While VBT (velocity based training) is a great way to monitor workouts on a day to day basis and adjust training loads based on how you’re feeling in a particular session, it doesn’t always provide a picture of what’s happening over time. Traditionally, strength training has been quantified in different ways. Here are a few examples:
Volume Load (VL) - reps x sets x load
For instance, an athlete who performs 8sets of 2reps at 250lbs for a back squat would have a volume load of 4000lbs. Look at figure 1 - each number on the x-axis represents 1 week, which means that each bar graph represents the total amount of load an athlete lifted in that week.
Time under tension (TUT) - total repetition time
TUT can be calculated in the concentric phase only, the eccentric phase only or both phases combined. TUT is generally calculated in seconds (but can also be expressed in milliseconds). TUT is often used within bodybuilding, the reason - many bodybuilders use slow tempo lifting to enhance the metabolic response. The result is an increase in TUT.
The Drawbacks of VL and TUT
Although both of these metrics are better than using nothing at all, they are missing key parameters within a movement. Let’s take a look at what they lack:
- VL cannot be used for exercises that have no external load, like jumping exercises because of the dynamics involved in a jump - for example, it’s impossible to track a countermovement jump, with VL.
- Neither VL nor TUT take into account actual force produced during a movement nor the displacement of the bar during a lift.
- TUT does not account for body mass or external load.
Most coaches use VL to keep track of the amount of volume their athletes are lifting but because of the drawbacks mentioned, there are obvious limitations that exist. Is there an alternative? The answer is a big emphatic YES!
Enter Total Work (TW)
TW is not a something new, it’s a metric that is recognized by sport scientists (McBride et al., 2009); however, because it’s been limited to research settings, application has been scarce….until now. With advancements in technology, TW is a metric that is not only possible to extract, but may become the de facto metric coaches use to monitor the amount of stress that’s being imposed on an athlete.
Some Features of TW
- It’s expressed in Joules (J) or kiloJoules (kJ).
- It takes into consideration actual force produced during a movement, distance traveled during a movement (i.e. range of motion) and the velocity of the movement.
- Both the eccentric and concentric phases of an exercise are calculated using TW.
The engineers at PUSH have spent the last year researching, collecting data and developing algorithms to accurately monitor strength, TW is the result of this diligent work. TW for every rep is calculated and the sum of all these reps represents the amount that you’ve exerted yourself on that day. Look at the screenshots below, this is what you'll see on your PUSH app - this information is useful to keep track of an individuals weight training activity and whether they should pull back or push forward in their next session. In the next section we'll compare TW to VL and dig deeper into why TW kicks ass.
Figure 2. Total Work Activity
Two Reasons TW Outweighs VL
- It’s safe to say that two exercises will not impose the same amount of stress on an athlete or individual. For example, a back squat poses more stress than a hamstring curl even if the loads are matched because more joints are involved and the athlete moves a greater distance (or through a greater range of motion) - the result is more mechanical stress on the individual.
- If two athletes are squatting, and both use the same load (350 lbs) and perform the same amount of reps (3), their VL would be the same, 1050 lbs. But what if I told you that 1 of the athletes only moved the load to a half squat position while the other did a full squat, should that represent the same amount of stress? Or what if athlete A is 6’5” while athlete B is 5’11”? The range they go through is completely different and the stress imposed on their body is therefore different. If comparing these athletes by utilizing TW, in both instances, the athlete that moves the same load a greater distance, will have a higher TW output. Figure 3 show this comparison in detail.
Figure 3. TW vs VL Comparison
McBride et al compared VL, TUT and TW with 3 different training protocols - one for hypertrophy, one for strength and one for power. Their conclusion, TW is the most appropriate metric to determine resistance training volume/stress.
Monitoring workouts has never been so simple.
McBride et al 2009. Comparison of Methods to Quantify Volume During Resistance Exercise. Journal of Strength & Conditioning Research.