VBT Series Part 6: Strength Testing with Velocity Data
Using VBT to assess changes in physiology and performance
Reminder: There’s still time to join the “Chasing Excellence” virtual conference this weekend. I’m presenting on strength training for the transition of pre-season to in-season, as junior and collegiate rowing programs move from winter building to spring performing. Details and registration here under the “Chasing Excellence” tab.
Last time in the velocity-based training (VBT) series: Video demos of the three-zone VBT system and strength training program snapshots.
We used VBT in a training context only for months before we used it for testing and specific evaluation. I think this is best practice from an athlete perspective to understand the technology and its uses before having to perform with the technology. It also allowed us to collect many sessions of athlete data without yet trying to analyze the data. We trained normally, building up a good base of information before trying to use VBT to guide training practices.
I think that strength testing can be helpful if it’s meaningful to the athletes. I dislike testing for the sake of testing, or feeling like we have to test to know if we’re improving. Even without VBT, we should know if we’re improving based on our training log and recording of weights, sets, reps, and, most importantly, our actual sport performances. True max strength tests don’t offer enough information for endurance sport performance to be worth the loss of training time and risk of athlete injury for me.
VBT offers another form of tracking progress via training data without formal testing. I already like to repeat the sets and reps for certain training sessions every 4-8 weeks and see if we can increase amount of weight across all sets or just one set. With VBT, even if the athlete doesn’t increase the weight for the same sets and reps, we can look at average velocity to see if their speed has improved as another element of improvement. For example, if an athlete squats 135lbs for 3 sets of 5 reps at an average velocity of 0.56m/s, and four weeks later squats the same with an average velocity of 0.64m/s, the increased speed suggests that 135lbs is a smaller percentage of max strength, so the athlete probably got stronger.
When specific testing is relevant and meaningful to the athletes, VBT yet again offers a significant advantage over a testing approach that only measures weight or reps. Without velocity data, strength tests tend to be performed to either technical failure, the point at which the athlete cannot do any more reps or weight with good technique, or muscular failure, the point at which the athlete cannot do any more reps or weight using any technique. There are two major disadvantages to this kind of test. The first is that the fatigue-induced deterioration of movement quality weakens the transfer to sport performance. The second is that breaking technique and pushing to the point of anything-goes exertion increases risk of injury for the athlete.
VBT adds a much more useful element of “velocity failure. This is the point at which the athlete cannot do more reps or weight above a certain velocity threshold. Setting a minimum velocity threshold helps keep the athlete away from both technical and muscular failure and focused on power-per-rep, a much more relevant physical element of sport performance transfer.
We have done a few types of VBT strength testing so far with the rowers, skiers, and biathletes at Craftsbury.
We did a formal testing panel with the ski team, spending an entire session testing four exercises. This worked OK, but not great, and I’m not sure it was a worthwhile use of the training session and the necessary recovery following intense testing. Our testing panel consisted of:
One set per leg of rear-foot-elevated split squat (RFESS), using a 35lb kettlebell for women and a 53lb kettlebell for men, until 0.5m/s velocity failure. The athlete received concurrent feedback via the iPad display, so they knew their speed on each rep and could pace how they wanted.
Between legs, we tested max reps on pushup using full range-of-motion and a 70bpm metronome marking the top and bottom positions.
After the second leg of RFESS, we tested a top-position chin-up hold for time.
The final test was a hex bar deadlift 1RM above 0.5m/s. Athletes added 10-20% bar weight for each set of one rep until the concentric lifting speed was below 0.5m/s. Athletes got one repeat opportunity for a speed below 0.5m/s. For example, a few athletes hit 0.48m/s, rested 3-4 minutes, then repeated that weight to achieve 0.5m/s to record a successful rep.
My preferred approach is to repeat “indicator sessions” to assess progress every 4-8 weeks. This is what I described earlier, repeating certain training sessions and looking for average improvement across all sets and/or specific improvement on an individual set. VBT offers an additional way to quantify progress beyond only weight and reps.
One rower did the following hex bar deadlift session: 225x8@0.51m/s, 235x6@0.54m/s, and 245x4@0.52m/s. Four weeks later, she did 225x8@0.56m/s, 245x6@0.5m/s, and 265x4@0.45m/s. We could look at this as 705lbs total at an average velocity of 0.52m/s versus 735lbs total at an average velocity of 0.50m/s.
Another rower did the same session, but the sets of 7 and 5 reps were really warmups for the final set of 3 reps. This is essentially a 3-rep max above a velocity threshold of 0.5m/s. This rower improved from 315x3@0.56m/s to 365x3@0.52m/s six weeks later. Holding velocity roughly equal suggests that this significant gain in weight moved is more “real,” as well. The rower did not go too light on the first 3RM (the speed would’ve been higher), nor did he load up and grind out the second 3RM (the speed would’ve been lower).
We have also done max-rep testing to a preset velocity drop. I’ll write more about this as a training method in the next part to this series. As a testing method, we selected a weight around 80% of 1-rep max, and then did max reps with that weight until the velocity dropped below 10% of the maximum rep velocity within that set. The rower achieved 7 reps with 245lbs on hex bar, before the 8th rep was more than 10% slower than the fastest rep. Four weeks later, she achieved 10 reps with 245lbs, before the 11th rep was more than 10% slower. The average set speed was the same on both sets around 0.46m/s. Again, this system offers multiple ways to improve: weight, reps above threshold, and average set velocity.
Next time: More VBT training program methods beyond the simple three-zone system.