Why Norwegian 4 by 4 isn't the answer after 40

Summary

The video argues that Norwegian 4×4 intervals can improve fitness, but may not be the right starting point for people over 40 with a weak aerobic base. The presenter recommends building that base first, then gradually adding harder training.

Main training ideas

• Develop both aerobic and anaerobic fitness. Easier, steady training is presented as a way to improve the heart’s ability to pump blood, while intervals and threshold work help the body use oxygen during harder efforts. Neither approach alone is enough.
• Build an aerobic base before emphasizing intensity. Frequent hard intervals may outpace the body’s ability to adapt and raise the risk of injury or burnout.
• Keep hard days hard and easy days easy. When combining strength and cardio, the video recommends scheduling strength and harder threshold work on the same days, followed by lighter aerobic training.
• Add harder work progressively. Establish consistent aerobic training first, then introduce subthreshold work. Faster, event-specific training comes later, closer to competition.
• Distinguish subthreshold work from VO₂-max intervals. Norwegian subthreshold training is performed just below the second ventilatory threshold. In contrast, very hard VO₂-max intervals may reach around 95% of maximum heart rate. The video describes subthreshold work as less intense and easier to recover from, allowing more total training.

Assessing aerobic effort

The video describes VT1 and VT2 in terms of breathing and speech:

• Around VT1, breathing starts to rise noticeably. Conversation becomes harder, but talking is still possible.
• Around VT2, breathing is heavy and only a few words can be spoken at a time.

The video cautions that someone with a weak aerobic base may need to exercise very slowly—or walk—to stay in Zone 2. For heart-rate tracking, the presenter recommends a chest strap, arguing that wrist-based trackers may be less accurate.

MAF test

The presenter suggests the following as a simple way to track aerobic progress:

1. Estimate MAF heart rate by subtracting your age from 180.
2. Adjust the result as follows:
   • Add 5 beats if you have completed at least two years of consistent aerobic exercise.
   • Subtract 5 beats if you were ill in the previous year.
   • Subtract 10 beats after a major illness or surgery.
3. Warm up for 15 minutes, then cover the same 5 km route or distance each time by running, rowing, or cycling. Record the pace for each kilometre.
4. A pace drop of more than 10% from the first to the last kilometre is presented as a sign of a weaker aerobic base. Repeat the test over time to track changes.

Training examples by experience level

• Beginner: If you have not completed three one-hour aerobic sessions per week for three consecutive months, keep sessions easy using the MAF method or Zone 2. The video cautions that heart-rate zones can be misjudged, causing people to train too hard.
• Intermediate: Keep three weekly workouts, introduce longer sessions and some subthreshold training, and vary the balance over two weeks. Gradually extend one easy session toward two hours. After four weeks, take a recovery week with three one-hour easy sessions.
• Experienced: The suggested example is two strength sessions and five cardio sessions per week, with subthreshold work on strength-training days. Keep the weekend session easy and longer—about two hours of running or up to four hours of cycling. Take a recovery week every third week, reducing cardio to three one-hour easy sessions.

Presenters and sources mentioned

• Presenter: Unnamed host of Peak Performance 40
• WHO recommendations
• Unspecified studies on fitness-tracker and chest-strap accuracy
• The Norwegian training system
• Scott Johnston, author of Training for the Uphill Athlete
• The presenter’s coach, described as working at Alpecin-Fenix