concern when strength training is brought up in endurance training circles include compromised VO2 max, reduced capillarisation and blood flow, and reduced energy enzyme metabolism. When the correct type of strength training has been implemented, there has been no evidence of these negative physiological and performance effects.
I am a firm believer that strength training, when executed intelligently, is a great tool for endurance athletes to use as part of their total physical preparation program. There are many reasons to argue for strength training, however they all ultimately boil down to 2 main categories.
- Injury Reduction
- Improved Performance
There is no denying that getting injured sucks! It means time away from your sport, doing what you love and missing opportunities to train, compete and get better. After working with many endurance athletes 2 things have become apparent:
Firstly, they often neglect weight training, or if they do perform resistance training, it closely mimics their sport i.e. low weight, with high repetitions.
Secondly, they are very often training around niggles and injuries. While it is impossible to fully prevent injuries, strength training is a great way to increase the resilience of an athlete and reduce the likelihood of them occurring. Injuries happen when the load applied to the body exceeds its capacity to tolerate that load. This can occur in a one-off effort e.g. tearing your hamstring, or cumulatively over time e.g. bone stress reaction.
Injury = Load > Capacity
As you can see in the equation above we can reduce the chance of injury in two ways, better managing load, or by increasing capacity. One way to raise the ceiling where injury may occur is by using strength training to build strong muscles, tendons, bones and other connective tissue. A stronger athlete is harder to break!
In general, a coach and athlete can employ with confidence concurrent endurance and strength training to improve athletic endurance performance.
The list of potential positive performance effects includes: improved endurance performance, improved maximal speed and power output, reduced or delayed fatigue, improved lactate threshold, improved exercise economy and improved anaerobic capacity. Let’s compare these to driving a car, strength training will improve the fuel economy from getting more km’s per litre of fuel, meaning less energy burned for the same output. It can also increase the size of your engine meaning you can travel at 110km/h vs 100/km/h. Essentially you can go harder for longer, using less energy.
The main physiological changes that are occurring to improve exercise economy and efficiency revolve around the nervous and the musculotendinous systems. Let’s take a deeper dive into the mechanisms at play.
- Improved Neuromuscular efficiency – when we strength train we increase the ability of our central nervous system to recruit muscle to complete movement, more specifically our motor unit recruitment of muscle fibres. Which means we get better at switching on the right muscles at a lower energy cost.
- Postponed activation of the less efficient type II muscle fibres – increasing maximal strength of type I fibres postpones their time to exhaustion delaying the activation of the less fatigue resistant type II fibres. Let’s say your lower body strength is currently 50kg for a 1RM Split Squat (maximum amount of weight you can lift once) and you improve this to 100kg, you have now increased your maximal force and peak force. Each time muscle fibre tension is developed at the same exercise intensity, let’s say 20kg of force, after strength training this results in that exercise using a lower percentage of your maximal strength. 20kg/50kg = 40% vs 20kg/100kg = 20%
- Improved Musculotendinous stiffness – the musculotendinous unit acts like a spring that stores and releases energy. When we have the right amount of stiffness in the muscle-tendon unit we can better utilise this energy to help with the running action and we will be getting energy back from the ground every time our foot strikes the floor. Improved utilisation of elastic energy in the muscle-tendon system reduces the energy demands and improves running economy. As you can appreciate during an endurance event the sporting action needs to be repeated for the duration of the race. If we take Eliud Kipchoge’s recent sub 2hour marathon (what a freak!) there was ~22,505 foot strikes.
As previously mentioned the apprehension of incorporating strength training is athletes think it will negatively impact their performance. While there may be some short-term decrease in performance associated with strength training e.g. fatigue and impaired training performance, the long-term benefits of a well-structured program will far outweigh these perceived negatives. When designed by a professional these effects can be mitigated.
Below are some effective ways of implementing strength training into a busy endurance training program.
- Use the correct type of weight training – heavy strength training and explosive concentric lifts have been shown to have the biggest impact on performance.
- Periodise your strength training – Dedicate time in your training year to getting strong where endurance training isn’t as big a priority e.g. in the off season. Shift to maintaining your strength in season when endurance training volumes are high.
- Program strength work around your sport – ride, swim, run, so they don’t heavily impact one another. Aim for 8 hours gap between strength and endurance sessions and keep your lifting days away from your main ride or run of the week.
- Implement dynamic warm ups – for your swim, bike or run sessions as an opportunity to practice skill development. A well designed warm up will address movement quality, key sporting positions, mobility, stability power and strength. You now get many more opportunities to improve across the week.
- In heavy endurance training blocks utilise less volume and less eccentric components of strength training to remove muscle damage. I also recommend not introducing any new exercises during this time, the novel stimulus can be enough to create a significant amount of muscle soreness.
When strength training is thoughtfully integrated into the overall training plan of an endurance athlete the long-term positive benefits around injury reduction and improved performance are profound. As the list of positive reasons are many and any perceived negatives outcomes haven’t been substantiated in the literature or my practice, I absolutely recommend strength training to all endurance athletes I work with. My clients and I have had great success with this strategy.
I want to credit, and suggest as further reading, the article published by Rønnestad and Mujika in the Scandinavian Journal of Medicine & Science in Sports, Optimizing strength training for running and cycling endurance performance: A review