HRV AND INDIVIDUAL MONITORING OF TRAINING INTENSITY

by SEAN HOGAN
As you will now be aware when an athlete is training he or she will likely display a fluctuating HRV reading. HRV readings will fluctuate down when training intensity is high and then may return upwards to a baseline or even a supercompensation level with tapering. The important point to note is that when training hard, HRV readings may go down and with reduced training the opposite may occur.
This fluctuation of HRV scores is normal. For example a number of studies have shown that HRV reduces when the athlete is training hard or after completing an overreaching phase in training. Studies also demonstrate that an athlete’s HRV generally returns to normal after rest or reduced training load.
Our experience also agrees with these general trends. For example, Heart Rate in bpm and HRV expressed as a figure out of 100 (using ‘ithlete’), where 100 is really the optimal level that one can achieve is plotted over a 17 day period in the Table presented here.
Day
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
HRV
71
64
76
64
66
59
64
54
52
62
72
75
76
72
64
57
65
HR
64
62
63
62
62
70
68
71
74
75
64
65
63
62
63
62
63
Train
Intensity
9
5
8
7
4
At Altitude
4
4
7
7
5
3
3
Note that the average Heart Rate from Day 1 to Day 5 is 63 bpm. Little variation occurs in this as the lowest is 62 bpm and the morning heart rate only rises one or two beats.
The average HRV for this 5 day period is 68 but the HRV variation is between 71 and 64 units. Note that when we look at the Training Intensity of each of these days we can see that HRV literally tracks Training Intensity such that after Day 1 when training was very intense (and a Rate of Perceived Exertion score of 9/10 was recorded) a reduced HRV reading the next morning of 64 reflected a high stress level. The higher stress level was in agreement with a general tiredness after the intense session on the previous day, yet heart rate was at a normal morning level.
From the Table you can also see that travelling to altitude resulted in an expected increase in morning heart rate (averaging 72 bpm at altitude). HRV also decreased as expected but did track the athlete’s general perception of fatigue fairly closely. After returning to sea level the athlete’s heart rate adjusted towards a baseline morning reading of 62-63 bpm.
Note that the athlete trained easy on return to sea level (giving a rating of 4/10 for Day 11 and Day 12). HRV then peaked at 76 on the morning of the 13th day, suggesting that the athlete was good to train on that day. Training relatively intensely for two days HRV then plummeted to warn the athlete that he needed to take it lighter.
While the profile presented above is one of the clearer profiles of HRV, tracking training intensity and type and resulting fatigue of the ANS, the coach should also use other well established markers to indicate whether an athlete should rest or reduce training load or change the type of training on any given occasion.
One final point to note is that most HRV systems now use a colour coded display to make reading HRV easy. For example, ithlete uses a series of different colours to recommend if the athlete should rest, or train.
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s