14 Dec Tempo manipulation in training
By Physiotherapist Kavan Chen
What is Tempo?
From early research until now, it has been well established in the rehabilitation world that time under tension (total time that your muscles are stressed during an exercise), neuro-modulation (how your brain perceives, reacts and adapts to the exercise stress) and increased metabolic stress have a direct correlation to improved training benefit. So how does tempo relate to these factors?
The faster you perform a movement, the more likely you’ll be harnessing elastic energy and tapping into a stretch shortening (rebounding) mechanism with minimal metabolic cost. This will allow you to do more repetitions of an exercise at a set load, compared to trying to perform this movement slowly (higher muscular fatigue and metabolic cost).
Muscular Contractions and tempo:
Let’s also go through different types of contractions that exist in an exercise. For educational purposes, we’re going to be using the squat pattern as an example. The primary movers/muscles utilised in the squat pattern would be your quadriceps and your glutes. Whilst standing upright at the beginning/top of the squat, our knees and hips are extended, meaning the joints are straight, with both the quadriceps and glutes in a shortened length.
As we begin the squatting movement, our knees and hips both start to bend (figure 1). This results in our quadriceps and glutes controlling the descent of the squat, whilst those same muscles lengthen – this is called an eccentric (or muscle lengthening) contraction. At the bottom position of the squat (figure 2) when the quadriceps and glutes are near maximally lengthened, we can either stand straight back up, or program a pause (the beauty of tempo manipulation). As you push through the ground to get upright, the target muscles contract to become shortened again, with the aim to get back to standing up straight – this is called a concentric (or muscle shortening) contraction. Once again you can either go right back down into another squat movement or pause at the top before recommencing.
Tempo examples and why they’re utilised
You will see 4 numbers, eccentric:pause:concentric:pause.
Note that an X denotes ‘as fast as possible’
Focus: Functional movement and build both strength and speed
Benefit: General strength / conditioning
Example: Walking lunges for end stage patella tendinopathy
Focus: Longer hold at end of eccentric / end of concentric movement
Benefit: Improving postural endurance and motor control
Example: Push up exercise to retrain scapula / rotator cuff stability
Focus: Slow concentric and eccentric phase (“Time Under Tension”)
Benefit: Building muscle / hypertrophy
Example: Squats early after ACL injury to target restoring a wasted quadriceps muscle
Focus: Fast / explosive movements with definite pause at start / end
Benefit: Increasing power and efficient motor patterning
Example: Heel raise progression of Achilles tendon at mid to end stage rehabilitation (RTS)
What happens in the rehabilitation world?
Through tempo training, health professionals can prescribe a sufficient training stimulus without excessive load, reducing the chances of irritating an acute (recent) injury and flaring up pain! By slowing down an exercise, you start to increase the time under tension for specific muscles and joints, as well as increasing the metabolic stress (slower movement = using more fuel) within our bodies. This ultimately results in an environment for improving both strength and muscle growth despite the lower overall load, which is very important in rehabilitation.
Slowing it down
Increasing time in the lengthening/eccentric phase allows for increased control to get into an optimal position to push out of or contract concentrically from. This helps with your bodies understanding of the movement, giving time for your brain to solidify some motor patterns and finally finding optimal biomechanical postures which help reduce injury risk.
During tempo specific rehabilitation with the overall exercise tempo being slower, the therapist has a chance to tease out and improve the technical impairments of the exercise that may be a contributing factor to someone’s presenting condition. Furthermore, a more specific range of pain free movement can be assessed when the movement is slowed down – which serves as a good indication for exercise modification. Practice makes permanent! The more time someone spends in those optimal postures (slower tempo), alongside the cuing from a knowledgeable health professional, the more likely they’ll change some of those movement habits that may be detrimental.
Just to note, a lot of research has documented the common causes of injury to be excessive loading through fatigue, changing up technique with the same load, and sudden changes of direction. Reflecting on the information above regarding slowing down the tempo, being able to decrease the absolute load whilst still getting a training adaptation and working on technique through manipulating tempo; injury risk reduction could be immensely improved.
Take a pause!
The foundation of rehabilitation is getting people stronger in their anatomical weaker links. With our previous example of the squat pattern, the hardest and most often weakest position would be at the bottom (figure 2). By utilizing a pause, we aim to keep the muscles turned on throughout those tough positions, subsequently working on strength, stability and control. Furthermore (for the case of the squat), the pause acts as a snapshot which can assess structural/mobility deficits, muscle imbalances, and pains/tweaks, as well as a time where you can hammer home some corrective cues to optimize the movement.
Control the Concentric
Most people want to power through with the concentric phase and get the weight up or stand up from a squat/deadlift. In doing so, most people lose that optimal positioning to move load. Slowing down the concentric once again puts more metabolic stress on the muscle, alongside helping people focus on which muscles are working, where they’re pushing from, maintaining optimal contact points and where their body is in space.
Return to sport and enhancing performance!
This is the part when mid-end stage rehabilitation should involve movements that replicate the demands of sport. Most of the time, this will mean bumping up the tempo and progressing to faster contractions to mimic the plyometric nature of most sports. Speed and power adaptations are directional proportionate to your training regime, you can’t expect to continue slow and controlled loading to improve power output and explosiveness. We also need to address the increased muscle endurance and repetitive joint movement required of sport – meaning that more repetitions with a faster tempo would be the more suitable stimulus.
A lot of the time, sporting injuries occur during a rapid contraction after a full muscle stretch. Health practitioners should not become complacent in addressing end stage rehab parameters, rather they should be progressing exercises and building up to faster tempos in various at risk postures to facilitate best performance.