The use of advanced heart rate monitoring systems has grown tremendously in recent years, and the list of professional, collegiate, and even high school athletic teams that have invested in such systems continues to grow. Heart rate systems such as Polar Team2 provide coaching staffs with extensive information to better understand training and competition demands. These systems also include software that utilizes heart rate data and personal information (height, weight, age, gender, and specific heart rate values) to calculate training loads and predict recovery time (see Figure 1 below). Armed with this information, coaches can make more informed decisions to appropriately plan and periodize training. Pre-season is undoubtedly the time of the year when this matters most. Not only is this the period with the highest injury rates, but also the greatest variation in team fitness.
Figure 1: Training Load and Recovery Curve. Training load value is indicated by the vertical black line. Recovery is separated into metabolic and muscle pain/inflammation components (left and right side of red shaded curve, respectively).
Monitoring Training Volume and Intensity
For many sports, pre-season is characterized by high volume training with short recovery periods between sessions. "Two-a-day" practices are common during this period, leading to high daily training load values for athletes. Sometimes these high loads are exclusively the results of high training volumes, but sometimes the culprit is lack of appropriate player fitness.
Players in team sports commonly begin pre-season at different fitness levels depending on their commitment to, and quality of, off-season training. Not surprisingly, fitter players are able to sustain higher intensities and manage higher volumes of training than less fit players (see Figure 2 below). With that in mind, each player's response to training must be monitored, and training sessions adjusted accordingly.
Figure 2: Heart rate responses between a fit (blue curve) and an unfit (red curve) soccer player for the same training session. The average heart rate for the fit player was 73% (training load of 127) compared to the unfit player's 84% average heart rate (training load of 173).
Pre-season is arguably the best time for higher training loads and volumes, since there is generally a need to improve team fitness, and time is needed to implement technical and tactical components. However, this is the time when training is most often mismanaged, with unfavorable consequences.
"Fit" vs. "Unfit"
The most common error made by coaches during pre-season is in the handling of "unfit" players. Heart rate data from the Polar Team2 system shows that these players consistently incur the highest session loads, and require more recovery time than fitter players. For the "unfit" players, the training sessions by themselves are typically enough to improve fitness. Yet, coaching tendency is to add extra conditioning to these athletes - either as punishment, or to accelerate fitness gains.
Figure 3a below shows predicted recovery curves for an "unfit" soccer player during the first week of pre-season training. In this example, the training load over the first three days of two-a-day practices was the equivalent of almost 4 games! The overlapping of the red recovery curves from session to session also demonstrates chronic under-recovery. For this player, adding more metabolic stress through extra conditioning would be counterproductive and could lead to an increased risk of injury and overtraining.
Figure 3a: Predicted recovery curves for an "unfit" soccer player (Endurance Level 1 Beep Test = Level 8-4) during the first week of pre-season training. The total training load for the first 3 days of practice (1335 points; equivalent to 3.8 games).
In contrast, Figure 3b shows the recovery curves during the same period for a fit player. In this case, there is very little to no overlapping of recovery curves, indicating full recovery from session to session.
Figure 3b: Predicted recovery curves for a fit soccer player (Endurance Level 1 Beep Test score = 12-3) during the first week of pre-season training. In comparison to the unfit player in Fig. 2a, predicted recovery time is much shorter. With the exception of Day 1, full recovery is achieved the same day.
As you can see from these examples, daily heart rate monitoring can be a very effective tool for avoiding both excessive training, and a lack of training stimulus. It allows for much more effective planning, and individualization of training loads and recovery. At the end of the day, training smarter is the goal, and ensuring players are fresh at the right times can lead to more wins and fewer non-contact injuries.
Train Smarter, Not Harder
Below is a list of recommendations for handling "unfit" (less fit) players during the pre-season phase:
- Additional high-intensity conditioning is not appropriate for unfit players during a period of intensive training such as the pre-season.
- Supplement low intensity non-impact conditioning such as swimming or biking around the aerobic threshold (65-70% max heart rate) to safely build aerobic capacity and improve recovery.
- Supplement high-intensity interval training only as a substitute for practice minutes. Extra running can be an effective alternative if fatigue begins to negatively effect sport-specific skill/technical development during training.
- Limit players' game minutes during pre-season and early-season games based on fitness testing and/or heart rate recovery data.
Jason Dierking (MS, SCCC, CSCS, USAW) currently serves as the Assistant Director of Sports Performance at the University of Louisville. In this role he works directly with men's and women's swimming & diving, men's soccer and cross country.
As the energy systems specialist on the Sports Performance staff, Dierking has played a key role in implementing the Polar Team2 heart rate system now employed by 11 of the Louisville athletic teams. He has advanced the use of innovative testing and tracking procedures for metabolic fitness, including VO2max and blood lactate analysis. He has become an industry leader in the area of heart rate training and conditioning, and has spoken at several regional and national clinics and conferences on the topic.
Jason is a competitive runner and triathlete, completing races such as the Chicago Marathon and Ironman Louisville.
Director of Sports Performance at the University of Louisville since 2004, Teena Murray oversees athlete development and performance for the Cardinals' 21 Olympic sports. She is also the lead performance specialist for the Cardinal women's basketball and softball teams, and an adjunct faculty member in the graduate program in Exercise Science at U of L. Outside the collegiate realm, Teena is the owner of Athlete Construction (LLC). From 2006-2010, Teena was the strength and conditioning coach for the U.S. Women's National and Olympic ice hockey teams, winning 2 World Championships and a silver medal at the Olympic Games in Vancouver in 2010.
In 19 years in the sports performance industry, Teena has worked collegiately at Cornell, UCONN and Louisville. She has also worked as a consultant with USA Hockey, the International Ice Hockey Federation, the NHL's Florida Panthers and Anaheim Ducks, and the AHL's Hartford Wolfpack.
Teena's research interests center around the performance profiling of elite athletes. She has published numerous research and practical training articles in this area, and is also a regular speaker at conferences and clinics nationwide.
A native of Canada, Teena holds a Master's degree is Exercise Physiology from UNC-Greensboro, and undergraduate degrees in Kinesiology (Wilfrid Laurier University) and Education (Queen's University). She is a Master Coach with the Collegiate Strength & Conditioning Coaches' Association and is certified by the National Strength and Conditioning Association, United States Weightlifting, Functional Movement Systems and Precision Nutrition. In 2012, Teena was awarded the Guiding Woman in Sport Award by the National Association of Girls and Women in Sport (NAGWS).